研究者を探す
安澤 幹人
徳島大学
2024年12月20日更新
- 職名
- 教授
- 電話
- 088-656-7421
- 電子メール
- yasuzawa@tokushima-u.ac.jp
- 学歴
- 1983/3: 大阪市立大学 工学部 応用化学科卒業
1985/3: 大阪市立大学大学院 工学研究科 応用化学専攻 修士課程修了 - 学位
- 博士(工学) (大阪市立大学) (1999年12月)
- 職歴・経歴
- 1986/7: ノーステキサス大学リサーチアシスタント
1986/9: ノーステキサス大学ティーチングアシスタント
1987/11: 徳島大学 助手,工学部 応用化学科
2000/4: 徳島大学 講師,工学部 化学応用工学科
2001/8: 徳島大学 助教授,工学部 化学応用工学科
2003/11: カンザス大学客員教授
2014/2: 国立台湾科技大学客員准教授
- 専門分野・研究分野
- 電気化学 (Electrochemistry)
バイオマテリアル (Biomaterials)
2024年12月20日更新
- 専門分野・研究分野
- 電気化学 (Electrochemistry)
バイオマテリアル (Biomaterials) - 担当経験のある授業科目
- STEM概論 (学部)
STEM演習 (学部)
グローバルコミュニケーションB (大学院)
グローバルコミュニケーションC (大学院)
プレゼンテーション技法(D) (大学院)
化学環境工学特論 (大学院)
国際先端技術科学特論1 (大学院)
国際先端技術科学特論2 (大学院)
基礎無機化学 (学部)
応用化学特別講義2 (学部)
技術英語入門 (学部)
機能性材料論 (大学院)
物理化学序論 (学部)
物理化学特論 (大学院)
理工学概論 (共通教育)
科学技術論E (大学院)
雑誌講読 (学部)
電気化学 (学部) - 指導経験
- 35人 (学士), 12人 (修士), 1人 (博士)
2024年12月20日更新
- 専門分野・研究分野
- 電気化学 (Electrochemistry)
バイオマテリアル (Biomaterials)
- 研究テーマ
- 埋込型微小血糖値センサの作製, 免疫センサの開発, SPE電極を用いた有機合成, 生体適合性材料の合成, 磁気回収が可能な水質浄化用低環境負荷型凝集剤の開発 (バイオセンサ, 電解合成, インビボ測定, 生体適合性材料, SPE電解, 水質浄化)
- 著書
- 安澤 幹人 :
体内埋め込み測定用バイオセンサの開発,
株式会社 技術情報協会, 東京, 2014年4月. 安澤 幹人 :
体内埋込型バイオセンサ,
株式会社ティー·アイ·シィー, 京都, 2008年6月.- (要約)
- 体内に存在する生化学物質の濃度やその変化を知ることは,種々疾患の発見や予防,治療に有用であることから,体内および体液の生化学物質の濃度測定が可能なバイオセンサの開発が盛んに行われている.なかでも血糖値は,糖尿病の診断,治療,および健康管理に有効かつ重要な情報を提供してくれることから,血糖測定を行う様々なグルコースセンサが研究開発されている.現在,行われている血糖測定の大多数は,採血した後に使い捨て型血糖センサを用いて測定する方法であるが,1999年に米国で生体内に留置し連続測定が可能な体内埋込型グルコースセンサ Minimed CGMSの臨床応用が開始されて以降,逆イオントフォレシス を用いて体液を皮膚表面に漏出させて測定するグルコウォッチ,酵素を使わず近赤外分光法等を用いた非侵襲型のOrSense NBM-200Gやマイクロダイアリシス法を用いたMenarini Glucoday S等,血糖値の連続測定が可能なシステムが開発されており,今後は使い捨て型血糖センサに置き換わり,糖尿病患者の血糖測定の主流になると予想される.そこで本稿では,糖尿病患者の治療・健康管理に有用な体内グルコースのリアルタイムモニタリングが可能な体内埋込型グルコースセンサを開発するのに必要な要件・技術・特徴について述べる.
Fabrication and properties of needle type glucose sensors using electropolymerization procedure,
The Electrochemical Society, Inc., New Jersey, USA, Sep. 2001.- (要約)
- 電解重合法を用いた直径400ミクロンの針状グルコースセンサの作製法を解説している.酵素(グルコースオキシダーゼ)の固定は,糖鎖を有するピロール誘導体を用いることにより容易に行うことが可能である.牛血清中の測定には,センサの表面をポリウレタンで被覆することが不可欠である.またラットの体内にセンサを埋め込んで測定することについても述べている.
Development of amperometric immunosensors using positively charged ferrocene polymer,
The Electrochemical Society, Inc., New Jersey, USA, Sep. 2001.- (要約)
- 電気化学免疫センサの感度並びに精度の向上に有効な電気化学活性物質フェロセンの標識方法について解説している.センサの高感度化を目的にフェロセンを抗体等の分子識別能を有するタンパク質に結合させた場合,フェロセンが抗体等の分子識別部位にも結合するため,特異的な結合能の低下が起こる.そこで結合可能な官能基を一つしか持たないフェロセンのポリマーを用いることにより,特異的結合能を低下させることなく,高感度化(15倍)が可能であった.さらにポリマーにプラスのチャージを持たせ,静電的反発を持たせることにより非特異吸着の抑制も可能であった.
Characterization of N-substituted polypyrrole/Nafion thin film electrode having immobilized glucose oxidase,
The Electrochemical Society, Inc., New Jersey, USA, Jun. 1993.- (要約)
- 電解重合法を用いたグルコースセンサの作製法について述べている.無置換ピロールを用いた従来の酵素固定法では,酵素が安定に固定されておらず,センサ寿命が短いことが欠点であった.ピロールのN-置換基末端にカルボキシル基を導入すること並びにカチオン交換膜であるナフィオンを用いることにより,長寿命化や高選択性が可能であることを解説している.
- 論文
- Yumeng Zhao, Masashi Kurashina, Hitoshi Matsuki and Mikito Yasuzawa :
Biocompatibility of zwitterionic polymer-modified surface under acidic condition,
Modern Physics Letters. B, Vol.37, No.19, 2340033, 2023.- (要約)
- In this study, properties such as hydrophilicity and biocompatibility of surfaces prepared with 2-methacryloyloxyethyl phosphorylcholine (MPC) were evaluated under neutral to acidic conditions. The MPC-modified surface exhibit high hydrophilicity in neutral condition due to the ionization effect, while under acidic conditions below pH 3, the hydrophilicity gradually decreased due to the decrease in the negative charge of the PC groups. Biocompatibility property was evaluated by measuring the adsorption prevention effect against fibrinogen. The adsorption of fibrinogen was hardly observed on scanning electronic microscope (SEM) pictures under pH 7.6, which was significantly lower than that of the bare glass. However, the adsorption ratio increased under acidic conditions of pH 2.8 indicating a decrease in biocompatibility.
- (キーワード)
- Zwitterionic monomer / SI-ARGET-ATRP / protein adsorption / biocompatibility
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1142/S021798492340033X
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1142/S021798492340033X
(DOI: 10.1142/S021798492340033X) Quyen Hong Ho, Masashi Kurashina and Mikito Yasuzawa :
Removal of phosphate from aqueous solution by using thermally modified clamshell,
Modern Physics Letters. B, Vol.36, No.16, 2242011, 2022.- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1142/S0217984922420118
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1142/S0217984922420118
(DOI: 10.1142/S0217984922420118) Masashi Kurashina, Haoyuan Li, Shiba Keita, Morishita Yuta, Shibata Kazuki, Mikito Yasuzawa and Quyen Hong Ho :
Syntheses of D-glucamine and N-methyl-D-glucamine modified chitosan for boron adsorption,
Modern Physics Letters. B, Vol.36, No.16, 2242001, 2022.- (徳島大学機関リポジトリ)
- ● Metadata: 117473
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1142/S0217984922420015
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1142/S0217984922420015
(徳島大学機関リポジトリ: 117473, DOI: 10.1142/S0217984922420015) Toshiki Nakao, Masaki GOTO, Masashi Kurashina, Nobutake Tamai, Mikito Yasuzawa and Hitoshi Matsuki :
Temperature- and Pressure-Induced Bilayer Phase Transitions of an Amide-Linked Phosphatidylcholine: A Contrasting Effect of Chain Linkage Type,
Bulletin of the Chemical Society of Japan, Vol.95, No.2, 261-270, 2022.- (要約)
- An unnatural phospholipid with two amide linkages, dipalmitoylamidodeoxyphosphatidylcholine (DPADPC), was synthesized and its bilayer phase transitions were observed by differential scanning calorimetry under atmospheric pressure and light-transmittance measurements under high pressure. The DPADPC bilayer membrane showed different phase transitions depending on the thermal history of the lipid sample under atmospheric pressure. The thermal-history dependent transitions were also observed under high pressure. The temperature pressure phase diagram and thermodynamic quantities of the phase transitions of the DPADPC bilayer membrane were compared with those of bilayer membranes of hydrophobic chain-linkage isomers, ester-liked dipalmitoylphosphatidylcholine (DPPC) and ether-linked dihexadecylphosphatidylcholine (DHPC). The thermodynamic quantities of the main transition for these PC bilayer membranes were similar to each other, whereas the suppression of the interdigitation and great stabilization of the hydrated crystal phase were observed for the DPADPC bilayer membrane. Furthermore, the results of nuclear magnetic resonance measurements indicated that the motility of PC molecules in both gel and liquid crystal phases of the DPADPC bilayer membranes were much lower than those of the DPPC and DHPC bilayer membranes. From the above results, we concluded that the molecular interaction in the PC bilayer membranes increases in the order of ether-, ester- and amide-linkage isomers.
- (キーワード)
- Amide-linked phospholipid / Lipid bilayer membrane / 相転移 (phase transition)
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1246/bcsj.20210395
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1246/bcsj.20210395
(DOI: 10.1246/bcsj.20210395) Wahyu Diyatmika, Chia-Chi Yu, Yusuke Tanatsugu, Mikito Yasuzawa and Jinn P. Chu :
Fibrinogen and albumin adsorption profiles on Ni-free Zr-based thin film metallic glass,
Thin Solid Films, 2019.- (要約)
- In this study, we assessed the fibrinogen and albumin adsorption performance of Ni-free Zr-based (Zr53Cu33Al9Ta5) thin-film metallic glass (TFMG). Quartz crystal microbalance (QCM) system and fluorescence spectrophotometer were used to obtain protein adsorption measurements, using two different substrates (QCM and glass). Test samples were fabricated by coating both of the substrates with TFMG and Ti (widely used in implants) for comparison. In dynamic QCM as well as static fluorescence spectrophotometer tests, the TFMG achieved a lower fibrinogen to albumin adsorption ratio. The TFMG coating also exhibited high hydrophobicity (water contact angle of 96°) with low surface roughness of 1.06 nm and surface free energy of 35.3 mN/m. This is a clear demonstration of the excellent hemocompatibility of Ni-free Zr-based TFMG.
- (キーワード)
- Thin-film metallic glass / Protein adsorption / Fibrinogen / Albumin
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1016/j.tsf.2019.06.032
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1016/j.tsf.2019.06.032
(DOI: 10.1016/j.tsf.2019.06.032) Jhong Huan-Ping, Chang Sun-Tang, Huang Hsin-Chih, Wang Kai-Chin, Lee Jyh-Fu, Mikito Yasuzawa and Wang Chen-Hao :
Enhanced activity of selenocyanate-containing transition metal chalcogenides supported by nitrogen-doped carbon materials for the oxygen reduction reaction,
Catalysis Science & Technology, No.9, 3426-3434, 2019.- (要約)
- Selenocyanate-containing transition metal chalcogenides supported by nitrogen-doped carbon materials, denoted as CoSe/CN, demonstrate an excellent oxygen reduction reaction (ORR) ability with an electron-transfer number of 3.994, which is approximately equal to the ideal electron-transfer number 4.0. In an electrochemical measurement, CoSe/CN demonstrates excellent durability after 30 000 cycles. When an anion (alkaline) exchange membrane fuel cell uses CoSe/CN as the cathode catalyst, it shows high performance using a Fumapem FAA-3 membrane. The high catalytic performance of CoSe/CN is due to two reasons: 1) the presence of selenocyanate (SeCN-) bonding in CoSe/CN that promotes electron transfer and 2) the presence of the Co N structure that acts as the active site for the ORR. These characteristics of CoSe/CN enhance the performance of the active sites and increase the kinetic reaction rate during the ORR, thus making CoSe/CN a promising catalyst.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1039/C9CY00854C
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1039/C9CY00854C
(DOI: 10.1039/C9CY00854C) Yoshiaki Taniguchi, Tsubasa Miki, Yasuhide Ohno, Masao Nagase, Yukihiro Arakawa and Mikito Yasuzawa :
Observation of the interaction between avidin and iminobiotin using a graphene FET on a SiC substrate,
Japanese Journal of Applied Physics, Vol.58, No.SD, SDDD02, 2019.- (出版サイトへのリンク)
- ● Publication site (DOI): 10.7567/1347-4065/ab0544
- (文献検索サイトへのリンク)
- ● Summary page in Scopus @ Elsevier: 2-s2.0-85069540593
(DOI: 10.7567/1347-4065/ab0544, Elsevier: Scopus) Yoshiaki Taniguchi, Tsubasa Miki, Yasuhide Ohno, Masao Nagase, Yukihiro Arakawa, Yasushi Imada, Keiji Minagawa and Mikito Yasuzawa :
Suppression of protein adsorption on a graphene surface by phosphorylcholine functionalization,
Japanese Journal of Applied Physics, Vol.58, No.5, 055001, 2019.- (出版サイトへのリンク)
- ● Publication site (DOI): 10.7567/1347-4065/ab0b37
- (文献検索サイトへのリンク)
- ● Summary page in Scopus @ Elsevier: 2-s2.0-85067825146
(DOI: 10.7567/1347-4065/ab0b37, Elsevier: Scopus) Masashi Kurashina, Ikeuchi Daiki, Ohara Masaki, Toshio Takayanagi and Mikito Yasuzawa :
Syntheses and properties of copper hydroxide nanosheets and controlled deposition,
International Journal of Modern Physics B, Vol.32, No.19, 1840047-1-1840047-5, 2018.- (要約)
- In this study, we synthesized copper hydroxide nanosheet and investigated its electro-chemical property and how to deposit it with a uniform amount. The precursor of the nanosheet was a layered copper hydroxide synthesized by the ion exchange of dodecyl-benzene sulfonate (DBS) with acetate in Cu2(OH)3(CH3COO)·H2O. The nanosheet was prepared by delamination of the layered copper hydroxide by dispersion in 1-butanol. Atomic force microscopy (AFM) images of the nanosheets showed lateral dimensions of ca. 2 μm with the height of ca. 4.5 nm. Cyclic voltammogram of the nanosheet in basic solution showed two cathodic peaks and two anodic peaks similar to the copper oxide electrode. To deposit the nanosheet, a quartz glass slide was dipped in the dispersion of the nanosheet in 1-butanol and dried after washing. This procedure was repeated and the ultraviolet (UV) and visible (Vis) light absorption spectrum of the slide was measured. The absorbance of the slide increased in direct proportion to the number of times of the dip-and-dry procedure. Thus, we confirmed that a controlled amount of nanosheet was deposited on the quartz glass.
- (徳島大学機関リポジトリ)
- ● Metadata: 117477
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1142/S0217979218400477
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1142/S0217979218400477
(徳島大学機関リポジトリ: 117477, DOI: 10.1142/S0217979218400477) Thuy Thi Xuan Le, Suong Thi Le, Mai Thi Sao Nguyen, Quyen Hong Ho and Mikito Yasuzawa :
Purification of groundwater contaminated with iron and manganese by effective cost filter materials for households in rural areas,
International Journal of Modern Physics B, Vol.32, No.19, 1840079-1-1840079-6, 2018.- (要約)
- This research investigated the feasibility of effective cost filter materials for groundwater purification in the small and medium scale households in Vietnamese rural areas. The trial models could treat 30 L of groundwater with aeration flow 5 L/min for 15 min. After 24 h of sedimentation, the water was filtered through layers of gravel (h = 11 cm), sea sand (h = 11 cm), activated carbon (h = 15 cm), manganese sand (h = 12 cm), sea sand (h = 11 cm) and gravel (h = 11 cm). After treatment process, the concentration of Fe and Mn ions of the output trial models was lower than the Vietnamese standard for drinking water. The model has a simple structure and easy assembly for washing the filter materials which continued to be used for the next filtration process. These models provide in rural areas, where it promising solutions for supplying drinking water to households is difficult to get clean ground water.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1142/S0217979218400799
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1142/S0217979218400799
(DOI: 10.1142/S0217979218400799) Quyen Hong Ho, Maki Yoshioka, Masashi Kurashina, Mikito Yasuzawa and Thuy Thi Xuan Le :
Eco-friendly removal of phosphate from aqueous solution using natural dietary fibers and minerals,
International Journal of Modern Physics B, Vol.32, No.19, 1840075-1-1840075-5, 2018.- (要約)
- In this study, we focused on the investigation of phosphate removal using calcium oxide (CaO) and calcium hydroxide (Ca(OH)2) which are mainly from the calcined shells as adsorbents. Hydroxylapatite Ca10(PO4)6(OH)2, the component of industrial fertilizer was formed after the adsorption process following the XRD results. The phosphate removal increased from 20% to 97% with the aid of the mixture of flocculants alginic acid (AA), NaHCO3 and CaCl2 · 2H2O in the case of 50 ppm phosphate concentration when the samples were filtered through 2.7 μm particle retention filter paper which is roughly equivalent to the case of phosphate removal rate of 0.2 μm membrane filter paper without flocculants (99%). The results suggest that AA, NaHCO3 and CaCl2 · 2H2O as the flocculants are effective for phosphate removal from 20 to 100 ppm.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1142/S0217979218400751
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1142/S0217979218400751
(DOI: 10.1142/S0217979218400751) Masashi Kurashina, Fumiaki Suzuka and Mikito Yasuzawa :
Electrochemical Oxidation of Glucose Using Copper Hydroxide Nanosheets,
ECS Transactions, Vol.86, No.15, 23-26, 2018.- (要約)
- In this study, we synthesized copper hydroxide nanosheet and investigated electrochemical oxidation of glucose using the copper hydroxide nanosheets. The precursor of the nanosheet was a layered copper hydroxide synthesized by the ion exchange of dodecylbenzene sulfonate with acetate in Cu2(OH)3(CH3COO)·H2O. Delamination of the layered copper hydroxide prepared the nanosheet by dispersion in 1-butanol. Atomic force microscopy images of the nanosheets showed lateral dimensions of ca. 2 μm with a height of ca. 4.5 nm. Cyclic voltammogram of the nanosheet coated electrode showed oxidation current peak depend on the concentration of glucose at around +0.6 V vs. Ag/AgCl. Amperometry was measured at +0.6V vs. Ag/AgCl with successive addition of glucose solution. Glucose concentration and catalytic current were almost proportional. When the linear range is 0.1 to 4.9 mM, the sensitivity was 1.16 mA mM-1cm-2 from the slope.
- (徳島大学機関リポジトリ)
- ● Metadata: 117478
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1149/08615.0023ecst
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1149/08615.0023ecst
(徳島大学機関リポジトリ: 117478, DOI: 10.1149/08615.0023ecst) Megha A. Deshmukh, Harshada Patil, Gajanan Bodkhe, Mikito Yasuzawa, Pankaj Koinkar, Almira Ramnaviciene, Mahendra Shirsat and Arunas Ramnaviciene :
EDTA-modified PANI/SWNTs nanocomposite for differential pulse voltammetry based determination of Cu(II) ions,
Sensors and Actuators B: Chemical, Vol.260, 331-338, 2018.- (要約)
- Differential pulse voltammetry (DPV) based electrochemical sensor dedicated for the determination ofCu(II) ion concentration is reported in this research. Sensor was based on electrochemically synthesizedpolyaniline (PANI) and single walled carbon nanotubes (SWNTs) nanocomposite (PANI/SWNTs),which was additionally functionalizedby ethylenediaminetetraacetic acid(EDTA)inorder to get structure(EDTA-PANI/SWNTs) with advanced selectivity towards Cu(II) ion. Synthesis of PANI/SWNTs nanocompositewas performed by potential cycling, dodecyl benzene sulphonic acid sodium salt (DBSA) was usedas a surfactant during the synthesis of PANI/SWNTs nanocomposite to get a uniform suspension of SWNTsat room temperature. In the next step, PANI/SWNTs nanocomposite was further modified by the EDTAsolution containing 1-ethyl-3(3-(dimethylamino)propyl)-carbodiimide (EDC) as activating agent, whichis activating carboxyl groups, utilizing dip coating technique at room temperature. Differential pulsevoltammetry (DPV) technique was applied for the electrochemical detection of Cu(II) ion. DPV basedresponse of EDTA-PANI/SWNTs structure towards Cu(II) ion was investigated. Analytical signals revealthat EDTA-PANI/SWNTs structure is suitable for selective determination of Cu(II) ion in the presence ofinterfering Pb(II), Cd(II), Ni(II) and Co(II) ions
- (キーワード)
- Electrochemical detection / Cu(II) ions / Differential pulse voltammetry (DPV) / PANI/SWNTs nanocomposite / Sensor / Single walled carbon nanotubes (SWNTs)
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1016/j.snb.2017.12.160
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1016/j.snb.2017.12.160
(DOI: 10.1016/j.snb.2017.12.160) Thuy Thi Xuan Le, Mai Thi Sao Nguyen, Quyen Hong Ho, Mikito Yasuzawa and Vu Xuan Tran :
Removal of Nickel from Plating Wastewater Using the Magnetic Flocculant PG-M,
Chemical Science International Journal, Vol.22, No.1, 1-9, 2018.- (要約)
- In this study, a new kind of magnetic particle functionalized biopolymer (PG-M) was applied to remove nickel from plating wastewater. The key parameters of pH, adsorption time, the mass of adsorbent, and shaking speed were investigated to optimize conditions. Batch experiments were conducted with actual samples collected from a manufacturer having an initial nickel concentration of 143.73 mg/L at pH 5. The highest removal efficiency of Ni2+ ions was greater than 99% when 1 g/L of the PG-M material was added to the solution (pH=10) and stirred at 200 rpm for 20 min. The desorption of this adsorbent was performed in a 0.1 M solution of HCl and the removal efficiency of Ni2+ ions unchanged after nine cycles. The Ni2+-loaded PG-M magnetic flocculant was easily separated from the solution by an external magnet.
- (キーワード)
- 重金属 (heavy metals) / Nickel / 吸着 (adsorption) / PG-M
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.9734/CSJI/2018/39902
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.9734/CSJI/2018/39902
(DOI: 10.9734/CSJI/2018/39902) Megha Deshmukh, Harshada Patil, Gajanan Bodkhe, Mikito Yasuzawa, Pankaj Koinkar, Arunas Ramanavicius, Sadhna Pandey and Mahendra Shirsat :
EDA modified PANI/SWNTs nanocomposite for determination of Ni(II) metal ions,
Colloids and Surfaces A:Physicochemical and Engineering Aspects, Vol.537, 303-309, 2018.- (キーワード)
- ナノ複合体 (nanocomposite) / PANI/SWNT / Electrochemical Synthesis / Ni ions Detection / EDA
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1016/j.colsurfa.2017.10.026
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1016/j.colsurfa.2017.10.026
(DOI: 10.1016/j.colsurfa.2017.10.026) Harshada K. Patil, Megha A. Deshmukh, Sumedh D. Gaikwad, Gajanan A. Bodkhe, K. Asokan, Mikito Yasuzawa, Pankaj Koinkar and Mahendara D. Shirsat :
Influence of Oxygen Ions Irradiation on Polyaniline/ Single Walled Carbon Nanotubes Nanocomposite,
Radiation Physics and Chemistry, Vol.130, 47-51, 2017.- (キーワード)
- ナノ複合体 (nanocomposite) / Swift Heavy Ion Irradiation / Atomic Force Microscopy / Fourier Transformed Infrared Spectroscopy
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1016/j.radphyschem.2016.07.030
- (文献検索サイトへのリンク)
- ● Summary page in Scopus @ Elsevier: 2-s2.0-84980320678
(DOI: 10.1016/j.radphyschem.2016.07.030, Elsevier: Scopus) Jiang Li, Pankaj Koinkar, Yusuke Fuchiwaki and Mikito Yasuzawa :
A fine pointed glucose oxidase immobilized electrode for low-invasive amperometric glucose monitoring,
Biosensors and Bioelectronics, Vol.86, 90-94, 2016.- (要約)
- A low invasive type glucose sensor, which has a sensing region at the tip of a fine pointed electrode, was developed for continuous glucose monitoring. Platinum-iridium alloy electrode with a surface area of 0.045 mm2 was settled at the middle of pointed PEEK (Polyetheretherketone) tubing and was employed as sensing electrode. Electrodeposition of glucose oxidase in the presence of surfactant, Triton X-100, was performed for high-density enzyme immobilization followed by the electropolymerization of o-phenylenediamine for the formation of functional entrapping and permselective polymer membrane. Ag/AgCl film was coated on the surface of PEEK tubing as reference electrode. Amperometric responses of the prepared sensors to glucose were measured at a potential of 0.60 V (vs. Ag/AgCl). The prepared electrode showed the sensitivity of 2.55 mA/cm2 mM with high linearity of 0.9986, within the glucose concentration range up to 21 mM. The detection limit (S/N=3) was determined to be 0.11 mM. The glucose sensor properties were evaluated in phosphate buffer solution and in vivo monitoring by the implantation of the sensors in rabbit, while conventional needle type sensors as a reference were used. The results showed that change in output current of the proposed sensor fluctuated similar with one in output current of the conventional needle type sensors, which was also in similar accordance with actual blood sugar level measured by commercially glucose meter. One-point calibration method was used to calibrate the sensor output current.
- (キーワード)
- Continuous glucose monitoring / インビボ測定 (in vivo measurement) / Low-invasive device / Glucose oxidase
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1016/j.bios.2016.06.037
- (文献検索サイトへのリンク)
- ● Summary page in Scopus @ Elsevier: 2-s2.0-84975493829
(DOI: 10.1016/j.bios.2016.06.037, Elsevier: Scopus) Taniguchi Yoshiaki, Miki Tsubasa, Mitsuno Takanori, Yasuhide Ohno, Masao Nagase, Keiji Minagawa and Mikito Yasuzawa :
Fabrication of hydrophilic graphene film by molecular functionalization,
Physica Status Solidi (B) Basic Solid State Physics : PSS, Vol.254, No.2, 1600524-(4pp), 2016.- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1002/pssb.201600524
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1002/pssb.201600524
(DOI: 10.1002/pssb.201600524) Jinn P. Chu, Chia-Chi Yu, Yusuke Tanatsugu, Mikito Yasuzawa and Yu-Lin Shen :
Non-stick syringe needles: Beneficial effects of thin film metallic glass coating,
Scientific Reports, Vol.6, 31847, 2016.- (要約)
- This paper reports on the use of Zr-based (Zr53Cu33Al9Ta5) thin film metallic glass (TFMG) for the coating of syringe needles and compares the results with those obtained using titanium nitride and pure titanium coatings. TFMG coatings were shown to reduce insertion forces by ∼66% and retraction forces by ∼72%, when tested using polyurethane rubber block. The benefits of TFMG-coated needles were also observed when tested using muscle tissue from pigs. In nano-scratch tests, the TFMG coatings achieved a coefficient of friction (COF) of just ∼0.05, which is about one order of magnitude lower than those of other coatings. Finite-element modeling also indicates a significant reduction in injection and retraction forces. The COF can be attributed to the absence of grain boundaries in the TFMG coating as well as a smooth surface morphology and low surface free energy.
- (徳島大学機関リポジトリ)
- ● Metadata: 112324
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1038/srep31847
- (文献検索サイトへのリンク)
- ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 27573062
- ● Search Scopus @ Elsevier (PMID): 27573062
- ● Search Scopus @ Elsevier (DOI): 10.1038/srep31847
(徳島大学機関リポジトリ: 112324, DOI: 10.1038/srep31847, PubMed: 27573062) Jiang Li, Kentaro Hiura, Mikito Yasuzawa and Yusuke Fuchiwaki :
Fabrication of Low-Invasive Patch Glucose Sensors,
ECS Transactions, Vol.69, No.37, 1-5, 2015.- (要約)
- A fine tube type glucose sensor, which has a sensing region at the inside wall of fine tube tip, was prepared and applied for a minimally invasive glucose monitoring. The enzyme glucose oxidase was immobilized on the platinum surface located in the tube by the combination of electrodeposition and electro-polymerization of o-phenylenediamine. Amperometric responses of the prepared electrodes to glucose were measured at a potential of 0.60 V (vs Ag/AgCl). The tube type electrode showed good response with good linear relationship up to the glucose concentration of 22.4 M, which was actually higher than normal sensor without outer film for permeability restriction. This may due to its unique sensor structure.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1149/06937.0001ecst
- (文献検索サイトへのリンク)
- ● Summary page in Scopus @ Elsevier: 2-s2.0-84959283473
(DOI: 10.1149/06937.0001ecst, Elsevier: Scopus) Mikito Yasuzawa, Yuya Omura, Kentaro Hiura, Jiang Li, Yusuke Fuchiwaki and Masato Tanaka :
Fabrication of Amperometric Glucose Sensor Using Glucose Oxidase-Cellulose Nanofiber Aqueous Solution,
Analytical Sciences, Vol.31, No.11, 1111-1114, 2015.- (要約)
- Cellulose nanofiber aqueous solution, which remained virtually transparent for more than one week, was prepared by using the clear upper layer of diluted cellulose nanofiber solution produced by wet jet milling. Glucose oxidase (GOx) was easily dissolved in this solution and GOx-immobilized electrode was easily fabricated by simple repetitious drops of GOx-cellulose solution on the surface on platinum-iridium electrode. Glucose sensor properties of the obtained electrodes were examined in phosphate buffer solution of pH 7.4 at 40 C. The obtained electrode provided glucose sensor response with significantly high response speed and good linear relationship between glucose concentration and response current. After an initial decrease of response sensitivity for few days, relatively constant sensitivity was obtained for about 20 days. Nevertheless, the influence of electroactive compounds such as ascorbic acid, uric acid and acetoaminophen were not negletable.
- (キーワード)
- Cellulose nanofiber / Glucose sensor / amperometric sensor / Glucose oxidase / グリーンケミストリ (green chemistry) / enzyme immobilization
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.2116/analsci.31.1111
- (文献検索サイトへのリンク)
- ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 26561252
- ● Summary page in Scopus @ Elsevier: 2-s2.0-84958757688
(DOI: 10.2116/analsci.31.1111, PubMed: 26561252, Elsevier: Scopus) Watanabe Toshio, Yohei Yamada, Haruhiko Sakuraba, Mikito Yasuzawa, Toshio Takayanagi and Tomoki Yabutani :
The hydrophobic effect on electrodeposition of billirubin oxidase CotA,
Advanced Materials Research, Vol.1110, 291-294, 2015.- (キーワード)
- electrodeposition / CotA / thiol / self-assembled monolayer / Bio-fuel cells
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.4028/www.scientific.net/AMR.1110.291
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.4028/www.scientific.net/AMR.1110.291
(DOI: 10.4028/www.scientific.net/AMR.1110.291) Mikito Yasuzawa, Toba Taketo, Hiura Kentaro, Li Jiang, Pankaj Koinkar, Tomoyuki Ueki and Fuchiwaki Yusuke :
Preparation of micro-biosensor for continuous glucose monitoring,
Modern Physics Letters. B, Vol.29, No.6-7, 1540040, 2015.- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1142/S0217984915400400
- (文献検索サイトへのリンク)
- ● Summary page in Scopus @ Elsevier: 2-s2.0-84928392471
(DOI: 10.1142/S0217984915400400, Elsevier: Scopus) Hiroki Ishikawa, Hitoshi Takagi, Antonio Norio Nakagaito, Mikito Yasuzawa, Hiroaki Genta and Hiroshi Saito :
Effect of surface treatments on the mechanical properties of natural fiber textile composites made by VaRTM method,
Composite Interfaces, Vol.21, No.4, 329-336, 2014.- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1080/15685543.2013.876322
- (文献検索サイトへのリンク)
- ● Summary page in Scopus @ Elsevier: 2-s2.0-84897602584
(DOI: 10.1080/15685543.2013.876322, Elsevier: Scopus) Kazuaki Edagawa, Yusuke Fuchiwaki and Mikito Yasuzawa :
In Vivo Evaluation of Fine Needle Amperometric Glucose Sensors Implanted in Rabbit's Blood Vessel,
Journal of the Electrochemical Society, Vol.161, No.2, B3111-B3115, 2014.- (要約)
- Fine needle amperometric glucose sensors having outer membrane of heparin in addition of polyurethane/polydimethylsiloxane film were prepared and their glucose sensor properties were evaluated in phosphate buffer solution and in vivo monitoring by the implantation of the sensor in veins of rabbit ears. The sensitivity of the sensor was 2.2 μA mM-1 cm-2 and the detection limit for glucose was 77 μM (based on S/N = 3). Glucose sensors without heparin membrane showed glucose response on the day of implantation in vein, while reliable response was not obtained on the second day. On the other hand, the sensor with heparin outer membrane provided clear glucose response also after two days of implantation. This result indicated that the introduction of heparin membrane increased the biocompatibility of the sensor and improved the stability of sensor in vein.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1149/2.016402jes
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1149/2.016402jes
(DOI: 10.1149/2.016402jes) Mikito Yasuzawa, Shinya Sato, Hiroshi Nakanishi and Kazuaki Edagawa :
Fabrication of Minimally-Invasive Patch Type Glucose Sensors,
ECS Transactions, Vol.50, No.12, 83-87, 2013.- (要約)
- A fine tube type glucose sensor, which has a sensing region at the inside wall of fine tube tip, was prepared and applied for a minimally invasive glucose monitoring. The enzyme glucose oxidase was immobilized on the platinum surface located in the tube by the combination of electrodeposition and electro-polymerization of o-phenylenediamine. Amperometric responses of the prepared electrodes to glucose were measured at a potential of 0.60 V (vs Ag/AgCl). The tube type electrode showed good response with good linear relationship up to the glucose concentration of 22.4 M, which was actually higher than normal sensor without outer film for permeability restriction. This may due to its unique sensor structure.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1149/05012.0083ecst
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1149/05012.0083ecst
(DOI: 10.1149/05012.0083ecst) Le Thi Xuan Thuy, Mikito Yasuzawa and Tomoki Yabutani :
Magnetic Removal of Cesium Ions Using γ-Poly(glutamic acid)-Coated Magnetite Particles with the Enhanced Effect of Zeolite Supplementation,
Bulletin of the Chemical Society of Japan, Vol.86, No.8, 958-962, 2013.- (要約)
- Magnetic removal of cesium ions (Cs) by γ-poly(glutamic acid)-coated magnetite particles (PGA-MPs) was investigated using a variety of waters. Cs was sufficiently removed from fresh water in a pH range from 7.0 to 9.0, with a removal efficiency of higher than 80% by using 5 wt % PGA-MPs, while that from artificial seawater was limited to 30%. Zeolite particles were employed as a supplementary adsorbent to adsorb Cs before the collection of zeolite with PGA-MPs. The addition of 1 wt % zeolite particles enhanced the recovery of Cs up to 97.7 ± 0.2% for fresh water and the amount of PGA-MPs required for the treatment was reduced to 0.2 wt %. Nevertheless, such improvement was not observed for artificial seawater treatment. The zeolite supplementation method performed sufficiently on the recovery of Cs in tap water and spring water, and their recoveries were both higher than 93% with R.S.D. of less than 1%. These results strongly suggest that the provided procedure can be practically applied to the removal of Cs from various inland waters.
- (キーワード)
- General Chemistry
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1246/bcsj.20130020
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1390001204143050880
- ● Summary page in Scopus @ Elsevier: 2-s2.0-84882931888
(DOI: 10.1246/bcsj.20130020, CiNii: 1390001204143050880, Elsevier: Scopus) Kazuaki Edagawa and Mikito Yasuzawa :
Preparation of Fine Implantable Needle Type Biosensors for Blood Vessel Glucose Monitoring,
ECS Transactions, Vol.50, No.12, 401-405, 2012.- (要約)
- Fine needle type glucose sensors with variety of outer membrane were prepared and their glucose sensor properties were evaluated by in vitro measurement in phosphate buffer solution and horse serum, and in vivo measurement using the veins of rats and rabbits. Extra-outer membrane materials of polyglutamic acid (PGA) and heparin, which provide hydrophilic surface were introduced in addition to polyurethane/polydimethylsiloxane composite outer membrane. Glucose sensors without extra-outer film and with PGA extra-outer film showed glucose response on the day of implantation, while clear response was not obtained on the second day of implantation due to the adsorption of thrombus on the sensor surface. On the other hand, the sensor with heparin outer membrane provided satisfactory glucose response also on the second day.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1149/05012.0401ecst
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1149/05012.0401ecst
(DOI: 10.1149/05012.0401ecst) Toshio Watanabe, Yohei Yamada, Junko Motonaka, Tomoki Yabutani, Haruhiko Sakuraba and Mikito Yasuzawa :
Preparation of an electrode modified with a thermostable enzyme Bacillus Subtilis CotA by electrodeposition,
International Journal of Modern Physics: Conference Series, Vol.6, 150-155, 2012.- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1142/S2010194512003091
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1142/S2010194512003091
(DOI: 10.1142/S2010194512003091) Le Thi Xuan Thuy, Mikito Yasuzawa and Tomoki Yabutani :
Study of Mutielemental Adsorption on Activateed Carbon,
International Journal of Modern Physics: Conference Series, Vol.6, 121-126, 2012.- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1142/S2010194512003042
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1142/S2010194512003042
(DOI: 10.1142/S2010194512003042) Yusuke Fuchiwaki and Mikito Yasuzawa :
Flow immunosensing system utilizing antibodies immobilized on beads coated with poly-2-[3-(methacryloyl-amino)propylammonio]ethyl 3-aminopropyl phosphate,
Sensors and Actuators A: Physical, Vol.170, No.1-2, 100-105, 2011.- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1016/j.sna.2011.05.025
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1016/j.sna.2011.05.025
(DOI: 10.1016/j.sna.2011.05.025) Juan Zhang, Hui-ping Deng, 薮谷 智規, 安澤 幹人 :
Study of the Removal of Pb2+ from Aqueous Solution by Poly-γ-glutamic Acid Coated Magnetic Nanoparticles,
Journal of Environment Science, Vol.32, No.11, 3348-3356, 2011年.- (要約)
- In this study, a novel low cost magnetic adsorbent material prepared by poly-gamma-glutamic acid (gamma-PGA) coating Fe3o4 magnetic particles, which was called coated magnetic namoparticles (PG-M) was developed for the removal of Pb2+ from water by Dr. Yasuzawa. The particle size of PG-M was about 120-320 nm, and there was no significant difference in Fe3O4 and PG-M particle size, Fe3O4 was only as the support of PG-M core and did not directly involve in the reaction. The shape of PG-M was irregular cubic structure. The experiments were applied to quantify adsorptive time, pH, competitive ion and organics on the removal effect of Pb2+. The results showed that PG-M was effective in removal of Pb2+; the equilibrium amount of adsorptive was as high as 93.3 mg/g and the optimized condition of pH value for metal ions removal was 7.0, while contact time was about 45 min. The removal efficiency of Pb2+ was not significantly influenced by Na+ while was reduced with the increasing concentration of Ca2+. The removal of Pb2+ was enhanced with the presence of organic matter (humic acid, HA) when the concentration of HA was below 5 mg/L, and decreased when the concentration of HA exceeded 5 mg/L. Langmuir isotherms fitted the experimental data better compared to Freundlich isotherms. Pseudo second order model well described the sorption kinetics of Pb2+. The used PG-M can be desorbed by 0.1 mol/L HCl and became reusable. PG-M is nontoxic and eco-friendly, which have a good prospect in water treatment.
- (キーワード)
- Adsorption / Lead / Magnets / Nanoparticles / Polyglutamic Acid / Solutions / Water Pollutants, Chemical / Water Purification
- (文献検索サイトへのリンク)
- ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 22295634
- ● Search Scopus @ Elsevier (PMID): 22295634
(PubMed: 22295634) Yusuke Fuchiwaki, Mikito Yasuzawa, Norimichi Futagami and Kotaro Rikitake :
Improvement of accuracy in flow immunosensor system by introduction of poly-2-[3-(methacryloylamino)propylammonio]ethyl 3-aminopropyl phosphate,
Journal of Sensors, Vol.2011, No.507047, 1-10, 2011.- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1155/2011/507047
- (文献検索サイトへのリンク)
- ● Summary page in Scopus @ Elsevier: 2-s2.0-80053538483
(DOI: 10.1155/2011/507047, Elsevier: Scopus) Mikito Yasuzawa, Kazuaki Edagawa, Takuya Matsunaga, Hiroki Takaoka and Tomoki Yabutani :
Highly Selective Needle-Type Glucose Sensors Prepared by the Immobilization of Glucose Oxidase on γ-Polyglutamic Acid Film,
Analytical Sciences, Vol.27, No.3, 337-340, 2011.- (要約)
- Fine needle-type glucose sensors with an outer diameter of less that 0.2 mm were fabricated using a low-cost biodegradable γ-polyglutamic acid (PGA) not only as a glucose oxidase (GOx) immobilizing material but also as a permselective inner membrane. PGA film was prepared on cellulose acetate-coated Pt-Ir wire electrode, and GOx was covalently immobilized on its surface using water-soluble carbodiimide. The obtained electrode was practically not affected by the existence of electroactive compounds and provided long-term stability for approximately one month. It also functioned in horse serum with good linear relationship between the current and glucose concentrations within the range of 2.8 to 22.4 mM.
- (キーワード)
- Animals / Biocompatible Materials / Biosensing Techniques / Blood Glucose / Cellulose / Dimethylpolysiloxanes / Electrodes / Enzymes, Immobilized / Glucose / Glucose Oxidase / Horses / Membranes, Artificial / Needles / Polyglutamic Acid / Polyurethanes
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.2116/analsci.27.337
- (文献検索サイトへのリンク)
- ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 21415521
- ● Search Scopus @ Elsevier (PMID): 21415521
- ● Search Scopus @ Elsevier (DOI): 10.2116/analsci.27.337
(DOI: 10.2116/analsci.27.337, PubMed: 21415521) 安澤 幹人, 二神 規通, 渕脇 雄介, 薮谷 智規, 本仲 純子 :
ダイオキシン計測のための表面プラズモンイムノセンサー用感応膜の試作と評価,
分析化学, Vol.60, No.1, 81-86, 2011年.- (要約)
- For the development of a sensitive and accurate immunosensor, the production of a highly specific surface to the corresponding antibody is essential. Moreover, a specific surface having good reusability is worthwhile for constructing a prompt auto-monitoring immunosensing system. In this study, antigen analogous-modified gold substrates having a specific adsorption property to an anti-dioxin antibody, were prepared by the immobilization of 2,4,5-trichlorophenoxy (TCP) derivatives on a gold surface using various methods. An anti-dioxin antibody, which has a good correlation immunoaffinity with the total toxic equivalent quantity (TEQ) of polychlorinated dibenzo-p-dioxins, was employed as a specific antibody, and the specification of the surface was evaluated by a comparison of the surface plasmon resonance (SPR) responses to a specific anti-dioxin antibody and non-specific anti-hemoglobin antibody. In order to obtain a firm and stable immobilization of TCP, a carboxyl group was introduced on gold by a self-assemble monolayer (SAM) technique, and TCP derivatives were attached to the SAM surface with covalent bonding directly and indirectly through the presence of a hexamethylene chain, bovine serum albumin (BSA), and ethylene glycol oligomer (EGO). A TCP derivative-immobilized substrate, prepared using BSA, showed poor reusability. A TCP derivative-immobilized substrate having EGO was highly specific to an anti-dioxin antibody, while that prepared by the direct immobilization of TCP and with introduction of a hexamethylene chain presented nonspecific adsorption. In addition, a TCP derivative-immobilized substrate having EGO showed a good reproducible response from the second repetition, and was reusable more than seven times.
- (キーワード)
- immunosensor / reusable antigen analogous-immobilized surface / polychlorinated dibenzodioxin / non-specific adsorpsion / ethylene glycol oligomer / surface plasmon resonance
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.2116/bunsekikagaku.60.81
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1390001204354956288
- ● Search Scopus @ Elsevier (DOI): 10.2116/bunsekikagaku.60.81
(DOI: 10.2116/bunsekikagaku.60.81, CiNii: 1390001204354956288) Sachiyo Kamitani, Yuka Arai, Yuki Konishi, Shinsuke Nakanishi, Takuya Oshima, Junko Yamaguchi, Arisa Ishii, Keiji Minagawa and Mikito Yasuzawa :
A Senior High School Chemistry Laboratory Class Observed by University Students,
Journal of Engineering Education Research, Vol.13, No.5, 15-19, 2010. Mikito Yasuzawa, Keiji Minagawa, Sachiyo Kamitani, Yuka Arai, Yuki Konishi, Shinsuke Nakanishi, Takuya Oshima, Junko Yamaguchi and Arisa Ishii :
Production of Chemistry Laboratory Class for Senior High School Freshmen,
Journal of Engineering Education Research, Vol.13, No.5, 55-60, 2010.- (要約)
- Chemistry laboratory class was produced for senior high school freshmen with the cooperation of university staffs, high school teachers and the university students. Although the students who will take the lab class are senior high school freshmen, we decided to prepare four experiments that are simple and have highly visible reactions or transformation. That is, 1) Water purification, 2) Surface modification, 3) Briggs-Rauscher reaction, and 4) Polymer synthesis and characterization. After the safety guideline and experiment instructions by the faculty staffs, two teaching assistants (TAs) supervised each experiment. Since taking a direct part in it will provide stronger impact than only being one who is just watching the experiment, all experiments contained some process that the high school students must handle the reagents, tools or the equipment, by themselves. Although, the operation performed by the students was limited to a series of simple actions, the various unique phenomena presented by the experiments impressed the students. The lab class was fruitful not only for high school students, but also good for university students. The lab class provided good opportunity for them to improve the abilities to teach and guide someone.
Synthesis and Electropolymerization of Phosphorylcholine-Containing Pyrroles and their Hemocompatible Properties,
Analytical Sciences, Vol.26, No.5, 539-543, 2010.- (要約)
- A series of N-substituted pyrroles having phosphorylcholine with different methylene chain length between pyrrole group and phosphorylcholine group, were synthesized and the electropolymerization was performed in aqueous solution. The methylene chains were trimethylene (n = 3), pentamethylene (n = 5), nonamethylene (n = 9), and undecamethylene (n = 11), for 3-(1-pyrrolyl)propyl-2-(trimethylammonium)ethyl phosphate (5a), 5-(1-pyrrolyl)pentyl 2-(trimethylammonium)ethyl phosphate (5b), 9-(1-pyrrolyl)nonyl-2-(trimethylammonium)ethyl phosphate (5c), and 11-(1-pyrrolyl)undecyl-2-(trimethylammonium)ethyl phosphate (5d), respectively. Although electropolymerized films were produced from all pyrrole derivatives, thick and black polymer films were prepared from 5a, 5b and 5c. Pyrrole derivative with long methylene-chain 5d provided only colorless or slightly blackish thin film. Hemocompatibilities of the polymer from 5a, 5b and 5c were evaluated by platelet rich plasma (PRP) contacting studies and scanning electron microscopy (SEM) observation. The results indicated that these polymers have excellent hemocompatibility.
- (キーワード)
- Biocompatible Materials / Blood / Blood Coagulation / Electrochemistry / Humans / Methane / Microscopy, Electron, Scanning / Phosphorylcholine / Platelet-Rich Plasma / Polymers / Pyrroles / Solutions / Water
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.2116/analsci.26.539
- (文献検索サイトへのリンク)
- ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 20467127
- ● Search Scopus @ Elsevier (PMID): 20467127
- ● Search Scopus @ Elsevier (DOI): 10.2116/analsci.26.539
(DOI: 10.2116/analsci.26.539, PubMed: 20467127) Hiroki Takaoka and Mikito Yasuzawa :
Fabrication of Implantable Fine Needle Type Glucose Sensor Using gamma-Polyglutamic Acid,
Analytical Sciences, Vol.26, No.5, 551-555, 2010.- (要約)
- Implantable fine needle type glucose sensors with an outer diameter of less that 0.2 mm were fabricated using a low cost and non-animal origin polyamide, -polyglutamic acid (PGA) as a glucose oxidase (GOx) immobilizing material. Two types of PGAs, -polyglutamic acid (PGAH) and -polyglutamic acid sodium salt (PGANa), were employed to prepare GOx immobilized film by covalent attachment of GOx using water-soluble carbodiimide (EDC). Nafion/cellulose acetate composite film and polyurethane/polydimethylsiloxane composite film were employed as a permselective inner film and a biocompatible outer film, respectively. The procedure of enzyme-immobilized film fabrication affected the stability of the sensor, that is, GOx immobilized film prepared by pouring a mixture solution of GOx and EDC on a PGA precoated surface showed higher sensor stability than that prepared by pouring a mixture solution of GOx, PGA and EDC. Although, obvious differences on sensor properties were not observed between the use of PGANa and PGAH, the electrode prepared with PGAH had lower swelling degree. The glucose sensors prepared with both PGANa and PGAH were practically not affected by the existence of electroactive compounds such as uric acid, and provided long-term stability of approximately 5 weeks. These sensors showed good performance also in horse serum.
- (キーワード)
- Animals / Biocompatible Materials / Biosensing Techniques / Blood Glucose / Electrochemistry / Electrodes / Enzymes, Immobilized / Glucose Oxidase / Horses / Imides / Needles / Polyglutamic Acid / Polymers / Prostheses and Implants / Reproducibility of Results / Sensitivity and Specificity / Sodium / Solubility / Time Factors / Water
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.2116/analsci.26.551
- (文献検索サイトへのリンク)
- ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 20467129
- ● Search Scopus @ Elsevier (PMID): 20467129
- ● Search Scopus @ Elsevier (DOI): 10.2116/analsci.26.551
(DOI: 10.2116/analsci.26.551, PubMed: 20467129) 安澤 幹人, 北原 誠, 薮谷 智規, 本仲 純子 :
ナフィオン及び糖鎖を有するポリピロールを修飾した白金電極を用いた尿中グルコースのフローインジェクション/アンペロメトリック検出,
分析化学, Vol.58, No.11, 941-944, 2009年.- (要約)
- A flow-injection amperometric analysis system for the determination of glucose in human urine was analyzed. The glucose sample was mixed with glucose oxidase, and was introduced into the flow-injection system. Hydrogen peroxide produced by an enzymatic reaction was amperometrically detected by a platinum electrode modified with Nafion, and an electrochemically polymerized saccharide substituted polypyrrole. The influence of electroactive compounds such as ascorbic acid, uric acid, and acetaminophen to the glucose response observed in this system was negligible. A good linear relationship between the glucose concentration and the response current was obtained within a concentration of up to 22.4 mmol dm-3. The relative standard deviation for ten replicate analyses of 5.6 mmol dm-3 glucose in human urine was 7.4%.
- (キーワード)
- urine glucose / amperometric detection / flow-injection analysis / glucose oxidase / electropolymerization / Nafion / polypyrrole
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.2116/bunsekikagaku.58.941
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1390282679331289472
- ● Search Scopus @ Elsevier (DOI): 10.2116/bunsekikagaku.58.941
(DOI: 10.2116/bunsekikagaku.58.941, CiNii: 1390282679331289472) Masaki Tsujimoto, Tomoki Yabutani, Atsushi Sano, Yuji Tani, Hiroki Murotani, Yuji Mishima, Kenichi Maruyama, Mikito Yasuzawa and Junko Motonaka :
Characterization of a glucose sensor prepared by electropolymerization of pyrroles containing a tris-bipyridine osmium complex,
Analytical Sciences, Vol.23, No.1, 59-63, 2007.- (要約)
- A glucose sensor was developed by electrocopolymerization using pyrroles containing a tris-bipyridine (bpy) osmium complex (Os-py), pyrrole (py), pyrrole propanoic acid (PPA) and glucose oxidase (GOx) to improve the key performance characteristics, such as the sensitivity, selectivity, and long-term stability. Tris-bipyridine osmium pyrrole complexes with four different methylene moieties were utilized to correlate the methylene length with the glucose sensor performance. The electrocatalytic response of glucose was clearly observed at electrodes modified with Os-py, except for the electrode immobilized with the Os-py complex containing the shortest methylene moiety. The current response to glucose increased up to a concentration of 100 mmol dm(-3). The electrocatalytic response to glucose at the [Os(bpy)(2)(py(6)-bpy)](2+/3+)/py/PPA/GOx electrode was stable for more than 100 days. Dissolved oxygen and potential interference compounds (ascorbic acid, uric acid, and acetaminophen) minimally perturbed the current response to glucose at the [Os(DM-bpy)(2)(py(6)-bpy)](2+/3+)/py/PPA/GOx electrode. Based on these results, a longer methylene moiety appears to improve the performance characteristics of a glucose sensor fabricated via the electropolymerization of tris-bipyridine osmium pyrrole complexes.
- (キーワード)
- 2,2'-Dipyridyl / Animals / Blood Glucose / Calibration / Catalysis / Cattle / Electrochemistry / Electrodes / Glucose / Indicators and Reagents / Organometallic Compounds / Polymers / Pyrroles
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.2116/analsci.23.59
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- ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 17213625
- ● Search Scopus @ Elsevier (PMID): 17213625
- ● Search Scopus @ Elsevier (DOI): 10.2116/analsci.23.59
(DOI: 10.2116/analsci.23.59, PubMed: 17213625) Ikuichiro; Izumi, Mikito Yasuzawa and Akira Kunugi :
Indirect electroreduction of imines and diimines using a sacrificial sulfur-graphite electrode.,
Electrochemistry, Vol.74, No.8, 691-693, 2006.- (キーワード)
- Sacrificial Sulfur-graphite Electrode / Indirect Electroreduction / Imines / N-Tolylation of Aromatic Amines
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1390001206497504768
- ● Summary page in Scopus @ Elsevier: 2-s2.0-33749005374
(CiNii: 1390001206497504768, Elsevier: Scopus) Mikito Yasuzawa, Shigeru Inoue and Shinji Imai :
Preparation of Glucose Sensor Using Polydimethylsiloxane / Polypyrrole Complex,
International Journal of Modern Physics B, Vol.17, No.8 & 9, 1217-1222, 2003.- (要約)
- ピロール基のN-置換基末端に糖鎖を有するピロ-ル誘導体1-(6-D-gluconamidohexyl) pyrrole (GHP)を用いて作製したグルコースセンサは, 25℃の環境下における測定では,120日以上のセンサ寿命を示したが,生体内温度にあたる40℃での測定(保存温度も40℃)では,センサ応答の安定性が著しく低下した.これは40℃において酵素固定膜の膨潤及び剥離が著しいことが原因であった.そこで酵素固定膜の膨潤抑制及び電極との密着性·親和性を向上させるため,生体適合性を有し,バイオマテリアルとして用いられているポリジメチルシロキサン(PDS)とナフィオンの両ポリマ-を導入した酵素固定電極を作製した.その結果,40℃で測定及び保存を行った場合においても,電極作製直後から約30日間は安定した応答電流が得られることが確認された.またPDS及びナフィオンを含むGHPの電解重合膜の富血小板血漿吸着試験を行ったところ,優れた生体適合性を有することがわかった.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1142/S0217979203018776
- (文献検索サイトへのリンク)
- ● Summary page in Scopus @ Elsevier: 2-s2.0-0038101512
(DOI: 10.1142/S0217979203018776, Elsevier: Scopus) Mikito Yasuzawa, Hiroyuki Hamada, Keisuke Oga and Yusuke Fuchiwaki :
Design and Construction of Automated Amperometric Immunosensing System,
International Journal of Modern Physics B, Vol.17, No.8&9, 1211-1216, 2003.- (要約)
- 2種類のIgGクラス抗トランスフェリン抗体を用い,トランスフェリンの定量を行うことのできるセンサの作製を行った.これまでの測定では,バッチ法を用いて行っていたため,測定には煩雑な作業が必要であったが,本研究においてはフローシステムを導入したことにより,測定の自動化が可能になり,測定時間も従来の測定に比べ,約1/4の12分間/サンプルで行うことが可能になった.また高価でかつ煩雑な作製手順を要する抗体固定電極を,繰り返し使用(リサイクル)するため,使用後の電極を,4℃の条件下で酸性処理を行ったところ,10回の再利用が可能であることを確認している.また抗原抗体反応により電極表面に結合しているフェロセンの電子授受を効率よく行うため,これまではフェロセニルメチル-3-(ピロール-1-イル)プロピルジメチルアンモニウムブロマイドの電解重合膜を用いていたが,今回より安価なポリピロール膜を使用したが,再現性もよく,高感度な定量測定が可能であった.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1142/S0217979203018764
- (文献検索サイトへのリンク)
- ● Summary page in Scopus @ Elsevier: 2-s2.0-0038101511
(DOI: 10.1142/S0217979203018764, Elsevier: Scopus) Akira Kunugi, Md Abdul Jabbar, Shuichi Naitoh, Mikito Yasuzawa and Hidemitsu Uno :
Introduction of sulfur atoms into trifluoromethylated alkenyl sulfones and chlorides using a reactive sulfur-graphite electrode,
Electrochemistry, Vol.68, No.12, 955-962, 2000.- (文献検索サイトへのリンク)
- ● Summary page in Scopus @ Elsevier: 2-s2.0-0345817125
(Elsevier: Scopus) Mikito Yasuzawa, Shinji Fujii, Akira Kunugi and Tadao Nakaya :
Characterization of glucose sensor prepared with the electropolymerized pyrrole containing a saccharide unit.,
Electrochemistry, Vol.68, No.11, 920-923, 2000.- (要約)
- 酵素の存在下,ピロールやその誘導体の電解酸化重合により,電極表面に酵素を固定する方法は,酵素活性を保持したまま,容易に微小酵素固定電極を作製する方法として興味深い.しかしながら,この方法では酵素は,ただ単にポリピロールマトリックス中に包括的に保持されているため,電極表面に安定に固定されているとは言い難く,センサ寿命の面で改善が必要である.そこで本研究では,糖鎖を有する化合物が酵素と水素結合することに着目し,糖鎖を有するピロール誘導体,1-(3-D-グルコンアミドプロピル)ピロール(GPP) を用い,より安定に酵素が固定された酵素固定電極の作製を試みた.酵素としてはグルコースオキシダーゼを用い,得られた電極のグルコースセンサ特性についても検討を行った.また生体内に存在する電気化学的活性な物質の影響を抑制する効果が報告されている1,2-フェニレンジアミン(PD)の電解重合膜(PPD膜)を導入した電極の作製もあわせて行い,その効果について検討を行った.GPP電極の経過日数と応答電流の関係を調べた結果,作製から4日目に電流値の減少が見られたものの,2週間以上にわたり,安定した応答電流を示した.一般に,電解重合により作製した酵素固定電極は,作製後,数日間は著しい応答電流の変化が見られるが,今回作製した電極が,作製直後から,比較的安定した応答電流を示したのは,GPP膜内に存在する酵素は,ただ単に包括的に固定されているだけでなく,糖鎖と酵素の間で水素結合が形成されることにより,より強固に固定されているためではないかと考えられる.
Properties of glucose sensor based on the immobilization of glucose oxidase in N-substituted polypyrrole film,
Sensors and Actuators B: Chemical, Vol.66, 77-79, 2000.- (要約)
- ピロールやその誘導体を酵素の存在下で電解重合することにより,酵素を電極表面に固定する電解重合法は,酵素を局部的に固定した微小酵素センサを簡単に作製する方法として興味深い.しかしながら,この方法で作製した電極では,酵素は電極表面に形成されたピロールの重合膜に包括的に修飾されているため,十分安定に固定されているとは言えない.そこで本稿では,酵素を電解重合法により局部的に固定し,さらに水溶性カルボジイミド(EDC)で架橋化させることにより,安定した酵素膜を有するセンサの作製を試みた.また内部膜として生体内に存在する電気化学的活性物質の透過抑制に効果があると言われる1,2-フェニレンジアミン(PD)の電解重合膜(PPD膜)を用いた電極も作製した.酵素としてはグルコースオキシダーゼを,電解重合性モノマーとしては,EDCによる酵素との共有結合性を考慮して,ピロールのN-置換基末端にカルボン酸基を有する3-(1-ピロール)プロピオン酸 をそれぞれ用いた.その結果,得られた電極は,グルコース濃度約7mM まで良好な直線関係が見られた.また,経過日数と応答電流の関係を調べた結果,作製後3日間は,応答電流の減少が見られたが,以降約20日間以上にわたり,安定した応答電流を得られた.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1016/S0925-4005(99)00453-0
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1016/S0925-4005(99)00453-0
(DOI: 10.1016/S0925-4005(99)00453-0) Mikito Yasuzawa, Takashi Matsuki, Hikari Mitsui, Akira Kunugi and Tadao Nakaya :
Properties of glucose sensors prepared by the electropolymerization of pyrroles containing phosphatidylcholine (II),
Sensors and Actuators B: Chemical, Vol.66, 25-27, 2000.- (要約)
- 近年,リン脂質の一つであるホスファチジルコリンの極性部を持つポリマーは,優秀な生体適合性(血液適合性)を有することから,バイオマテリアルとして注目されている.一方,ピロール基を有する化合物を酵素の存在下で電解重合を行うと,容易に酵素を局部的に固定した電極が作製できる.そこで我々は以前,N-置換基末端にホスファチジルコリンの極性部を有するピロール誘導体を用い,グルコースオキシダーゼ固定電極の作製したところ,作製から2ヶ月以上に渡り,安定した応答電流を与えることがわかった.しかしながら,生体内に存在する電気化学的活性物質(妨害物質)の応答電流への影響を調べたところ,いずれの電極の場合においても,アスコルビン酸,尿酸の存在が応答電流に大きく影響を与えることがわかった. そこで本研究では妨害物質の影響を抑制する効果が報告されている1, 2-フェニレンジアミンの電解重合膜(PPD膜)やナフィオン膜を導入した酵素固定電極の作製を行い,そのセンサ特性について検討を行った.その結果,PPD膜およびナフィオン膜の導入は,センサ寿命の向上並びに妨害物質の影響の低減に有効であることが分かった.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1016/S0925-4005(99)00452-9
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- ● Search Scopus @ Elsevier (DOI): 10.1016/S0925-4005(99)00452-9
(DOI: 10.1016/S0925-4005(99)00452-9) Mikito Yasuzawa, Masaru Hashimoto, Shinji Fujii, Akira Kunugi and Tadao Nakaya :
Preparation of glucose sensors using the Langmuir-Blodgett technique,
Sensors and Actuators B: Chemical, Vol.65, 241-243, 2000.- (要約)
- Langmuir-Blodgett (LB)法を用いて作製した酵素固定電極は,酵素が脂質単分子膜の中に取り込まれた,生体膜のような構造を持つことが期待され,興味深い.しかしながらこれまでに報告されているLB法を用いた酵素センサでは,酵素が安定に固定されていないことやセンサ応答が遅いなど,またこれらを克服するには煩雑な作業が要求された.本稿では酵素を取り込む膜の強度を高めるため,脂質膜としてリン脂質類似構造を持つポリマーを用い,白金線電極上にグルコースオキシダーゼを固定した電極の作製を試みた.その結果,得られたグルコースセンサは応答が速く,約30日間は安定した応答電流を示すことがわかった.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1016/S0925-4005(99)00454-2
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1016/S0925-4005(99)00454-2
(DOI: 10.1016/S0925-4005(99)00454-2) Mikito Yasuzawa, Shinji Fujii, Akira Kunugi and Tadao Nakaya :
Properties of glucose sensors prepared by the electropolymerization of pyrrole containing a gluconyl group,
Analytical Sciences, Vol.15, No.12, 1175-1176, 1999.- (要約)
- ピロールやその誘導体を酵素の存在下で電解重合することにより,酵素を電極表面に固定する電解重合法は,酵素を局部的に固定した微小酵素センサを簡単に作製する方法として興味深い.しかしながら,この方法で作製した電極では,酵素は電極表面に形成されたピロールの重合膜に包括的に修飾されているため,十分安定に固定されているとは言えない.そのため我々は以前,糖鎖を有するピロール誘導体を用いれば,糖鎖が酵素と水素結合を形成することにより,酵素がより強固に固定された酵素固定電極の作製が期待できると考え,ピロールのN-置換基末端からメチレン鎖を3つ挟み糖鎖を有するピロール誘導体を用い,酵素(グルコースオキシダーゼ)を固定した電極の作製を行った.その結果,グルコースに対して作製直後から約3ヶ月間に渡りセンサ応答を示したが,センサ感度は徐々に減少した.これは,用いたピロール誘導体がピロール環と比較的嵩高い糖鎖との距離が近いため,電解重合膜の伝導度が低く,重合度の高い膜が形成されず,酵素を十分に安定に固定できなかったためだと考えられた.一般にピロールに長いメチレン鎖を置換基として導入することは,ポリマーの伝導度の低下を導くが,ピロール環と嵩高い糖鎖との間隔をメチレン鎖で離すことは,得られたポリマーのピロール環同士が平面構造を形成するのに有利に働くことが予想され,伝導度の向上が期待される.そこで本稿ではピロール環と糖鎖と間隔をメチレン鎖6に広げたピロール誘導体の合成を行い,電解重合法による酵素固定電極の作製およびそのグルコースセンサ特性についての検討を行った.その結果電極作製直後から4ヶ月以上の長期に渡り,感度変化のない,安定したセンサ応答を示した.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.2116/analsci.15.1175
- (文献検索サイトへのリンク)
- ● Summary page in Scopus @ Elsevier: 2-s2.0-0343820076
(DOI: 10.2116/analsci.15.1175, Elsevier: Scopus) Mikito Yasuzawa and Akira Kunugi :
Properties of glucose sensors prepared by the electropolymerization of a positively charged pyrrole derivative,
Electrochemistry Communications, Vol.1, No.10, 459-462, 1999.- (要約)
- ピロール類等の電解重合により酵素固定を行う方法は,操作が容易等種々の特徴を有するが,酵素が遊離しやすい等の欠点が見られた.本研究ではグルコースオキシダーゼ等の酵素が中性環境ではマイナスの帯電していることに着目し,ピロール環のN-置換基末端にプラスチャージを有するピロール誘導体の合成を行い,酵素固定電極の作製に用いた.その結果20日間安定した応答を示すセンサの作成が可能であった.またカチオン交換膜であるナフィオンを予め被覆した後,酵素を固定した電極の作製も行ったが,この場合50日間以上安定した応答を示した.また生体液中に存在する電気化学的活性物質のセンサ応答に対する影響を調べたところ,アスコルビン酸,尿素,フルクトースおよび解熱剤として良く服用されるアセトアミノフェンの影響は見られなかったが,尿酸については無視できる値ではなかった.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1016/S1388-2481(99)00095-8
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1016/S1388-2481(99)00095-8
(DOI: 10.1016/S1388-2481(99)00095-8) Akira Kunugi, Masaru Fujioka, Mikito Yasuzawa, Minoru Inaba and Zempachi Ogumi :
Electroreduction of 2-cyclohexen-1-one on metal-solid polymer electrolyte composite electrode,
Electrochimica Acta, Vol.44, No.4, 653-657, 1998.- (要約)
- 2-シクロヘキセンー1-オンの電解還元における電極材料の影響を種々金属修飾固体高分子電解質電極を用いて行った.固体高分子電解質にはナフィオンとセレミオンを,修飾する金属としては,白金または金を用い,白金や金に更にビスマスや亜鉛を修飾した電極も作製し電解を行った.生成物としてはシクロヘキサノン,2-シクロヘキセンー1-オール,および/またはジケトン(二量体)が得られ,用いる電極の種類によって生成物も異なった.例を挙げると白金修飾ナフィオンにビスマスまたは亜鉛を修飾させた電極を用いた電解では,シクロヘキサノンが選択的に高い電流効率で生成した.また金修飾ナフィオンにビスマスを修飾した電極を用いた電解では,二量体が選択的に得られた.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1016/S0013-4686(98)00177-7
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1016/S0013-4686(98)00177-7
(DOI: 10.1016/S0013-4686(98)00177-7) Akira Kunugi, Mikito Yasuzawa and Hiroshi Matsui :
Electroreductive aromatization of imines and diimines,
Journal of Applied Electrochemistry, Vol.27, No.12, 1390-1393, 1997.- (要約)
- 種々の電極を用いたイミン類およびジイミン類の電解還元によるアミン類の合成を行った.アミン生成物は,電極として水銀<白金<グラッシーカーボン<グラファイトフェルトの順に大きくなった.またグラファイトフェルト表面に亜鉛やビスマスを修飾させることにより,更に収率を向上させることが可能であった.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1023/A:1018429330441
- (文献検索サイトへのリンク)
- ● Summary page in Scopus @ Elsevier: 2-s2.0-0031342810
(DOI: 10.1023/A:1018429330441, Elsevier: Scopus) Mikito Yasuzawa, Kyouhiro Kan, Akira Kunugi, Zempachi Ogumi and Zen-ichiro Takehara :
Electrooxidation of benzyl alcohol on Pt-Nafion composite electrode,
Electrochimica Acta, Vol.40, No.11, 1785-1787, 1995.- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1016/0013-4686(95)00089-W
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1016/0013-4686(95)00089-W
(DOI: 10.1016/0013-4686(95)00089-W) Akira Kunugi, Shinya Mori, Mikito Yasuzawa, H. Uno and K. Sakamoto :
Electrochemical method to vinyl fluorides. Electrochemical cleavarage of 1-fluoro-2-arylvinyl phenyl sulfoxides in acetonitrile,
DENKI KAGAKU, Vol.63, No.5, 433-436, 1995. Mikito Yasuzawa, Akira Kunugi, Minoru Inaba and Zempachi Ogumi :
Electroreduction of acetophenone on Pt-Nafion composite electrode,
DENKI KAGAKU, Vol.62, No.12, 1183-1187, 1994. Tadao Nakaya, Mikito Yasuzawa and Minoru Imoto :
Synthesis and polymerization of 2-{(2-methacryloyloxy)ethyldimethylammonio}ethyl p-substituted phenyl phosphates,
MACROMOLECULAR REPORTS, Vol.A31, 207-215, 1994. Hiroshi Matsui, Akira Kunugi and Mikito Yasuzawa :
The impedance study of the oxidation of formic acid at a platinum electrode,
Electrochimica Acta, Vol.38, No.14, 1899-1901, 1993.- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1016/0013-4686(93)80312-N
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1016/0013-4686(93)80312-N
(DOI: 10.1016/0013-4686(93)80312-N) Mikito Yasuzawa, Nobuyuki Matsushita, Hiromu Satake and Akira Kunugi :
Characterization of N-substituted polypyrrole thin-film electrode having immobilized glucose oxidase,
Sensors and Actuators B: Chemical, Vol.13-14, 665-666, 1993. Akira Kunugi, Kenji Yamane, Mikito Yasuzawa, Hiroshi Matsui, Hidemitsu Uno and Katsuji Sakamoto :
Electrochemical method to vinyl fluorides - I. Cathodic elimination of 1-fluoro-2-arylvinyl phenyl sulphones in acetonitrile,
Electrochimica Acta, Vol.38, No.7, 1037-1041, 1993.- (要約)
- 2-シクロヘキセンー1-オンの電解還元における電極材料の影響を種々金属修飾固体高分子電解質電極を用いて行った.固体高分子電解質にはナフィオンとセレミオンを,修飾する金属としては,白金または金を用い,白金や金に更にビスマスや亜鉛を修飾した電極も作製し電解を行った.生成物としてはシクロヘキサノン,2-シクロヘキセンー1-オール,および/またはジケトン(二量体)が得られ,用いる電極の種類によって生成物も異なった.例を挙げると白金修飾ナフィオンにビスマスまたは亜鉛を修飾させた電極を用いた電解では,シクロヘキサノンが選択的に高い電流効率で生成した.また金修飾ナフィオンにビスマスを修飾した電極を用いた電解では,二量体が選択的に得られた.
Synthesis and Polymerization of 2-{2-(Methacryloyloxy)ethydimethylammonium}ethyl n-Alkyl Phosphate,
Chemistry Express, Vol.7, No.11, 861-864, 1992. Akira Kunugi, Mikito Yasuzawa and Hiroshi Matsui :
Electrochemical carboxylation of b-methylsulphenyl-b-methylsulphonylstyrene in N,N-dimethylformamide containing carbon dioxide,
Electrochimica Acta, Vol.36, No.8, 1341-1344, 1991.- (要約)
- 2-シクロヘキセンー1-オンの電解還元における電極材料の影響を種々金属修飾固体高分子電解質電極を用いて行った.固体高分子電解質にはナフィオンとセレミオンを,修飾する金属としては,白金または金を用い,白金や金に更にビスマスや亜鉛を修飾した電極も作製し電解を行った.生成物としてはシクロヘキサノン,2-シクロヘキセンー1-オール,および/またはジケトン(二量体)が得られ,用いる電極の種類によって生成物も異なった.例を挙げると白金修飾ナフィオンにビスマスまたは亜鉛を修飾させた電極を用いた電解では,シクロヘキサノンが選択的に高い電流効率で生成した.また金修飾ナフィオンにビスマスを修飾した電極を用いた電解では,二量体が選択的に得られた.
Electroreductive desulfurization and carboxylation of a,b-bis(methylsulfonyl)styrene in nonaqueous media,
DENKI KAGAKU, Vol.59, No.1, 64-66, 1991. Akira Kunugi and Mikito Yasuzawa :
Electroreductive carboxylation of 1-methylthio-1-p-tolylsulfonyl-2-arylethenes in N,N-dimethylformamide,
DENKI KAGAKU, Vol.58, No.3, 264-265, 1990. Tadao Nakaya, Mikito Yasuzawa and Minoru Imoto :
Poly(phosphatidylcholine) analogues,
Macromolecules, Vol.22, No.11, 721-726, 1989.- (要約)
- 生体膜の主構成成分であるリン脂質は,膜の強度を保つ物理的な機能に加え,選択透化性等の特異性を有することが知られている.またリン脂質の中でも脳や神経等に多く存在するホスファチジルコリンの極性基を有するポリマーは,生体適合性材料として注目されている.これまでの報告されている研究のほとんどは,ビニルポリマー等の側鎖にホスファチジルコリンの極性基を導入しているものであるが,本報に示したポリマーは,ポリマー主鎖にホスファチジルコリンの極性基を有するものであり,P-Oマイナスと四級アミンのプラスが交互に並ぶ全く新しいポリマーである.重合は2-オキソー1,3,2ージオキサホスホラン環とジメチルアミンの両方を有するモノマーを極性溶媒で加熱することにより,2-オキソー1,3,2ージオキサホスホラン環がジメチルアミンにより開環し,分子間結合を形成して起こる.得られたポリマーは,高分子電解質的挙動を示した.
β,β-ビス(メチルスルホニル)スチレンのアセトニトリル/水銀電極系における電解還元反応,
Chemistry Express, Vol.4, No.3, 189-192, 1989年. Mikito Yasuzawa, Tadao Nakaya and Minoru Imoto :
Polymeric phospholipid analogs. XV. Polyacrylamides containing phosphatidylcholine,
Journal of Macromolecular Science: Part A - Chemistry, Vol.A23, No.8, 963-972, 1986.- (要約)
- 体膜の主構成成分であるリン脂質は,膜の強度を保つ物理的な機能に加え,選択透化性等の特異性を有することが知られている.またリン脂質の中でも脳や神経等に多く存在するホスファチジルコリンの極性基を有するポリマーは,生体適合性材料として注目されている.本報では,ホスファチジルコリンの極性基を有し新規アクリル及びメタクリル系ポリマーの合成を行った.またポリマーに疎水性を増すためにベンゼン環をアミド結合を介して導入した.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1080/00222338608081104
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1080/00222338608081104
(DOI: 10.1080/00222338608081104) Mikito Yasuzawa, Tadao Nakaya and Minoru Imoto :
Polymeric phospholipid analogs (18). Synthesis and properties of vinyl polymers containing both vitamin E and phosphatidylcholine analogous moieties,
Makromol. Chem., Rapid Commun., Vol.6, No.11, 727-731, 1985.- (要約)
- 生体膜の主構成成分であるリン脂質は,膜の強度を保つ物理的な機能に加え,選択透化性等の特異性を有することが知られている.またリン脂質の中でも脳や神経等に多く存在するホスファチジルコリンの極性基を有するポリマーは,生体適合性材料として注目されている.一方,ビタミンEであるαートコフェロールは,体内において抗酸化作用を行うのに加え,様々な薬理活性を示す.本報では,ホスファチジルコリンの極性基とビタミンEが共有結合で結びついたメタクリル酸モノマーの合成を行い,更にそのラジカル重合によるポリマーの合成を行った.得られたポリマーの膜電位を調べたところ,膜が負に帯電していることが分かった.αートコフェロールの代わりにコレステロールを用いたポリマーとでは,正に帯電しており,興味深い結果が得られた.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1002/marc.1985.030061104
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1002/marc.1985.030061104
(DOI: 10.1002/marc.1985.030061104) Mikito Yasuzawa, Tadao Nakaya and Minoru Imoto :
Polymeric phospholipid analogs (17). Synthesis and properties of vinyl polymers containing both cholesterol and phosphatidylcholine analogous moieties,
Makromol. Chem., Rapid Commun., Vol.6, No.11, 721-726, 1985.- (要約)
- 生体膜の主構成成分であるリン脂質は,膜の強度を保つ物理的な機能に加え,選択透化性等の特異性を有することが知られている.またリン脂質の中でも脳や神経等に多く存在するホスファチジルコリンの極性基を有するポリマーは,生体適合性材料として注目されている.本報では,リン脂質と同じく生体膜の主構成成分である中性脂質のコレステロールとホスファチジルコリンの極性基の両方を有するメタクリル酸モノマーの合成並びにそのラジカル重合により得られたポリマーの合成を行い,その特性について調べた.得られたポリマーのキャストフィルムを作成し,膜電位を調べたところ,膜が正に帯電していることが分かった.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1002/marc.1985.030061103
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1002/marc.1985.030061103
(DOI: 10.1002/marc.1985.030061103) - MISC
- 礒合 俊輔, 日裏 健太郎, 丹波 萌, 倉科 昌, 安澤 幹人 :
電解析出法を用いたグルコース オキシターゼ固定電極の作製,
化学センサ, Vol.33, No.Supplement A, 75-77, 2017年.- (要約)
- Glucose oxidase (GOx)-immobilized electrodes were prepared by the combination of electrodeposition and photopolymerization. Methacryloyl choline chloride (NMA) were employed as photo-polymeriable methacrylates and were added in the enzyme- electrdeposition solution, in order to be entrapped in the enzyme film. In order to investigate the enzyme film formation behavior during the electrodeposition process, quartz crystal microbalance (QCM) technique was employed. QCM measurement results indicated that the amount of deposit increased continuously up to around 15 minutes, while the decrease of deposit was observed after that time. The amount of GOx immobilized on the electrode was also measured using Amplex Red Assay Kit and showed that the decrease of deposit was parallel with the decrease of GOx on the electrode. However, the amount of enzyme on the electrode started to increase again after electrodeposition time of 40 minutes. The glucose sensor sensitivity of the obtained electrode showed a good correlation with the amount of enzyme immobilized on the electrode.
体内グルコースモニタリング用低侵襲型センサの作製およびその評価,
化学センサ, Vol.31, No.Supplement B, 7-9, 2015年.- (要約)
- A fine needle type glucose sensor, which has sensing region on the tip of a fine tapered electrode, was prepared using tapered PEEK tube with platinum-iridium alloy wire. Glucose oxidase was immobilized on the surface of Pt-Ir electrode using the combination of electrodeposition and electropolymerization procedures. The obtained sensor showed good response with sufficient linear relationship between response current and glucose concentration. Long-term stability of the obtained electrode was evaluated for 35 days. After initial change of response current for a week, constant response current was obtained for 1 month and approximately 80% of the initial sensor response remained. In vivo measurement evaluation of the electrode was performed using rabbit. Considerable glucose sensor response change due to the trend of glucose concentration was observed.
セルロース分散液を用いた酵素固定膜の作製およびそのセンサへの応用,
化学センサ, Vol.30, No.Supplement B, 130-132, 2014年.- (要約)
- Biorecognition elements, such as enzyme and antibody, were immobilized on Pt-Ir wire electrode by the combination of electrodeposition and photopolymerization. Glucose oxidase was employed as enzyme and glucose sensor properties of obtained GOx-immobilized electrode were investigated. Sensor sensitivity was significantly influenced by the procedure to prepare electrolytic solution for enzyme electrodeposition, which was considered to be due to the difference in enzyme dispersibility in solution. Methacrylates with functional group, such as epoxy and quaternary amine, were also used beside hexyl methacrylate and hexandiol dimethacrylate, in order to introduce interaction between enzyme and entrapping polymer film.
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1520853833872407552
(CiNii: 1520853833872407552) 南川 慶二, 安澤 幹人, 今田 泰嗣, 藤田 眞吾 :
高大院連携化学実験の継続実施による改善と体験イベントへの活用,
大学教育研究ジャーナル, Vol.11, 151-155, 2014年.- (キーワード)
- 高大連携 / 出張講義 / 大学院教育 / 化学実験 / ティーチングアシスタント
- (徳島大学機関リポジトリ)
- ● Metadata: 106346
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1050583647831176448
(徳島大学機関リポジトリ: 106346, CiNii: 1050583647831176448) 日裏 健太郎, 枝川 和明, 渕脇 雄介, 安澤 幹人 :
電解析出法を用いた生体識別素子固定電極の作製及びそのセンサへの応用,
化学センサ, Vol.30, No.Supplement A, 13-15, 2014年.- (要約)
- Biorecognition elements, such as enzyme and antibody, were immobilized on Pt-Ir wire electrode by the combination of electrodeposition and photopolymerization. Glucose oxidase was employed as enzyme and glucose sensor properties of obtained GOx-immobilized electrode were investigated. Sensor sensitivity was significantly influenced by the procedure to prepare electrolytic solution for enzyme electrodeposition, which was considered to be due to the difference in enzyme dispersibility in solution. Methacrylates with functional group, such as epoxy and quaternary amine, were also used beside hexyl methacrylate and hexandiol dimethacrylate, in order to introduce interaction between enzyme and entrapping polymer film.
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1520009407264083584
(CiNii: 1520009407264083584) 安澤 幹人, 李 江, 枝川 和明 :
低侵襲型グルコースセンサの作製及びその評価,
化学センサ, Vol.29, No.Supplement B, 10-12, 2013年. 日裏 健太郎, 枝川 和明, 安澤 幹人 :
電解析出法および光重合法を組み合わせた酵素固定電極の作製,
化学センサ, Vol.29, No.Supplement B, 13-15, 2013年. 南川 慶二, 安澤 幹人, 今田 泰嗣, 藤田 眞吾 :
化学実験出張講義を通した高大院連携教育の試み,
大学教育研究ジャーナル, Vol.10, 89-94, 2013年.- (キーワード)
- 高大連携 / 出張講義 / 大学院教育 / 化学実験 / ティーチングアシスタント
- (徳島大学機関リポジトリ)
- ● Metadata: 105340
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1050302172854543488
(徳島大学機関リポジトリ: 105340, CiNii: 1050302172854543488) 枝川 和明, 安澤 幹人 :
微細針状グルコースセンサを用いた血管内グルコースモニタリング,
化学センサ, Vol.29, No.Supplement A, 93-95, 2013年.- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1520290883812935552
(CiNii: 1520290883812935552) 飯田 泰広, 安澤 幹人, 安川 智之, 田村 真治, 脇田 慎一, 伊野 浩介, 兵頭 健生, 岡崎 慎司 :
学会レポート PRiME 2012,
化学センサ, Vol.28, No.4, 175-181, 2012年.- (要約)
- New fine needle type glucose sensors were fabricated by immobilizing glucose oxidase (GOD) on the surface of the platinum sputtiring film formed on super-elastic Ni-Ti alloy wire. The immobilization of GOD was successfully performed on the platinum sputtiring film by the electropolymerization of 1-(6-D-gluconamidohexyl) pyrrole (GHP) in the presence of GOD. The glucose sensor properties of the obtained electrodes were performed in the phosphate buffer solution (pH 7.4) containing NaCl. Although the response current increased with the increase of glucose concentration of up to 22 mmol dm-3, the linear relationships range was up to 5 mmol dm-3. The response current of the obtained electrode reached to a stable current within 20 seconds.
白金被覆PETフイルム電極の作製およびそのグルコースセンサへの応用,
化学センサ, Vol.2011-B, No.27, 80-82, 2011年.- (要約)
- In order to improve the stability of Pt thin film electrode prepared on the surface of polyethylene terephthalate (PET) film, three types of binder, Nafion, polyethylene imine (PEI) and silica formed from perhydropolysilazane (PHPZ), were introduced on the surface of PET film prior to Pt sputtering. The strength and stability of obtained Pt-coated PET electrodes were evaluated by pencil scratch test and the observation of surface after 40 C water immersion test. By the use of Nafion and PEI, both pencil scratch hardness and stability in water improved compared with that without the binder, while silica did not perform as a useful binder. Glucose oxidase (GOx) was immobilized on the surface of Pt-coated PET electrodes using electrodeposition and electropolymerization technique and their glucose sensor properties were examined. Glucose sensors prepared using Nafion and PEI as binder provided good response to glucose while the background current were somewhat high. Although the glucose sensor prepared using Nafion as binder showed poor response after 20 days of use, the sensor with PEI binder provided clear glucose response with lowered background current.
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1520853832992628352
(CiNii: 1520853832992628352) 松木 均, 後藤 優樹, 玉井 伸岳, 安澤 幹人 :
人工生体膜のソフトナノテクノロジー,
徳島大学大学院ソシオテクノサイエンス研究部研究報告, Vol.55, 25-30, 2010年.- (要約)
- Soft nanotechnology is technology that treats soft and wet materials such as self-assemblysystems in a living body under a relatively moderate condition. We focus our attention on the sizecontrol of liposomes, namely lipid bilayer membranes and performed the soft nanotechnology insizing of liposomes under high pressure. Two high-pressure sizing techniques, a method ofcontinuous pressure relaxation using a phase transition between gel and liquid crystalline phases ofthe bilayer membrane and that of a pressure-induced gel phase using a phase transition betweenbilayer and nonbilayer membranes, were applied to liposomes of distearoylphosphatidylcholine, andthe effects of the both methods were considered. Further, the application of giant liposomescontrolled by high-pressure sizing to microsensor was briefly described.
- (徳島大学機関リポジトリ)
- ● Metadata: 66693
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1050865122808257664
(徳島大学機関リポジトリ: 66693, CiNii: 1050865122808257664) 吉見 靖男, 伊豆 典哉, 板垣 吉晃, 安澤 幹人, 松口 正信, 兵頭 健生, 田村 真治, 日比野 高士 :
学会レポート 第46回化学センサ研究発表会,
化学センサ, Vol.24, No.4, 182-188, 2008年. 安澤 幹人, 枝川 和明, 高岡 宏樹 :
γーポリグルタミン酸を用いた微細針状グルコースセンサの作製,
化学センサ, Vol.2008-B, No.24, 85-87, 2008年.- (要約)
- Long-term stability of glucose oxidase (GOx) immobilized electrode was improved by the introduction of dietary fiber, gamma-polyglutamic acid (PGA) due to the formation of poly-ion complex between positively charged polypyrrole and negatively charged PGA, which stabilized the enzyme immobilized film. The electrode prepared by the electropolymerization of 1-(6-D-gluconamidohexyl)pyrrole in the presence of GOx and PGA showed best performance in both stability and sensitivity. Outer layer film coating of polyurethane provided good response in horse serum measured at 40℃. Although, the influence of electroactive compounds in biological fluid such as ascorbic acid was low, the influence of uric acid to sensor response was unneglectable.
低侵襲針状酵素センサの作製およびその評価,
化学センサ, Vol.2007-B, No.23, 106-108, 2007年.- (要約)
- A unique needle type glucose sensor which can be used by inserting only the tip of the sensor in the sample was fabricated. In order to maintain enough area for enzyme immobilization and platinum electrode surface, a cave with platinum surface was formed at the tip of the sensor. The enzyme glucose oxidase was immobilized on the platinum surface located in the cave by the combination of electrodeposition and electropolymerization of o-phenylenediamine. Amperometric responses of the prepared electrodes to glucose were examined by measuring the electrooxidation current at a potential of 0.60 V (for hydrogen peroxide detection) in 0.1 mol dm-3 phosphate buffer solution (pH 7.4). The obtained sensor showed good response with good linear relationship with glucose concentration up to 24 mmol dm-3, which is actually wider than general sensor with sensing part outside of the electrode. This may due to the effective reproduction of oxygen generated by the electrooxidation of hydrogen peroxide, which all occurred in the cave. The application of this sensor to a low invasive glucose sensor fabrication is highly feasible.
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1520290882789583232
(CiNii: 1520290882789583232) 野本 信一, 力武 浩太郎, 小出 崇志, 安澤 幹人 :
ペルヒドロポリシラザンを用いたタンパク質吸着抑制表面形成技術の開発,
化学センサ, Vol.42, No.22, 13-15, 2006年.- (要約)
- Hydrophilic surface modification was performed on glass and stainless plate using perhydropolysilazane (PZ) and polyethylene glycol (PEG). The water contact angle was lower on the surface prepared using higher molecular weight PEG. Although, the introduction of monoalkoxy PEG to the surface of silica was performed without any matter, dialkoxy PEG did not react with PZ and silica film without PEG was obtained on the surface. Molar ratio of protein adsorption of fibrinogen to albumin (F/A molar ratio), which was adopted as the indicator of biocompatibility, was measured. The F/A molar ratio was lowered by the surface modification of PEG. PEG surface modification contributed to improve the biocompatibility.
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1520853834317810816
(CiNii: 1520853834317810816) 森山 健史, 高岡 宏樹, 安澤 幹人, S. George WILSON :
微細針状マルチチャンネルセンサ作製を目的とした微小領域への選択的酵素固定技術の開発,
化学センサ, Vol.42, No.22, 10-12, 2006年.- (要約)
- In addition to precise localization of enzyme on a minute sensing region, prevention of the enzyme adsorption onto inappropriate electrode surface is essential on the fabrication of multichannel enzyme sensor. Masking of a platinum electrode surface was performed by dipping the electrode in allyl derivatives solution and was removed by applying a potential of 1.50 V (vs. Ag/AgCl). The effect of the introduction of allyl derivatives to prevent enzyme adsorption was evaluated by using electrochemical procedure and optical procedure. Negatively charged allyl sulfonic acid could prevent the adsorption of glucose oxidase significantly, since the pI of GOx is 4.2 and negatively charged at neutral media. Optical procedure provided reliable results than that obtained from electrochemical procedure.
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1520290882288494976
(CiNii: 1520290882288494976) 高岡 宏樹, 森山 健史, 山本 美穂, 安澤 幹人, 今井 信治, Raeann GIFFORD, S. George WILSON :
超弾性合金を芯材に用いた体内埋め込み測定用バイオセンサの作製,
化学センサ, Vol.42, No.22, 7-9, 2006年.- (要約)
- In the development of in vivotype glucose sensor, miniaturization of the sensor size and flexibility is quite importance to reduce damage to the tissue from sensor implantation.Super flexible Ni-Ti alloy wire with a diameter of 100mm was applied as a core material in order to obtain fine and flexible sensor. Gold plating and platinum plating were performed on Ni-Ti wire to obtain sensing region with platinum surface and was applied for glucose sensor. Pt sensing region prepared on Au plated Ni-Ti presented good response to hydrogen peroxide and the applied glucose sensor also showed good response to glucose. Back ground current and current noise were significantly lower than that prepared from Pt sputtering on Ni-Ti wire.
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1520572357402168960
(CiNii: 1520572357402168960) 安澤 幹人, 古川 晋也, 高岡 宏樹, Raeann GIFFORD, S. George WILSON :
インビボ測定用マルチチャンネルセンサの開発,
化学センサ, Vol.41, No.22, 115-117, 2006年.- (要約)
- Glucose/lactate dual-channel needle type biosensor with the total diameter of less than 250 μm was fabricated by the combination of glucose oxidase (GOx) immobilized tube electrode and lactate oxidase (LOx) immobilized wire type electrode. GOx immobilized tube electrode was prepared by the formation of sensing site on Pt-coated polyimide tube and immobilizing GOx by electrodeposition of GOx followed by electropolymerization of o-phenylenediamine. LOx immobilized wire type electrode was also prepared by first enzyme electrodeposition step and then electopolymerization step. Both GOx immobilized tube electrode and LOx immobilized wire type electrode showed good response and showed good linear response up to 15 mmol dm-3 in both 0.1 mol dm-3 phosphate buffer solution (pH 7.4) and in horse serum. No crosstalk was observed when glucose/lactate dual-channel needle type biosensor was tested in 0.1 mol dm-3 phosphate buffer solution (pH 7.4). In vivo measurement in rats with the dual channel sensors is under investigation.
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1520290882391120640
(CiNii: 1520290882391120640) 高岡 宏樹, 安澤 幹人, 清水 利泰, 今井 信治, Raeann GIFFORD, S. George WILSON :
インビボ測定用フレキシブルグルコースセンサの開発,
化学センサ, Vol.41, No.22, 112-114, 2006年.- (要約)
- Important design considerations for in vivo type glucose sensors include miniaturization and flexibility, specificity, biostability, long useable life span, and safety. In the design of the sensor, miniaturization of the sensor is of primary importance. Miniaturization and flexibility of the sensor will help reduce the damage to the tissue from sensor implantation. Sensors fabricated from small diameter platinum (<0.1mm) can be brittle, therefore create a greater risk of breakage. In this study, flexible super-elastic Ni-Ti alloy wire was used as the core material with platinum thin film sputtered on its surface. A comparison of the sensor performance between platinum wire and platinum sputtered Ni-Ti wire is demonstrated. Glucose oxidase immobilization was performed by crosslinking with glutaraldehyde and bovine serum albumin. The sensor was fablicated with an integral Ag /AgCl reference to facilitate in vivo testing. This in vivo type glucose sensor showed remarkable anti-interferent selectivity, moreover with a linearity range extending up to 22.4 mM in the phosphate buffer solution.
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1520290884363888640
(CiNii: 1520290884363888640) 力武 浩太郎, 小出 崇志, 二神 規通, 古川 晋也, 安澤 幹人 :
非特異吸着抑制表面加工技術の開発,
化学センサ, Vol.40, No.21, 43-45, 2005年.- (要約)
- The adaptation of metals surface was performed by the surface reaction of perhydropolysilazane (PZ) in the presence of polyethylene glycol (PEG). Surface hydrophilic property was able to control by the reaction of PEG with PZ and the usage of PEG at various molecular weight. Biocompatibility of platinum treated with PZ and PEG was evaluated by blood platelet adhesion test. The treatment significantly improved the biocompatibility of platinum. Potentiality and utility of new surface processing technique for biocompatibility treatment and nonspecific adsorption inhibition was strongly suggested.
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1520290882321776128
(CiNii: 1520290882321776128) 野本 信一, 高岡 宏樹, 安澤 幹人, 清水 利泰, 今井 信治, Raeann GIFFORD, S. George WILSON :
マイクロ針状グルコースセンサの作製,
化学センサ, Vol.40, No.21, 40-42, 2005年.- (要約)
- Glucose sensors with the diameter of less than 10 um were fabricated using super-flexible Ni-Ti alloy wire as a core material. The 150 um diameter of Ni-Ti alloy wire was reduced by a continuous dipping operation in etching solution. Ni-Ti surface was sputter coated with Pt film. The Pt surface was covered with silica leaving the unetched end bare for electric contact. Silica on the etched tip was removed in order to prepare sensing cavity. Glucose oxidase (GOx) was immobilized on the sensing cavity by the electropolymerization of 1-(6-D-gluconamidohexyl) pyrrole (GHP) in the presence of GOx. Performance characteristics of the fabricated micro glucose sensor were determined in phosphate buffered saline (pH 7.4). The response current increased with the increase of glucose concentration up to 22 mmol dm-3. However, the linear range went up to 11 mmol dm-3. The response time to 90% maximum current for the micro glucose sensor was 20 seconds.
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1520009408727021056
(CiNii: 1520009408727021056) 高岡 宏樹, 森山 健史, 安澤 幹人, 清水 利泰, 今井 信治, Raeann GIFFORD, S. George WILSON :
微細針状グルコースセンサを用いた体内グルコース濃度連続測定評価,
化学センサ, Vol.2005-B, No.21, 34-36, 2005年.- (要約)
- There are various desirable characteristics to consider when designing in vivo type glucose sensors; including miniaturization, specificity, biostability, long useable life span, and safety. Miniaturization of the sensor is an important feature because smaller devices are less invasive, both physically and psychologically. A miniaturized device will excite fewer pain receptors in the skin and will cause less tissue damage, thus less pain and improved performance. However, since miniaturization can lead to easy deformation and breakage of the sensor, it is difficult to fabricate sensors less than 200 μm diameter that retain enough flexibility and strength to insure proper in vivo function. In this study, super-elastic Ni-Ti alloy wire was used as the core material with platinum thin film sputtered on its surface. Glucose oxidase was then immobilized on the platinum surface and functional glucose sensor characteristics were investigated. In vivo measurement with the new flexible glucose sensor was attempted.
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1520853832412803968
(CiNii: 1520853832412803968) Hiroki Takaoka, Toshiyasu Shimizu, Shinji Imai, Shinya Furukawa and Mikito Yasuzawa :
Preparation and properties of enzyme micro sensors,
Chemical Sensors, Vol.2004-B, No.20, 644-645, 2004. Mikito Yasuzawa, Shigeru Inoue, Hiroki Takaoka, Junya Murakami, Toshiyasu Shimizu and Shinji Imai :
In vivo studies of implantable electrochemically fabricated glucose sensors,
Chemical Sensors, Vol.2004-B, No.20, 766-767, 2004. 渕脇 雄介, 力武 浩太郎, 二神 規通, 安澤 幹人 :
抗体固定ビーズを用いた免疫センサの応答再現性評価 (II),
化学センサ, Vol.2003-B, No.19, 64-66, 2003年.- (要約)
- The reproducibility of the antibody-immobilized beads by the acidic antigen-antibody bonds cleavage treatment was performed using an optical procedure. The fluorescein derivative was conjugated to the antigen in order to determine the affinity of the immobilized antibody. The attempt to reduce the nonspecific adsorption of fluorescein-labeled antigen to immobilized antibody was also performed by adding polyethylene glycol and poly(2-methacryloyloxyethyl phosphorylcholine) in the reaction solutions. Although, both polymers were effective to reduce the nonspecific adsorption, either could eliminate the nonspecific adsorption. Fair reproducibility was observed for approximately first five repetition, while the affinity reduction of the immobilized antibody was inevitable by the acidic treatment of pH 3.
微細針状酵素センサの作製及びその評価,
化学センサ, Vol.2003-B, No.19, 91-93, 2003年.- (要約)
- New fine needle type glucose sensors were fabricated by immobilizing glucose oxidase (GOD) on the surface of the platinum sputtiring film formed on super-elastic Ni-Ti alloy wire. The immobilization of GOD was successfully performed on the platinum sputtiring film by the electropolymerization of 1-(6-D-gluconamidohexyl) pyrrole (GHP) in the presence of GOD. The glucose sensor properties of the obtained electrodes were performed in the phosphate buffer solution (pH 7.4) containing NaCl. Although the response current increased with the increase of glucose concentration of up to 22 mmol dm-3, the linear relationships range was up to 5 mmol dm-3. The response current of the obtained electrode reached to a stable current within 20 seconds.
微細針状バイオセンサの作製,
化学センサ, Vol.2003-A, No.19, 4-6, 2003年.- (要約)
- New needle type glucose oxidase immobilized glucose sensors were prepared by the electropolymerization of 1-(6-D-gluconamidohexyl) pyrrole (GHP) on the platinum wire electrode precoated with the solution of GHP, polydimethylsiloxane, and Nafion. In vitro measurement was performed in the phosphate buffer solution (pH 7.4) containing NaCl and bovine serum at 40C. The response current obtained in bovine serum was similar with that in phosphate buffer solution. This indicated that the sensor itself have excellent biocompatibility and the adsorption of protein was hardly prevented. Therefore, the outer coating of biocompatible film such as polyurethane, was not essential. In vivo measurement was performed using rats under gas anesthesia of isoflurane. The sensor was implanted in subcutaneous tissue. After the intraperitoneal injection of glucose (30% solution, 1.0 g kg-1 body weight), the sensor response increased and behaved good agreement with the blood glucose level measured in vitro ith glucose meter.
抗体固定ビーズを用いた免疫センサの光学測定法による安定性評価,
化学センサ, Vol.2002-B, No.18, 64-66, 2002年.- (要約)
- The stability of the antibody-immobilized beads packed column for immunosensor application was evaluated using an optical procedure. Agarose resin and glass beads were employed for the immobilization of the antibody and the antigen was labeled with fluorescein in order to determine the affinity of the immobilized antibody by fluorescent measurement. Luteininzing hormone (LH) and its IgG class monoclonal antibody (anti-LH) were employed. The stability of the anti-LH column was evaluated by repeating the acidic treatment (pH 3) that will reproduce the column by cleaving the antigen-antibody bond formed on the surface of the beads. Although, the affinity of the antibody immobilized column reduced slightly for the first five times, relatively good reproducible affinity was observed for more than ten repetitive measurements.
ポリピロール/オルガノポリシロキサン複合膜を用いたグルコ-スセンサの作製,
化学センサ, Vol.34, No.18, 136-138, 2002年.- (要約)
- New glucose oxidase immobilized glucose sensors were prepared by the electropolymerization of 1-(6-D-gluconamidohexyl) pyrrole (GHP) and 6-(1-pyrrolyl)hexylphosphatidylcholine (PPC) on the platinum wire electrode precoated with the solution of pyrrole derivative (GHP and PPC) and polydimethylsiloxane. Although, the response of the electrode prepared from PPC was satisfactory obtained, no response was observed from the electrode of GHP. By the addition of Nafion into the precoating solution, the improvement of sensor sensitivity occurred and the electrode prepared from GHP also showed clear sensor response. Moreover, the introduction of Nafion was effective to improve the long-term stability of the enzyme immobilized electrodes. The electrode prepared from both Nafion and GHP performed excellent long-term stability. Relatively constant response current was obtained over 30 days in pH 7.4 phosphate buffer solution under the condition of 40 C measurement and storage temperatures.
- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1520290883356228352
(CiNii: 1520290883356228352) 濱田 浩幸, 大賀 敬介, 安澤 幹人 :
抗原抗体反応を用いたリアクター・ディテクター分離型センサの開発(II),
化学センサ, Vol.2002-A, No.18, 181-183, 2002年.- (要約)
- Reactor/detector devided antibody sensing system was developed using two monoclonal IgG class anti-rat transferrin antibodies (15C2H3 and 22A06D2). Agarose resin containing hydrazide was applied to immobilize 22A06D2 and ferrocene polymer was labeled to 15C2H3. After the sandwich formation (agarose resin=antibody-antigen-antibody=ferrocene polymer) was constructed proportionally to the transferrin concentration, the reactor was treated with acidic solution and the antibody=ferrocene polymer was released from the the reactor in order to be measured amperometrically at the detector. The relationship between the transferrin concentration and sensor response was measured in the range of 0 to 300 ng cm-3 and relatively good calibration curve was obtained. The antibody immobilized agarose resin was able to reuse at least 5 times.
Synthesis of N-Methyl-D-Glucamine Modified Chitosan Nanofibers for Boron Adsorption,
The 3rd International Conference on Nanomaterials and Advanced CompositesProceedings of NAC 2022,Springer Proceedings in Physics, Vol.298, No.chapter 4, 31-35, 2023.- (徳島大学機関リポジトリ)
- ● Metadata: 119155
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1007/978-981-99-7153-4_4
- (文献検索サイトへのリンク)
- ● Summary page in Scopus @ Elsevier: 2-s2.0-85178519943
(徳島大学機関リポジトリ: 119155, DOI: 10.1007/978-981-99-7153-4_4, Elsevier: Scopus) Yusuke Fuchiwaki and Mikito Yasuzawa :
Immunosensor Accuracy is Improved by Coating Beads with Poly-2-[3-(Methacryloylamino)Propylammonio]Ethyl 3-Aminopropyl Phosphate,
Analytical Letters, Vol.45, 262-271, 2012.- (要約)
- Poly-2-[3-(methacryloylamino)propylammonio]ethyl 3-aminopropyl phosphate (poly-3MAm3AP) is a polymer that contains phosphorylcholine groups which can attract water to form a water layer, and amino groups which can be used for the covalent attachment of receptors such as anti-LH (Luteinizing hormone) antibody and LH antigen. Poly-3MAm3AP was synthesized with the anticipation that it would aid the recognition of a large number of analytes and eliminate nonspecific adsorption. Poly-3MAm3AP was coated on beads and served as an antigen-antibody reaction interface. The specificity of this surface was evaluated using surface plasmon resonance (SPR) by comparing responses to specific anti-LH antibody and nonspecific anti-hemoglobin antibody. Poly-3MAm3AP did not adsorb nonspecific antibody due to the presence of free water associated with the phosphorylcholine moiety. An immunosensor system was fabricated by combining poly-3MAm3AP-coated beads containing immobilized anti-LH antibody with an optical detector. Poly-3MAm3AP not only reduced nonspecific adsorption, but also increased the amount of specific antibody-antigen interaction. These favorable characteristics are due to an increased amount of immobilized receptor, and an increased amount of space for antigen-antibody interaction arising from electrostatic repulsion within the poly-3MAm3AP electrolyte.
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1080/00032719.2011.633180
- (文献検索サイトへのリンク)
- ● Search Scopus @ Elsevier (DOI): 10.1080/00032719.2011.633180
(DOI: 10.1080/00032719.2011.633180) Teruhiko Matsubara, Yuko Hiura, Osamu Kawahito, Mikito Yasuzawa and Katsuhiro Kawashiro :
Selection of novel structural zinc sites from a random peptide library,
FEBS Letters, Vol.555, No.2, 317-321, 2003.- (要約)
- 亜鉛(II)イオンは2 - 3個のアミノ酸残基に結合し,タンパク質の構造を安定化させたり,酵素の活性中心を形成することができる.タンパク質中の亜鉛(II)イオンの結合サイトを同定するために,ファージディスプレイ法を用いて,亜鉛(II)イオンと12量体のランダムペプチドとの結合特異性の探索を行った.2つのアミノ酸配列が明らかにされ,これらは天然に存在する亜鉛(II)含有酵素やフェレドキシンの部分的なアミノ酸配列と一致することがわかった.
- (キーワード)
- Structural zinc / Random peptide library / Metalloenzyme / Phage display system / Sequence homology
- (出版サイトへのリンク)
- ● Publication site (DOI): 10.1016/S0014-5793(03)01266-3
- (文献検索サイトへのリンク)
- ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 14644435
- ● Search Scopus @ Elsevier (PMID): 14644435
- ● Search Scopus @ Elsevier (DOI): 10.1016/S0014-5793(03)01266-3
(DOI: 10.1016/S0014-5793(03)01266-3, PubMed: 14644435)
- 総説・解説
- 安澤 幹人 :
特集(1):臨床検査の次世代分析・試薬の開発, --- 血糖モニタリング用体内埋め込み型バイオセンサの開発 ---,
医療と検査機器・試薬, Vol.39, No.5, 466-469, 2016年10月. 安澤 幹人 :
特集 医療診断と分析化学 「血糖値測定」,
ぶんせき, No.10, 533-538, 2010年10月.- (要約)
- 食生活,運動習慣等の生活習慣の変化や,高齢化の進展に伴い,糖尿病患者は増加の一途をたどり,その予防と治療における戦略はまさに国家的課題となっている.糖尿病は早期からの介入が予後に大きく影響する疾患であることから,本年5月,岡山市で開催された第53回日本糖尿病学会年次学術集会において,糖尿病の早期発見,早期診断を大きな狙いとする新しい診断基準が発表され,本年7月1日より施行された1) .また,昨年10月には,厳格な血糖コントロールに有用とされる持続血糖モニタリングシステム(CGMS)「メドトロニック ミニメド CGMS-Gold」(日本メドトロニック社)が初めて薬事承認を取得する等,今,日本の糖尿病診療は大きく変わろうとしている.そこで本稿では,糖尿病患者の診断および血糖コントロールに用いられている様々な検査法並びにその留意点について紹介する.
体内埋込型バイオセンサ,
マテリアルインテグレーション, Vol.21, No.5,6, 329-334, 2008年5月.- (要約)
- Real-time monitoring of biological compounds (analytes) in biological media may provide extremely useful information for the treatment and the health care of diseases. Blood glucose (BG) monitoring for diabetics is a good illustration, since many of the diabetics need to control the BG level by insulin treatment in order to prevent serious complications by high BG (hyperglycemia) and coma by low BG (hypoglycemia). This article deals with the design, function and evaluation of the implantable in vivo type biosensors, especially glucose sensors for diabetes treatment. Important design considerations for in vivo type glucose sensors include miniaturization and flexibility, specificity, biostability, long usable life span, and safety. Techniques of overcoming the required design and the procedure to evaluate the biosensor were introduced.
化学センサ2006 ナノ化学センサ特集, --- ナノワイヤーを用いたバイオセンサ ---,
化学センサ, Vol.23, No.4, 128-131, 2007年12月.- (文献検索サイトへのリンク)
- ● CiNii @ 国立情報学研究所 (CRID): 1520010379910929536
(CiNii: 1520010379910929536) 安澤 幹人 :
マッハ·ツェンダ型干渉計MZIを用いたセンサーの高感度化,
ぶんせき, Vol.16, No.3, 155-156, 2003年3月.- (要約)
- 近年,高感度測定を必要とする環境ホルモン等の検出のため,表面プラズモン共鳴(SPR)法等,様々なトランスデューサーを用いたセンサーが注目されている.まだ報告例は少ないが,マッハ·ツェンダ型干渉計(MZI)を用いるセンサーは原理的にSPR法以上の高感度化が可能であり,マルチチャンネル化も容易であることから興味深い.本稿ではMZIの原理並びに高感度化,測定器全体の小型化,マルチチャンネル化や量産化による低コスト化等について紹介している.
電解重合法によるグルコースセンサの作製,
化学センサ, Vol.16, No.4, 157-163, 2000年12月.- (要約)
- 電解重合法を用いた酵素固定電極の作製は,酵素を通電させた局所に固定できることから,微小酵素センサの作製が容易であり,また酵素を包括的に固定しているため,固定操作による酵素の活性低下を抑制できる.しかしながら共有結合に比べ,酵素が十分に安定に固定されておらず,長期安定性が劣るという欠点を有していた.本稿では,長期安定性に優れた酵素固定電極の作製を,電解重合法を用いて行う試みについて総説する.特に優れた長期安定性を必要とする生体内埋込型グルコースセンサの開発に向けた研究を中心に記述する.
- 講演・発表
- Mikito Yasuzawa, Sato Yusuke, KIDO Takanari, Zhao Yumeng, Masashi Kurashina, Masao Nagase, Tomoyuki Ueki and Atsushi Tabata :
Preparation of Platinum Nanoelectrodes Using Tapered Tungsten Probes and Their Application to a Single Cell Measurement,
PRiME 2024 (Pacific rim meeting on electrochemisty and solid state science 2024) , Hawaii, M02-4340, Honolulu, Oct. 2024.- (要約)
- Platinum nanoelectrodes, which the electroactive region is located on the tip, were prepared in two steps. First, an insulating film was formed on the tapered tungsten probe by electrodeposition coating using the cationic electrodeposition paint, and then platinum nanopillars with a diameter of about 200 nm were formed on the tip using Focused-Ion-Beam Chemical-Vapor-Deposition (FIB-CVD). The conditions for forming an insulating film on tungsten surface with low thickness and excellent insulation properties were investigated and were evaluated by electrochemical measurements and SEM observations, and an appropriate insulating film was successfully produced. After the formation of a platinum pillar on the tip of an insulating film-coated tungsten probe, a platinum nanoelectrode was obtained and confirmed to function as an electrode. Using automatic micro manipulation system, repeated insertion of platinum nanoelectrode into HeLa cell was attempted. The results showed that the insertion of platinum nanoelectrodes into HeLa cells appeared to be successful.
Investigation of the adhesion of liquid phase exfoliated graphene to surface modified substrates,
International Conference on Advanced Materials Development and Performance 2024 (AMDP 2024), IE36, Tokushima, Sep. 2024.- (要約)
- Graphene, with its excellent electrical and mechanical properties, is expected to be applied in various fields. Liquid-phase exfoliation is a method to produce graphene with a small area but few defects. Coating the surface of the substrate with such graphene is critical for using the graphene as an electronic material. Understanding the adhesion behavior of liquid-phase exfoliated graphene to solid surfaces is essential for controlling its arrangement on substrates. In this study, we investigated how modifying substrate surfaces affects the adhesion of liquid-phase exfoliated graphene. The graphene dispersion was prepared as follows, referring to a previous report.[1] 0.1 g of kish graphite, 2.0 g of sodium dodecylbenzenesulfonate, 2.0 g of sodium chloride, and 100 mL of water were mixed, heated to reflux for 48 hours, and dried under reduced pressure. This mixture was added to ethanol and then sonicated for 3 hours. The dispersion was collected by filtering with a membrane filter (pore size: 0.45 µm), washed with water, and the particles on the filter were dispersed by sonication in water. The supernatant, which was allowed to stand for at least 7 days, was used as the liquid phase exfoliated graphene dispersion. As surface-modified substrates, gold-sputtered silicon wafers were immersed in ethanol solutions of five thiols: 6-amino-1-hexanethiol hydrochloride (AHT), 1-octadecanethiol (ODT), 10-carboxy-1-decanethiol (CDT), 4-aminobenzenethiol (ABT), benzenethiol (BT). The prepared substrates were immediately immersed in liquid phase exfoliated graphene dispersion overnight.The liquid-phase exfoliated graphene was measured by atomic force microscopy (AFM) to be about 1.5-6 nm thick. Considering that the thickness of the graphene itself is 0.3 nm, the dispersion consisted of graphene covered with dodecylbenzenesulfonate (DBS) ions on its surface, and several layers were stacked. Adhered liquid-phase exfoliated graphene was observed by AFM on substrates modified with AHT, ABT, and BT, but not on the other substrates. These results suggest that the adhesion of graphene on the substrate was due to the electrostatic interaction between the terminal amino group of the modified thiol and the sulfonic acid group of the DBS ion, and the π-π interaction between the benzene ring of the modified thiol and the benzene ring of the DBS ion. This result is expected to lead to the control of graphene alignment on substrates.[1] L. Niu et al., Nanoscale, 5(16), 7202-7208, 2013.
Investigation of Insulating Film Formation Method for Fabrication of Pt Nanoelectrodes for Intracellular Measurement,
International Conference on Advanced Materials Development and Performance 2024 (AMDP 2024), PE68, Tokushima, Sep. 2024.- (要約)
- Establishing an electrochemical measurement method to analyze single cells would be useful for understanding and elucidating cell functions and mechanisms, while there is no electrochemical measurement system with high practical utility. One factor is that electrodes with an outer diameter of 200 nm or less are desirable to eliminate the effects of damage caused by the manipulation of electrode insertion into cells, but the fabrication technology for such devices is very limited. Recently, we are interested in microelectrode fabrication using the Focused-Ion-Beam Chemical-Vapor-Deposition (FIB-CVD) method, since it can provide nanopillar with an outer diameter of several hundred nm with controlled length. In this study, platinum nanoelectrodes, which the electroactive region is located on the tip, were prepared in three steps. Firstly, diamond-like carbon (DLC) nanopillar was formed on the tip of tapered tungsten probe using FIB-CVD. Secondary, an insulating film was formed on the tapered tungsten probe and DLC nanopillar by electrodeposition coating using the cationic electrodeposition paint ELECOAT TFY and baking. Finally, platinum nanopillar with a diameter of about 200 nm was formed on the tip of insulating film coated-DLC nanopillar using FIB-CVD. The conditions for forming an insulating film on tungsten surface with low thickness and excellent insulation properties were investigated and were evaluated by electrochemical measurements and SEM observations. It was found that a thin insulating film was successfully produced by placing the electrodeposition container in an ultrasonic cleaner and during the electrodeposition. After the formation of a platinum pillar on the tip of an insulating film-coated tungsten probe, a platinum nanoelectrode was obtained and confirmed to function as an electrode. Using automatic micro manipulation system, repeated insertion of platinum nanoelectrode into HeLa cell was attempted. References 1) S. Han et al., Biochem Biophys. Res. Commun, 2005, 332(3), 633-639
Synthesis of copper hydroxide nanosheet-conjugated Au/Pt nanoparticles aimed for electrode modification,
International Conference on Advanced Materials Development and Performance 2024 (AMDP 2024), PE67, Tokushima, Sep. 2024.- (要約)
- The increase in atmospheric CO2 concentration is a globally important issue as it is considered to have an impact on climate change. Electrochemical reduction of CO2 to other useful compounds is one way to reduce CO2 amount. CO2 reduction is the aim of this study. First is to synthesize a suitable material for electrode. Here, we introduce a possible catalytic material, copper hydroxide nanosheet. Copper hydroxide is a very well-known material that has some potential for providing good electrochemistry ability, possibly can provide good activation area in electrochemistry. Besides, the advantage of using copper hydroxide for electrode material is that it can produce methane or ethane, which is a useful by-product on renewable energy. This can make hydroxide nanosheet a potential non-enzymatic electrode. After ion exchange of dodecylbenzenesulfonate, the crystal structure will be analyzed by XRD, to define the difference before and after ion exchange. On the other hand, Au/Pt nanoparticles bimetallic nanoparticle also had been synthesized, the advantage of the nanoparticles is it also provides wide catalytic area, so this can theoretically provide good effect on the catalytic process of electrode. So far, we have two kinds of potential nanomaterial to conduct electrochemistry, and we consider the possibility to connect these two materials to provide better electrochemistry ability.If we can conjugate these two materials together, we can possibly provide better ability on electrochemistry. Therefore, this research will be focus on the conjugation of two materials, the conjugation compound will be 3-mercapto-1-propanesulfonic acid sodium salt (MPS), which provide sulfonate and thiol functional groups bonding between copper hydroxide nanosheet and Au/Pt nanoparticles, MPS has found and shown affinity in the previous research, and sulfonate bonding in the compound may conjugate to copper hydroxide, so it was chosen to be the intermediate compound to conjugate both materials. The experiment has tried some different methods to conjugate. Different solvent dispersion methods and different mixing methods.
Glucose Oxidation Using Electrode Modified with Nickel Hydroxide Nanosheets,
International Conference on Advanced Materials Development and Performance 2024 (AMDP 2024), PE66, Tokushima, Sep. 2024.- (要約)
- Quantitative analysis of glucose is valuable in many fields, and the development of non-enzymatic glucose oxidation catalysts that do not use enzymes is highly anticipated to facilitate measurements under conditions not possible with enzymes.[1] Various metals are used as catalysts, and several examples of glucose oxidation using nanostructured nickel compounds with high electrocatalytic activity have been reported.[2] Because differences in nanostructure and composition are expected to improve catalytic performance, in this work, we synthesized nickel hydroxide nanosheets and investigated their electrochemical glucose oxidation. Nickel hydroxide nanosheets were synthesized according to a previous report.[3] A nickel acetate tetrahydrate was mixed with an ethanol-water solution and refluxed. The resulting layered nickel basic acetate was collected by centrifuge and was added to an aqueous solution of sodium dodecyl benzenesulfonate to increase the interlayer distance by ion exchange. The resulting layered nickel hydroxides were exfoliated by ultrasonication in 1-butanol and left for over a week to obtain a nanosheet dispersion. The working electrode was prepared as follows. The supernatant of the nanosheet dispersion was mixed with Ketjen black, and the mixture was concentrated under reduced pressure. Nafion or cellulose nanofibers were mixed as binder and drop cast on a φ3 mm glassy carbon (GC) electrode and dried. The electrochemical measurements of the working electrode were carried out in 0.1 M NaOH solution in a standard one-compartment cell. The cyclic voltammograms of the nanosheet-coated electrode showed an oxidation current peak caused by the oxidation of glucose at +0.6V vs. Ag/AgCl. Amperometry was measured at +0.6V vs. Ag/AgCl with continuous addition of glucose solution. The current of the nanosheet-coated electrode increased stepwise with the addition of the glucose solution. The catalytic current was almost proportional to the glucose concentration in the range of 0.09 to 1.69 mM. In the linear range, the sensitivity was 5.25 mA mM¹ cm² as determined from the slope. This value is comparable to other glucose electro-oxidation electrodes using nickel. This work demonstrated that glucose oxidation is possible using nickel hydroxide nanosheet-modified electrodes.[1] S. Y. Tee et al., Mater. Sci. Eng. C, 70, 1018-1030, 2017. [2] E. M. Almutairi et al., Arab. J. Chem., 15(1), 103467, 2022.[3] M. Kurashina et al., Int. J. Mod. Phys. B, 24(15n16), 2291-2296, 2010.
Synthesis of insoluble beads of glycosylated chitosan nanofibers for boron adsorption,
International Conference on Advanced Materials Development and Performance 2024 (AMDP 2024), PE65, Tokushima, Sep. 2024.- (要約)
- Boric acid is widely used in the glass industry and detergents however high concentrations of it are toxic to living organisms, so recovery technologies have been developed. Boron adsorbents, such as Amberlite IRA 743, are synthetic polymers in the main chain with ortho-polyol functional groups in the side chains. In order to reduce the environmental impact of the adsorbents, it is expected that the main chains will be converted to naturally degradable material. In our laboratory, we have developed efficient boron adsorbents based on biodegradable chitosan or chitosan nanofibers.[1, 2] In view of their industrial use, this study investigated the effect of material bead size and insolubilization on boron adsorption.The chitosan nanofiber (Sugino Machine, 2 wt%) was mixed with D-glucono-1,5-lactone and heated to reflux for 24 hours and the reaction product was concentrated under vacuum. The resulting viscous solution was dropped through a 1.75 mm diameter hole into a 1 M NaOH solution to obtain beads A with a diameter of 3 mm. Apart from that, ethylene glycol diglycidyl ether (EGDE) was mixed with the viscous solution and dropped through holes of 1.75 and 0.3 mm diameter into 1 M NaOH solution and heated at 60 °C for 24 hours to obtain beads B and C of 3 and 2.3 mm diameter, respectively. In the boron adsorption experiment, these beads were put into sodium tetraborate decahydrate solutions with different concentrations (10-400 ppm as boron) separably and shaken at 25 °C. The adsorption amount of boron was calculated from the difference of concentrations between before and after adsorption. At 24 hours reaction time, the adsorption amount of each adsorbent followed the Langmuir adsorption isotherm well. The theoretical maximum adsorption capacity of beads A, B, C, and Amberlite IRA743 were 14.1, 3.7, 4.1, and 5.6 mg g-1, respectively. Beads B and C are insoluble in HCl due to cross-linking reaction by EGDE, but the amount of adsorption decreased from A. The time to reach 90% saturation adsorption was 11 hours for bead A and 5 hours for bead C, suggesting the effect of small bead size. [1] Ho Hong Quyen, Doctoral thesis, Tokushima University, 2019. [2] M Kurashina et al., Mod. Phys. Lett. B, 36(16), 2242001, 2022.
Preparation of zwitterionic polymer brush surface using optical ATRP method and its inhibitory effect on protein adsorption,
International Conference on Advanced Materials Development and Performance 2024 (AMDP 2024), PE59, Tokushima, Sep. 2024.- (要約)
- Medical devices that are implanted in the body are subject to adsorption reactions of various components, such as proteins and blood cells, by the body's immune defense system. Therefore, it is essential for medical devices that come into contact with bodily fluids to have a surface that inhibits the adsorption of proteins such as fibrinogen, which occurs in the early stages of the immune response. For this purpose, materials with the ability to retain water are considered useful, and polymers such as sulfobetaine methacrylate (SBMA) and phosphorylcholine methacrylate (MPC), which are zwitterionic polymers, are used [1]. On the other hand, the surface-initiated atom transfer radical polymerization (SI-ATRP) method is interesting because it can form dense polymer brushes (PB) on the substrate surface, and furthermore, photo-ATRP, in which the catalyst is regenerated by UV irradiation, can be fabricated in a simple environment because it proceeds even in the presence of oxygen [2]. In this study, zwitterionic PB was prepared on the substrate surface using Photo-ATRP. SBMA and methacrylate 2-(methacryloyloxy)ethyl choline hydrogen phosphate (MCHP), a novel phosphobetaine methacrylate in which the polar groups of MPC is reversed, were used as zwitterionic monomers. Quartz crystal with SiO2 surface (QCM-SiO2) was used as substrate and fibrinogen adsorption behavior was evaluated using the flow quartz crystal microbalance system. Successful PB modification of SBMA and MCHP on QCM-SiO2 were confirmed by XPS. PBS containing fibrinogen was flowed through the system and the change in mass per unit area of the modified surface was measured. The unmodified SiO2 cell adsorbed 240 ng/cm2, while the SBMA-PB-modified surface adsorbed 118 ng/cm2 and the MCHP-PB-modified surface 20 ng/cm2. Thus, protein adsorption was significantly inhibited by both PB modifications, but the inhibitory effect of MCHP-PB modification was superior to that of SBMA-PB modification. [1] S. Nishimura et al., Bull. Chem. Soc. Jpn. 96, 1052 (2023) [2] W.-Q. Yan et al., Macromolecules 53, 8, 2801 (2020)
The in vitro evaluations of photo-curing 2-(methacryloyloxy)ethyl choline hydrogen phosphate bio-printing scaffold,
International Conference on Advanced Materials Development and Performance 2024 (AMDP 2024), PE58, Tokushima, Sep. 2024.- (要約)
- Patients who require tooth extraction due to trauma, severe periodontal disease, or caries often have the bone defect repaired before receiving future restorations or dental implants. However, such procedures frequently need the use of bone graft powder and/or other materials to promote bone cell proliferation and prevent epithelial cells from migrating prematurely into the defect, putting physicians' skills and techniques to the test. Medical imaging and bioprinting technologies enable the customization of bone scaffolds prior to surgery, which is anticipated to reduce the surgery time and help with estimating the quantity of implant material necessary. 2-methacryloyloxyethyl phosphorylcholine (MPC) is a biocompatible phosphocholine structure with minimal cytotoxicity. Based on the abovementioned features, we further modified its structures to synthesize a novel chemical, i.e., 2-(methacryloyloxy)ethyl choline hydrogen phosphate (MCHP), which phosphocholine structure is translocated, allowing for a wider range of uses. In this study, we combined this material with calcium triphosphate and a photoinitiator to produce a photocurable bioink. In vitro investigations using various bioinks with varying formula ratios revealed that this material is also showing biocompatible and has no significant cytotoxic properties toward cell lines. It also demonstrated a plausible microenvironment for cultured osteoblasts (OB) to differentiation growth, indicating promise for bone regeneration and therapeutic uses in patients with bone abnormalities in the future.
Introducing Biocompatibility into Polypropylene Implant Devices Using 2-(Methacryloyloxy)ethyl Choline Hydrogen Phosphate Copolymers,
International Conference on Advanced Materials Development and Performance 2024 (AMDP 2024), PE57, Tokushima, Sep. 2024.- (要約)
- To improve the biocompatibility of hydrocarbon-based implanted materials, we conducted a study using a novel zwitterionic copolymer to modify the surface of polypropylene (PP) substrates. This modification aimed to decrease protein adsorption, a crucial initial phase of physiological reactions that significantly influences subsequent biological responses. 2-methacryloyloxyethyl phosphorylcholine (MPC) is widely used for medical device surface modification to prevent protein adsorption and platelet adhesion. In our previous research, we have synthesized 2-(methacryloyloxy)ethyl choline hydrogen phosphate (MCHP), in which the order of polar groups is reversed from that of MPC, and applied them to material surface modification. Unlike MPC, MCHP-modified surfaces maintained higher hydrophilicity even in acidic environments. Earlier studies demonstrated that block copolymers with controlled chain orientation, consisting of 70% n-butyl methacrylate (BMA) and 30% MPC units, provided water insoluble copolymers with excellent blood compatibility. To optimize the biocompatibility and stability of MCHP, we synthesized di-block copolymers with varying ratios of BMA and MCHP units and investigated the optimal synthesis conditions. In this study, MCHP and BMA block polymers were synthesized using the RAFT polymerization method. By controlling the polymerization time, we adjusted the chain lengths of MCHP and BMA and determined the monomer ratios in the polymers through molecular weight measurements. These block polymers were then used to modify PP substrates via hydrophobic interactions, and their modification stability and biocompatibility were evaluated. The experimental results revealed that a block polymer with a MCHP to BMA ratio of 2:8 provided high stability and biocompatibility on the modified surface. Compared to the optimal 3:7 ratio for MPC and BMA block polymers, MCHP required a longer hydrophobic chain to maintain stability due to its higher hydrophilicity. Nevertheless, the MCHP-modified surface retained biocompatibility with a shorter zwitterionic chain. In summary, our study demonstrates that MCHP-based block copolymers modification can effectively introduce the biocompatibility of PP substrates, providing a promising approach for improving the performance of implanted materials.
Synthesizing composite materials using zwitterionic polymers and tricalcium phosphate,
International Conference on Advanced Materials Development and Performance 2024 (AMDP 2024), PE56, Tokushima, Sep. 2024.- (要約)
- As the population ages, bone-related diseases such as osteoporosis, bone cancer, and bone tumors are rapidly increasing. This has led to the current need for bone replacement and bone regeneration [1]. Bone is a multiphase material made of collagen matrix and mineral crystals. The collagen matrix provides toughness, while the mineral crystals give bone its rigidity [2]. Therefore, a composite material combining organic and inorganic components was considered to fill bone defects. Calcium phosphate (CaP) biomaterials are widely used as an alternative to autogenous bone grafts [3]. On the other hand, the zwitterionic methacrylate 2-(methacryloyloxy)ethyl choline hydrogen phosphate (MCHP) has high biocompatibility and is thought to have a high affinity with CaP-based materials due to its terminal phosphate group. In addition, as MCHP is a methacrylate, light irradiation of the mixtures of MCHP and CaP are expected to allow for the formation of moldings to compensate for bone defects. In this study, a mixture of tricalcium phosphate (TCP) and MCHP, which is considered to be easily absorbed by bone among Caps, was prepared. MCHP and TCP were mixed in Milli-Q water in the weight ratio MCHP : TCP = 3 : 7, 4 : 6, 5 : 5, and a photoinitiator was added to obtain a paste-like mixture. The mixture was placed in a mold and photo-irradiated with a xenon flashlamp to obtain a solid product. Each sample was named MCP-TCP37, MCP-TCP46, and MCP-TCP55 according to its weight ratio.All of the composite solids obtained absorbed water and swelled. The magnitude of swelling was in the order of MCP-TCP37, MCP-TCP46, and MCP-TCP55MCP, indicating that the higher the percentage of MCP, the greater the swelling.The MCHP elution from the composite solids and the physical properties of the composite solids were also investigated.Keywords: Composite materials; Scaffold; Zwitterionic polymers; Tricalcium phosphate. [1] M. M. Zerankeshi, et al., Ceram. Int. 48, 2264722663 (2022) [2] Charles H. Turner. Ann. N.Y. Acad. Sci. 1068: 429446 (2006)[3] C. Schopper, et al., J. Biomed. Mater. Res. Part B: Appl. Biomater. 74B, 458467 (2005)
Improved reproducibility of glucose oxidation of copper hydroxide nanosheet-modified electrode with polyurethane coatings,
International Conference on Advanced Materials Development and Performance 2024 (AMDP 2024), PB30, Tokushima, Sep. 2024.- (要約)
- Quantitative analysis of glucose is used in various fields. Compared to precious metals (Pt, Au, etc.), the transition metal Cu is inexpensive, and sensors using copper-based compounds are known to exhibit excellent catalytic properties and stability, making them promising candidates for non-enzymatic electrodes.[1] In our laboratory, we have synthesized copper hydroxide nanosheets, which catalyze the electrolytic oxidation of glucose.[2] However, this electrode was unstable during repeated measurements. In this study, the reproducibility of the electrode was improved by coating it with polyurethane. The working electrode was prepared as follows. The copper hydroxide nanosheets dispersion in 1-butanol were prepared according to the previous report.[2] Ketjen black was mixed with the dispersion of copper hydroxide nanosheets and this mixture was cast onto the surface of a disk electrode and dried. Then DMF and THF solution of polyurethane was cast over it as a protective layer. Electrochemical measurements of this working electrode were carried out in a standard one-compartment cell equipped with a platinum wire counter electrode and an Ag/AgCl reference electrode in 0.1 M NaOH solution. Amperometry was measured at +0.55 V vs. Ag/AgCl with continuous addition of glucose solution. The electrodes without the polyurethane cover showed a current response only during the first measurement, with almost no response in subsequent measurements. Electrodes covered with polyurethane were capable of multiple measurements, although the amount of current varied because the amount of polyurethane covered was not constant. For the one electrode with the polyurethane cover, the sensitivity in the first measurement was 27.4 mA mM-1 cm-2, and from the second to the sixth measurements, the sensitivity gradually decreased from 63.1 mA mM-1 cm-2 to 50.5 mA mM-1 cm-2. For the other electrode with the polyurethane cover, the results showed that the values gradually decreased from 104.8 mA mM-1 cm-2 to 14.4 mA mM-1 cm-2 over the ten measurements. The electrodes were left in the electrolyte solution for one day and the eleventh measurement yielded a value of 7.4 mA mM-1 cm-2. These results show that using polyurethane as a protective layer significantly improves the stability of the electrodes during multiple measurements.[1] Z. Amirzadeh et al., Synth. Met., 245, 160-166, 2018.[2] M. Kurashina et al., ESC Trans., 86(15), 23-26, 2018.
Carbon Dioxide Reduction using Copper Hydroxide Nanosheet Modified Electrode,
International Conference on Advanced Materials Development and Performance 2024 (AMDP 2024), PB29, Tokushima, Sep. 2024.- (要約)
- Electrochemical reduction of carbon dioxide using transition metal catalysts can produce carbon monoxide and formic acid, both of which are used in large quantities around the world. Copper is the only catalyst that can produce industrially useful ethylene, in addition to these products, but it also produces other products. Since product selectivity is affected by the structure of the catalyst, the development of novel nanostructured copper catalysts is expected. In our laboratory, we have synthesized copper hydroxide nanosheets by introducing long-chain alkyls to the interlayer of basic copper acetate to expand the basal spacing and disperse them in 1-butanol. When applied to electrode modification, the nanosheets were found to be capable of electrolytic oxidation of glucose.[1] In this study, we investigate the reduction of carbon dioxide at electrodes using copper hydroxide nanosheets. Layered basic copper acetate Cu2(OH)3(CH3COO)·H2O was synthesized as previously reported.[2] This compound was reacted with sodium oleate aqueous solution at 30 °C for one day, collected by centrifugation. X-ray diffraction showed that the basal spacing of Cu2(OH)3(CH3COO)·H2O was 0.93 nm but expanded to 3.29 nm after the reaction, indicating that the interlayer acetate ions were exchanged for oleate ions. The ion exchanger was dispersed in 1-butanol at a ratio of 1.0 mg/mL to obtain the nanosheet dispersion. The dispersion was dropped onto a glassy carbon (GC) electrode and dried to prepare a working electrode. Cyclic voltammetry (CV) was measured using this as the working electrode in 0.5 M sodium hydroxide aqueous solution as the electrolyte with an Ag/AgCl electrode as the reference electrode and a platinum wire as the counter electrode, and the potential was swept from the open circuit potential to -1.2 V vs. Ag/AgCl. The CV was measured before and after carbon dioxide bubbling. No significant peak was observed before bubbling, but after carbon dioxide bubbling, a reduction current peak was observed at 1.0 V, which is considered to be the reduction peak of carbon dioxide. When carbon dioxide was blown in again, it did not react. We are in the process of studying the continuing electrolytic reduction of carbon dioxide.[1] M. Kurashina et al., ESC Trans., 86(15), 23-26, 2018.[2] K. Sotowa et al., Applied Mechanics and Materials, 625, 201-204, 2014.
An Innovative Approach to Enhancing Biocompatibility of Metal Surfaces,
12th World Biomaterials Congress (WBC 2024), OS4-10-3, Daegu, May 2024.- (要約)
- Medical devices such as stents and ventricular assist devices, which are in direct contact with blood, must have excellent biocompatibility on the device surface, since fibrinogen and platelets can be adsorbed and thrombi can be formed. For this purpose, it is considered useful to coat the surface with a material having zwitterionic ions that express high hydrophilicity. However, since methacrylate polymers with zwitterionic ions are water-soluble, stable surface modification is achieved by forming and fixing chemical bonds to the surface, or by synthesizing water-insoluble copolymers with hydrophobic methacrylate and coating them. On the other hand, we have recently developed a new compound, 2-((2-(methacryloyloxy)ethyl)dimethylammonio)ethyl hydrogen phosphate (MCHP), in which the order of the positively charged quaternary amine portion and the negatively charged phosphoric acid portion of the polar group of 2-methacryloyloxyethylphosphorylcholine (MPC) is reversed, and was confirmed that biocompatibility can be introduced by using the obtained polymer. MCHP has a phosphoric acid group at its terminus, which may form bonds to stainless steel and Nitinol surfaces, and thus can be stably modified. In this study, we attempted to form biocompatible surfaces by immersing samples of stainless steel and Nitinol in an aqueous solution of a single polymer of MCHP polymer and then rinsing them with water. As a result, excellent biocompatibility was formed on both samples, and the biocompatibility was maintained even after prolonged immersion in saline solution. In the same way, when the Nitinol stent was treated with MCHP polymer coating and blood circulation experiments were conducted, the untreated sample showed significant platelet adhesion, whereas the MCHPpolymer treated sample showed very little platelet and thrombus adhesion, confirming anti-thrombogenic properties equivalent to the commercially available treatment method.
Preparation of bio-printing scaffold using 2-(methacryloyloxy)ethyl cholinephosphate,
12th World Biomaterials Congress (WBC 2024), P2-086, Daegu, May 2024.- (要約)
- Reconstruction procedures for patients afflicted with bone abnormalities resulting from maxillofacial trauma and periodontal disease frequently necessitate the utilization of bone powder and bone regeneration materials. The surgical procedure is complicated and takes a significant amount of time. Bio-printing, a significant technique within the field of tissue engineering, possesses the capability to fabricate personalized regeneration graft utilizing preoperative images. Moreover, it has the potential to alleviate challenges encountered by surgeons during surgical procedures. Recently, we have succeeded tosynthesize 2-(methacryloyloxy)ethylcholine phosphate (MCP), in which 2-methacryloyloxyethyl phosphorylcholine (MPC)polar groups order is reversed. Since MCP has phosphoric acid as a terminal group, MCP and its polymers have a negative charge even in the acidic region and show excellent biocompatibility in wide pH range. In addition, MCP has unique adsorption characteristics not found in MPC. The bioink formulation involved the combination of MCP and calcium triphosphate, followed by the incorporation of a photoinitiator to yield a compound capable of undergoing curing through exposure to ultraviolet (UV) radiation. The bio-printer was utilized proficiently in the fabrication of the scaffold's structure, which subsequently underwent a curing process that rendered it insoluble property. It is expected that this technique will possess potential uses in the field of bone regeneration and in the therapeutic intervention for individuals with craniofacial injuries.
Preparation of biocompatible surface using a new phospholipid analogue polymer,
12th World Biomaterials Congress (WBC 2024), P1-037, Daegu, May 2024.- (要約)
- Zwitterionic polymer coatings on biomedical devices are considered an effective and promising way to improve the biocompatibility of materials and reduce the secondary damage that implanted materials can cause to the human body. Polymers prepared from the zwitterionic monomer 2-methacryloyloxyethyl phosphorylcholine (MPC) have been widely commercialized for this purpose. However, our recent studies have shown that MPC polymers become positively charged at low pH, and their biocompatibility decreases with decreasing hydrophilicity. It is well known that under conditions such as inflammation, the local environment within the human body decreases to acidic levels. Therefore, it is desirable for devices implanted in the body to show high biocompatibility even in acidic regions. On the other hand, we have recently succeeded to synthesize 2-(methacryloyloxy) acetylcholine phosphate (MCP), in which the order of MPC and the positively charged quaternary amine moiety and the negatively charged phosphoric acid moiety are reversed. Since MCP has phosphoric acid as a terminal group, MCP and its polymers are expected to have a negative charge in the acidic region and exhibit excellent biocompatibility. In this study, MCP polymer modification such as MCP polymer brush formation using SI-ATRP was employed, and protein adsorption tests were performed in different pH region. MPC polymer modified samples were prepared in a similar manner and compared. As a result, no significant difference was observed between MCP and MPC in the protein adsorption test in the neutral region, but a clear difference was observed in the acidic region, confirming that the modified surface obtained with MCP is superior. The modified surface obtained with MCP showed no decrease in hydrophilicity in the acidic region.
Electrochemical Reduction of CO2 using Au@Pt Nanoparticle and Copper Hydroxide Nanosheet Electrode, GoldPlatinum Bimetallic Nanoparticles-decorated Copper hydroxide nanosheets Boosts Carbon Dioxide Reduction to Industrial Chemicals: An Electrochemical Way of Conversion,
The 10th International Forum on Advanced Technologies (IFAT 2024), 12-16, Tokushima, Mar. 2024. NAKANO Kiichi, YUMENG ZHAO, Masashi Kurashina, Hitoshi Matsuki and Mikito Yasuzawa :
Evaluation of nonspecific adsorption-suppressed surface prepared using Photo-ATRP,
4th International Conference on Nanomaterials and Advanced Composites (NAC 2023) Abstract Booklet & Event Agenda, 122, Busan, Nov. 2023. Zhao Yumeng, Masashi Kurashina, Hitoshi Matsuki and Mikito Yasuzawa :
Preparation and Biocompatibility Evaluation of the Surface Modified with 2-Methacryloyloxyethyl Choline Phosphate,
4th International Conference on Nanomaterials and Advanced Composites (NAC 2023) Abstract Booklet & Event Agenda, 112, Busan, Nov. 2023. Masashi Kurashina, Qiu Zheng-Wei, Mikito Yasuzawa and Bai Meng-Yi :
Electrochemical Reduction of CO2 using Au@Pt Nanoparticle and Layered Copper Hydroxide Electrode,
4th International Conference on Nanomaterials and Advanced Composites (NAC 2023) Abstract Booklet & Event Agenda, 37, Busan, Nov. 2023. Zhao Yumeng, Masashi Kurashina, Hitoshi Matsuki and Mikito Yasuzawa :
Preparation and Biocompatibility Evaluation of the Surface Modified with Zwitterionic Polymer,
the 3rd International Conference on Nanomaterials and Advanced Composites, Tokushima, Jul. 2022. Haruka Tsubohira, Hiroki Ishikawa, Fumiaki Suzuka, Masashi Kurashina and Mikito Yasuzawa :
Improvement of Reproducibility of Glucose Oxidation Electrode Using Copper Hydroxide Nanosheets,
the 3rd International Conference on Nanomaterials and Advanced Composites, Tokushima, Jul. 2022. Masashi Kurashina, Daiki Kato, LI HAOYUAN, Keita Shiba, Yuta Morishita, Kazuki Shibata, Quyen Hong Ho and Mikito Yasuzawa :
Synthesis of N-methyl-D-glucamine Modified Chitosan Nanofibers for Boron Adsorption,
the 3rd International Conference on Nanomaterials and Advanced Composites, Tokushima, Jul. 2022. QUYEN HONG HO, Masashi Kurashina and Mikito Yasuzawa :
Removal of Phosphate from Aqueous Solution by Using Thermally Modified Clamshell,
International Conference on Advanced Materials Development and Performance 2021, Dalian, Oct. 2021. Masashi Kurashina, LI HAOYUAN, Quyen Hong Ho and Mikito Yasuzawa :
Synthesis of glycosylated chitosan nanofibers for boron adsorption,
International Conference on Advanced Materials Development and Performance 2021, Dalian, Oct. 2021. Zhao Yumeng, Tsubasa Miki, Toshiki Nakao, Masashi Kurashina, Yukihiro Arakawa, Yasushi Imada, Keiji Minagawa, Hitoshi Matsuki and Mikito Yasuzawa :
Preparation of Biocompatible Surface Using Zwitterionic Polymer,
6th International Forum on Advanced Technologies, Tokushima, Mar. 2020. Mikito Yasuzawa :
Preparation of glucose sensor using electrodeposition method and its application to in vivo measurement,
The International Joint Meeting of the Polarographic Society of Japan and National Taiwan University, Taipei, Nov. 2019. Mikito Yasuzawa :
Fabrication of implantable biosensor for in vivo glucose monitoring,
The 2nd International Conference on Nanomaterials and Advanced Composites, Taipei, Aug. 2019. Mikito Yasuzawa, Jhong Huan-Ping, Masashi Kurashina, Chen-Hao Wang and Wei-Hung Chiang :
Glucose Sensor Prepared By the Immobilization of Glucose Oxidase Together with Nanocarbons and Prussian Blue By Electrodeposition Procedure,
235th ECS Meeting, Dallas, May 2019. Mikito Yasuzawa, Jhong Huan-Ping, Masashi Kurashina, Chen-Hao Wang and Wei-Hung Chiang :
Fabrication of Glucose Sensors Prepared by the Electrodeposition of Glucose Oxidase and Nanomaterials,
5th International Forum on Advanced Technologies, Taipei, Mar. 2019. Ono Ryosuke, Masashi Kurashina, Mikito Yasuzawa, Yasuhide Ohno and Masao Nagase :
Fabrication of Nanopillars Using Focus Ion Beam-Chemical Vapor Deposition Method,
5th International Forum on Advanced Technologies, Taipei, Mar. 2019. Taniguchi Yoshiaki, Miki Tsubasa, Yasuhide Ohno, Masao Nagase, Yukihiro Arakawa and Mikito Yasuzawa :
Observation of the interaction between avidin and iminobiotin using graphene FET on SiC substrate,
31th International Microprocesses and Nanotechnology Conference (MNC2018), No.16P-11-3, Sapporo, Japan, Nov. 2018. Masashi Kurashina, Suzuka Fumiaki and Mikito Yasuzawa :
Electrochemical Oxidation of Glucose Using Copper Hydroxide Nanosheets,
Americas International Meeting on Electrochemistry and Solid State Science (AiMES 2018), Cancun, Oct. 2018. Mikito Yasuzawa, Nakataki Shinsaku, Li Jiang, Masashi Kurashina and Harada Toshihiko :
Sensitivity Improvement of a Low-Invasive Type Amperometric Glucose Sensor,
Americas International Meeting on Electrochemistry and Solid State Science (AiMES 2018), Cancun, Oct. 2018. Jhong Huan-Ping, Wang Chen-Hao, Chang Sun-Tang, Huang Hsin-Chih and Mikito Yasuzawa :
The SeCN- Ions- Decorated Cobalt Selenide Catalyst for Oxygen Reduction Reaction and Application in Alkaline Fuel Cell,
2018 International Conference on Solid State Devices and Materials (SSDM2018), Tokyo, Sep. 2018. Mikito Yasuzawa, Masahiro Uchimaru, Jhong Huan-Ping, Masashi Kurashina, Chen-Hao Wang, Yusuke Fuchiwaki and Toshihiko Harada :
Electrodeposition of Both Carbon Nanotube and Glucose Oxidase on Pt Electrode Using a Dispersed Electrolytic Solution,
233rd ECS Meeting, Seattle, May 2018. Jhong Huan-Ping, Masahiro Uchimaru, Shunsuke Isoai, Masashi Kurashina, Mikito Yasuzawa, Chen-Hao Wang, Wei-Hung Chiang, Yusuke Fuchiwaki and Toshihiko Harada :
Immobilization of Nanocarbons and Glucose Oxidase by Electrodeposition Method for Glucose Sensor Fabrication,
22nd Topical Meeting of the International Society of Electrochemistry, Tokyo, Apr. 2018. Quyen Hong Ho, Maki Yoshioka, Thuy Thi Xuan Le, Masashi Kurashina and Mikito Yasuzawa :
Effective Phosphate Removal from Aqueous Solution Using Environmental-Friendly Adsorbent'',
4th International Forum on Advanced Technologies, Tokushima, Mar. 2018. Jhong Huan-Ping, Mikito Yasuzawa, Masashi Kurashina, Masahiro Uchimaru, Chen-Hao Wang and Wei-Hung Chiang :
Immobilization of Enzyme by Modifying with Detergent and Polymer in Glucose Biosensor Detection,
4th International Forum on Advanced Technologies, Tokushima, Mar. 2018. Yoshiaki Taniguchi, Tsubasa Milki, Yasuhide Ohno, Masao Nagase, Yukihiro Arakawa, Yasushi Imada, Keiji Minagawa and Mikito Yasuzawa :
Intrinsic response of protein adsorption to graphene film on SiC substrate,
Proceedings of 2017 International Conference on Solid State Devices and Materials, Sep. 2017. Thuy Thi Xuan Le, Suong Thi Le, Mai Thi Sao Nguyen, Cuong Phuoc Le, Thoa Thi Kim Pham, Quyen Hong Ho and Mikito Yasuzawa :
Purification of Groundwater Contaminated Iron and Manganese by Effective Cost Filter Materials for Households in Rural Areas,
International Conference on Advanced Materials Development and Performance 2017, Pune, Jul. 2017. Tsuyoshi Tsuda, Mikito Yasuzawa, Yasuhide Ohno and Masao Nagase :
Electrical characteristic evaluation of Graphene on SiC,
International Conference on Advanced Materials Development and Performance 2017, Pune, Jul. 2017. Mikito Yasuzawa, Shinsaku Nakataki, Toshihiko Harada, Jiang Li, Yusuke Fuchiwaki and Masashi Kurashina :
Low invasive biosensor for continuous glucose monitoring,
International Conference on Advanced Materials Development and Performance 2017, Pune, Jul. 2017. Masashi Kurashina, Daiki Ikeuchi, Masaki Ohara, Toshio Takayanagi and Mikito Yasuzawa :
Syntheses and Properties of Copper Hydroxide Nanosheets and Controlled Deposition,
International Conference on Advanced Materials Development and Performance 2017, Pune, Jul. 2017. Quyen Hong Ho, Maki Yoshioka, Thuy Thi Xuan Le, Masashi Kurashina and Mikito Yasuzawa :
Eco-Friendly Removal of Phosphate from Aqueous Solution Using Natural Dietary Fibers and Minerals,
International Conference on Advanced Materials Development and Performance 2017, Pune, Jul. 2017. Mikito Yasuzawa, Jiang Li, Shinsaku Nakataki, Yusuke Fuchiwaki and Toshihiko Harada :
Preparation of Glucose Sensor for Low Invasive In Vivo Measurement,
231th ECS Meeting, New Orleans, May 2017. Mikito Yasuzawa, Daisuke Mima, Shunsuke Isoai, Masashi Kurashina, Yusuke Fuchiwaki and Toshihiko Harada :
Preparation of Enzyme-Immobilized Film Using Cellulose Nanofibers,
3rd International Forum on Advanced Technologies, 花蓮, Mar. 2017. Taniguchi Yoshiaki, Miki Tsubasa, Mitsuno Takanori, Yasuhide Ohno, Masao Nagase, Keiji Minagawa and Mikito Yasuzawa :
Protein adsorption characteristics on bare and phosphorylcholine-modified graphene films on SiC substrate,
29th International Microprocesses and Nanotechnology Conference (MNC2016), No.11P-11-16, Kyoto, Japan, Nov. 2016. Mikito Yasuzawa, Daisuke Mima, Yusuke Fuchiwaki and Toshihiko Harada :
Enzyme-immobilized electrode prepared using cellulose nanofiber,
PRiME 2016, Honolulu, Hawaii, USA, Oct. 2016. Mikito Yasuzawa :
Development of Biosensors for Continuous Glucose Monitoring,
2016 Young Chemical Engineer Symposium, Taipei, Sep. 2016. Mikito Yasuzawa, Jiang Li, Yusuke Fuchiwaki, Toshihiko Harada and Noriko Minamimoto :
Preparation and evaluation of low-invasive type amperometric glucose sensor,
The 16th International Meeting on Chemical Sensors, Jeju, Korea, Jul. 2016. Yoshiaki Taniguchi, Tsubasa Miki, Takanori Mitsuno, Yasuhide Ohno, Masao Nagase, Keiji Minagawa and Mikito Yasuzawa :
Hydrophilic Graphene Film by Molecular Functionalization,
The 43rd International Symposium on Compound Semiconductor, Jun. 2016. Mikito Yasuzawa, Jiang Li and Yusuke Fuchiwaki :
Fabrication and In Vivo Evaluation of Low-Invasive Patch Type Glucose Sensors,
229th ECS Meeting, San Diego, May 2016. Yoshinori Otsuka, Yusuke Tanatsugu, Shinsuke Nakanishi, Mikito Yasuzawa and Yusuke Fuchiwaki :
Functional surface modification using perhydropolysilazane,
2nd International Forum on Advanced Technologies, Tokushima, Mar. 2016. Shin Ueoka, Mikito Yasuzawa, Tomoki Yabutani and Kanemi Abe :
Removal of cesium ions using magnetic flocculant,
2nd International Forum on Advanced Technologies, Tokushima, Mar. 2016. Yusuke Tanatsugu, Mikito Yasuzawa, Chia-Chi Yu and Jinn Chu :
Evaluation of thin film metallic glass as a biomaterial,
2nd International Forum on Advanced Technologies, Tokushima, Mar. 2016. Mikito Yasuzawa, Jiang Li and Kazuaki Edagawa :
Fabrication of amperometric enzyme sensor for in vivo glucose monitoring,
2nd International Forum on Advanced Technologies, Tokushima, Mar. 2016. Mikito Yasuzawa :
Cellulose nanofiber for enzyme-immobilization,
International Conference on Functional Materials and Microwaves (ICFMM-2015), Aurangabad, Dec. 2015. Mikito Yasuzawa, Yuya Omura, Kentaro Hiura, Jiang Li, Yusuke Fuchiwaki and Masato Tanaka :
Preparation of glucose oxidase-immobilized electrodes using cellulose aqueous solution,
228th ECS Meeting, Phoenix, Oct. 2015. Jiang Li, Kentaro Hiura, Mikito Yasuzawa and Yusuke Fuchiwaki :
Fabrication of low-invasive patch glucose sensors,
228th ECS Meeting, Phoenix, Oct. 2015. Mikito Yasuzawa, Jiang Li, Masahiro Uchimaru, Yusuke Isoai and Yusuke Fuchiwaki :
Fabrication of low-invasive type biosensor for continuous glucose monitoring,
The 66th Annual Meeting of the International Society of Electrochemistry, Taipei, Oct. 2015. Yusuke Tanatsugu, Chia-Chi Yu, Jinn Chu and Mikito Yasuzawa :
Metallic glass coating for non-sticky medical needles,
13th International Symposium on Sputtering & Plasma Processes (ISSP 2015), Kyoto, Jul. 2015. Mikito Yasuzawa and Kazuaki Edagawa :
In Vivo glucose measurement using fine needle type amperometric glucose sensor,
227th ECS Meeting, Chicago, May 2015. Mikito Yasuzawa :
Fabrication of glucose oxidase immobilized electrode for in vivo glucose monitoring,
Pre-symposium Indo-Japanese Workshop on Sensing Mechanisms, Materials & Applications, Pune, Mar. 2015. Mikito Yasuzawa :
Patch type glucose sensor for low-invasive glucose monitoring,
India Japan Workshop on ``Nanotechnology: Synthesis & Sensing Applications'', Pune, Oct. 2014. Mikito Yasuzawa and Shinya Furukawa :
Immobilization of enzyme using electrodeposition technique for biosensor application,
NANOCON014, Pune, Oct. 2014.- (要約)
- Enzyme immbilization technique using the combination of electrodeposition/electropolymerization procedures differ with common electropolymerization procedure,since enzyme could be immobilized in high density and the amount of electrogenerated polymer in enzyme film is low. Therefore, this procedure is useful for the fabrication of biosensor with high sensitivity and fast response rate. In this presentaion,details on the preparation and properties of the obtained enzyme-immobilized film will be introduced.
Attractive Materials for Engineering Chemistry Education Performed under High School/University/Graduate School Partnership,
Proceedings of Asian Conference on Engineering Education 2014 (ACEE2014), Kumamoto, Oct. 2014. Kentaro Hiura, Shinya Furukawa, Yusuke Fuchiwaki and Mikito Yasuzawa :
Preparation of Glucose Oxidase Immobilized Electrode Using Electrodeposition Procedure and Its Glucose Sensor Properties,
2014 ECS and SMEQ Joint International Meeting, Cancun (Mexico), Oct. 2014.- (要約)
- The importance of glucose determinations for the diagnosis and effective treatment of diabetes has been well recognized. Therefore, much effort has been devoted to developing an effective sensor for the continuous estimation of glucose concentration in subcutaneous tissue [1]. Miniaturization of the sensor device is an important subject, since smaller devices are less invasive, both physically and psychologically. A finer device will excite fewer pain receptors in the skin and will cause less tissue damage and less pain. However, fabrication of finer sensor request precise technique to immobilize enzyme in a specific area. Conventional methods of enzyme immobilization are covalent attachment,cross-linking, hydrogel entrapment, electropolymerized polymer entrapment, and the combination of two or more methods. Among the variety of procedure for the immobilization of enzyme, electropolymerized polymer entrapment is interesting, since the enzyme will be immobilized just at the position where the electricity was passed. Similar to this procedure, Matsumoto et al reported that the layer of enzyme can be formed on the electrode by applying a potential of 1.3 V (vs Ag/AgCl) in the enzyme solution containing a nonionic surfactant such as Triton X-100. Since the obtained enzyme layer was not stable, they formed a electropolymerized polyphenol film in order to improve the stability, which also functioned as a permselective film to eliminate the influence of electroactive species excite in the biological fluid such as ascorbic and uric acids. In this study, glucose oxidase was immobilized using electrodeposition procedure and polymer film was formed to stabilize the enzyme film. Glucose sensor properties of the obtained electrode were investigated using in vitro and in vivo measurements.
Development of Minimally Invasive Biosensor for Continuous Glucose Monitoring,
2014 ECS and SMEQ Joint International Meeting, Cancun (Mexico), Oct. 2014.- (要約)
- Good control of blood glucose degree is quite important for the prevention of serious diabetes complications onset and progression. Accurate recognition of the blood glucose degree helps the patient to provide appropriate treatments, such as insulin therapy. Recently, implantable glucose sensors for continuous glucose monitoring (CGM) are of significant importance on diabetic health care, since it not only lower the physical and mental load on glucose measurement, but also present continuous glucose trend, which is useful for treatment evaluation. However, since the length of sensor device inserted in skin is about 1 cm, development of lower invasive CGM system is expected for the improvement of diabetic patients quality of life. In this study, a low invasive patch type glucose sensor, which has sensing region at the tip inside of a tube, was proposed. The schematic illustration of the tip of such glucose sensor is shown in Figure 1. Since the sensing region is at the inside of a fine needle tube, it requires only the sensor tip to be implanted in the tissue for glucose monitoring. In other words, it can be possible to perform as a patch type sensor, which impresses the user as a sticking sensor instead of implanting sensor. Glucose oxidase was immobilized inside the tube using the combination of electrodeposition and electropolymerization technique, which was similar to the procedure proposed by Wilson's group [1,2]. That is, phosphate buffer solution (pH 7.0) containing GOx and Triton X-100 was first poured inside the tube electrode and applied a potential of 1.3 V (vs Ag/AgCl) for 1 h to form GOx layer on the surface. Phosphate buffer solution containing o-phenylenediamine (o-PD) was next poured inside the tube and a potential of 0.7 V (vs Ag/AgCl) was applied for 15 min to induce the electropolymerization of o-PD. Properties of the obtained sensor were evaluated both by in vitro and in vivo measurements.
Removal of cesium ions using prussian blue and magnetic flocculant,
International Conference on Advanced Materials Development and Performance 2014, Busan, Jul. 2014.- (要約)
- After Fukushima Daiichi nuclear disaster of March 2011, large amounts of radionuclides such as cesium ion have been scattered in and around Fukushima prefecture, Japan. Since radioactive 137Cs has a long half-live of thirty years, citizen in the area feel apprehensive about its influence to the health. Therefore, it is essential to accelerate the removal and the management of radioactive polluted materials from the area. Recently, considerable efforts have been directed toward development of various separation methods for radioactive Cs isotopes, such as coagulation, ion exchange, adsorption, and membrane processes. Among them, adsorption has been most widely used and filtration is the general procedure for the separation of treated water and radioactive wastes. However, filtration method requires periodic replacement of hazardous radioactive filter. In this study, prussian blue (PB) nanoparticle was employed for selective adsorption of cesium ion and Cs-absorbed PB was collected with magnetic flocculants using magnetic field. Conditions for removal operation of cesium from tap water were investigated. We succeeded to remove more than 90% of cesium ion from tap water containing 5 ppm Cs.
Preparation of hydrophobic thin films using perhydropolysilazane,
International Conference on Advanced Materials Development and Performance 2014, Busan, Jul. 2014.- (要約)
- Perhydropolysilazane (PZ) is known to convert into high-density silica by simply heating in the presence of adequate oxygen and water. We have recently verified that PZ can be employed as a material to prepare functional surface by simply attaching the functional compound with hydroxyl group, on the time PZ was heated to produce silica film. In this study, several compounds with hydroxyl group, such as silanol-terminated polydimethylsiloxane, were attempted to immobilize on the surface of substrate using PZ.
Preparation and evaluation of a fine tapered needle type glucose sensor,
International Conference on Advanced Materials Development and Performance 2014, Busan, Jul. 2014.- (要約)
- A fine needle type glucose sensor, which has a sensing region at the inside wall of fine tapered tube, was prepared and applied for low invasive glucose monitoring. Fine tapered tube of Pt-Ir alloy was prepared by electrolytic polishing Pt-Ir tube in 2.0 M NaCl aqueous solution. The enzyme glucose oxidase was immobilized on the platinum surface located in the tube by the combination of electrodeposition and electropolymerization of o-phenylenediamine. Amperometric responses of the prepared electrodes to glucose were measured at a potential of 0.60 V (vs Ag/AgCl). The tube type electrode showed good response to glucose and functioned as glucose sensor.
Stabilization of enzyme-immobilized film prepared using electrodeposition procedure,
International Conference on Advanced Materials Development and Performance 2014, Busan, Jul. 2014.- (要約)
- Enzyme immobilization method play a big role on the property of enzyme sensor, since enzyme is the center of glucose recognition and its amount and activity effect the sensor sensitivity. Conventional methods of enzyme immobilization are covalent attachment, cross-linking, hydrogel entrapment, electropolymerized polymer entrapment, and the combination of two or more methods. Among the variety of procedure for the immobilization of enzyme, electropolymerized polymer entrapment is interesting, since the enzyme will be immobilized just at the position where the electricity was passed. Similar to this procedure, Matsumoto et al reported that the layer of enzyme can be formed on the electrode by applying a potential of 1.3 V (vs Ag/AgCl) in the enzyme solution containing a nonionic surfactant such as Triton X-100. Since the obtained enzyme layer was not stable, they formed a electropolymerized polyphenol film in order to improve the stability. In this study, polymer film generated by photopolymerization was attempted by introducing methacrylate derivatives in the electrodeposition electrolyte followed by UV irradiation polymerization. Variety of methacrylate derivatives were employed and the property of the obtained film were investigated.
Preparation of micro-biosensor for continuous glucose monitoring,
International Conference on Advanced Materials Development and Performance 2014, Busan, Jul. 2014.- (要約)
- Real-time monitoring of valuable compound biological compounds such as glutamate, lactate, pyruvate, acetylcholine, and glucose in single cells, tissue slices, and sensitive neurological applications has become a key research endeavor. However, accurate and specific measurement in these environments with minimal perturbation of the biological system is optimally obtained with micro-sensors less than 10µm in diameter. In this study, glucose sensors with a diameter of less than 10 µm were fabricated. Glucose oxidase (GOx) was first electrodeposited on the electrode by applying potential in pH 7 buffer solution containing both Triton-X and GOx.The electropolymerization of o-phenylene diamine was then perform to stabilize the enzyme film. Amperometric responses of the prepared electrodes to glucose were examined by measuring the electrooxidation current for hydrogen peroxide detection. Glucose sensor properties, such as sensor sensitivity and the interferences of electroactive compounds (interferants) existing in biological fluids, were investigated and procedure to improve the sensor properties will be presented in the conference.
In vivo evaluation of fine needle type glucose sensors implanted in rabbit blood vessel,
224th ECS Meeting, San Francisco, Oct. 2013. Mikito Yasuzawa, Shinya Sato and Kazuaki Edagawa :
Patch type glucose sensor for low-invasive glucose monitoring,
224th ECS Meeting, San Francisco, Oct. 2013. Kentaro Hiura, Shinya Furukawa, Kazuaki Edagawa and Mikito Yasuzawa :
Preparation of Enzyme-Immobilized Biosensor by the Combination of Electrodeposition and Electropolymerization,
223rd ECS Meeting, Toronto, May 2013. Kazuaki Edagawa, Hiroki Takaoka, Tomoki Yabutani and Mikito Yasuzawa :
Preparation of Fine Implantable Needle-Type Glucose Lactate Dual Biosensors Using γ-Polyglutamic Acid,
223rd ECS Meeting, Toronto, May 2013. Yusuke Tanatsugu, Shinsuke Nakanishi, Kiyoto Ikebata, Kotaro Rikitake and Mikito Yasuzawa :
Preparation and evaluation of biocompatible surface using perhydropolysilazane,
245th ACS National Meeting and Exposition, New Orleans, Apr. 2013. Kazuaki Edagawa and Mikito Yasuzawa :
Preparation of Fine Implantable Needle Type Biosensors for Blood Vessel Glucose Monitoring,
PRiME 2012, Honolulu, Hawaii, USA, Oct. 2012.- (要約)
- Fine needle type glucose sensors with variety of outer membrane were prepared and their glucose sensor properties were evaluated by in vitro measurement in phosphate buffer solution and horse serum, and in vivo measurement using the veins of rats and rabbits. Extra-outer membrane materials of polyglutamic acid (PGA) and heparin, which provide hydrophilic surface were introduced in addition to polyurethane/polydimethylsiloxane composite outer membrane. Glucose sensors without extra-outer film and with PGA extra-outer film showed glucose response on the day of implantation, while clear response was not obtained on the second day of implantation due to the adsorption of thrombus on the sensor surface. On the other hand, the sensor with heparin outer membrane provided satisfactory glucose response also on the second day.
Preparation of Flexible Micro-Glucose Sensor,
PRiME 2012, Honolulu, Hawaii, USA, Oct. 2012.- (要約)
- Measuring of valuable compound biological compounds such as glutamate, lactate, pyruvate, acetylcholine, and glucose in real-time for single cells, tissue slices, and sensitive neurological applications has become a key research endeavor. However, accurate and specific measurement in these environments with minimal perturbation of the biological system is optimally obtained with micro-sensors less than 10µm in diameter. To achieve this objective, glucose sensors with a diameter of less than 10 µm were fabricated using a core material of super-flexible Ni-Ti alloy. The 350 µm diameter of Ni-Ti alloy wire was reduced by a continuous dipping operation in etching solution. An electroactive surface was created by sputter coating with Pt film and then forming a dielectric coating with electrodeposition procedure over the Pt film. The dielectric layer was etched at the 10 µm tip to form a sensing cavity. Glucose oxidase (GOx) was immobilized on the sensing cavity by firstly electrodeposition by applying a constant potential of 1.3 V (vs Ag/AgCl) in 0.05 M phosphate buffer (pH 7.0) with 0.8 mM Triton-X, followed by the electropolymerization of o-phenylene diamine. Amperometric responses of the prepared electrodes to glucose were examined by measuring the electrooxidation current at a potential of 0.6 V (for hydrogen peroxide detection). The calibration of the sensor was carried out by adding increasing amounts of glucose to the stirred phosphate buffer solution (pH 7.4). GOx immobilized electrode performed good response up to 22 mM glucose. The interferences of electroactive compounds (interferants) existing in biological fluids to the glucose response were examined in the presence of their physiological maximum levels with the glucose concentration at 5.6 mM. The obtained sensor was not affected by the existence of interferants, such as ascorbic acid and uric acid.
Preparation of Nonspecific Adsorption Eliminating Surface Using Perhydropolysilazane,
PRiME 2012, Honolulu, Hawaii, USA, Oct. 2012.- (要約)
- Immunosensors based on binding reactions between antibody and antigen, have been reported for the quantitative determination of a broad range of analytes of clinical, medical, biotechnological, and environmental significance [1 4]. However, nonspecific adsorption can lead to a decline in sensor accuracy and sensitivity, and this has limited the further development of immunosensors toward practical application. Nonspecific adsorption decreases the signal-to-noise (S/N) ratio, preventing the improvement of immunosensor systems. Therefore, eliminating nonspecific adsorption is crucial in realizing a practical immunosensor system. On the other hand, perhydropolysilazane (PZ) is known to convert high-density silica by simply heating in the presence of adequate oxygen and water. We have recently confirmed that compounds having hydroxide group, such as such as polyethylene glycol (PEG), can be immobilized on the surface of silica by covering the PZ coated surface with compounds having hydroxide group before heating. Moreover, since compounds having hydroxide group were attached to the surface with covalent bonding, the thickness of the attached material was not affected by the amount of material and only monolayer was prepared. In this study, variety of compounds having hydroxide groups were employed and there property to eliminate the adsorption of proteins (biocompatibility) were investigated. Molar ratio of protein adsorption of fibrinogen to albumin (F/A molar ratio), which was adopted as the indicator of biocompatibility, was measured. Thin films were prepared on the surface of glass and metal plates. Hydrophilic surface modification was obtained using PEG. The water contact angle was lower on the surface prepared using higher molecular weight PEG. Although, the introduction of monoalkoxy PEG to the surface of silica was successfully performed, while dialkoxy PEG could not be immobilized on the surface. The F/A molar ratios were lowered by the surface modification of PEG. PEG surface modification contributed to improve the biocompatibility.
Fabrication of Minimally-Invasive Patch Type Glucose Sensors,
PRiME 2012, Honolulu, Hawaii, USA, Oct. 2012.- (要約)
- A fine tube type glucose sensor, which has a sensing region at the inside wall of fine tube tip, was prepared and applied for a minimally invasive glucose monitoring. The enzyme glucose oxidase was immobilized on the platinum surface located in the tube by the combination of electrodeposition and electro-polymerization of o-phenylenediamine. Amperometric responses of the prepared electrodes to glucose were measured at a potential of 0.60 V (vs Ag/AgCl). The tube type electrode showed good response with good linear relationship up to the glucose concentration of 22.4 M, which was actually higher than normal sensor without outer film for permeability restriction. This may due to its unique sensor structure.
Development of Minimally Invasive Glucose Sensor for Real-Time in vivo Monitoring,
The University of Tokushima New Technology Seminar, Palo Alto, Sep. 2011.- (要約)
- Continuous glucose monitoring (CGM) systems, which use a tiny sensor inserted under the skin to check glucose levels in tissue fluid, are becoming an important adjunct for the treatment of type 1 diabetes patients. However, sensors currently on the market are not small enough; minimization of both sensor diameter and insertion length are essential for the reduction of user physiological and mental load. We recently developed a unique glucose sensor featuring a localized sensing region in side the tip of a fine tapered tube. As a result, only the tip of this sensor must be inserted into the tissue. Our challenge now is to develop a patch-style sensor with an insertion length of less than 0.5 mm, so the sensor setting process can feel as painless ``sticking a patch'' rather than ``inserting a needle''.
Preparation and In Vivo Measurement of a Fine Needle Type Flexible Glucose Sensor,
62nd Annual Meeting of the International Society of Electrochemstry, Niigata, Sep. 2011.- (要約)
- 抗原抗体反応を用いた免疫センサは,超極微少濃度測定が期待できる一方,1サンプルごとに,高価な抗体を一定量使用するため,抗体の再生·再使用が可能なセンサの開発が望まれている.従来のアンペロメトリック免疫センサは,電極表面に抗原量に対応した抗原抗体サンドイッチ構造を形成させ,末端に結合した電気化学的活性物質の電気化学的検出を行うというものであり,抗体や抗原は分子量数万のタンパク質であるため,効率的な電気化学的検出には,電導性ワイヤリングを行う等,複雑なシステムが導入する必要があった.そのため抗体の再生·再使用には,抗体の活性低下の問題に加えて,電導性ワイヤリング等の特性変化等,解決すべき課題が多く,困難であった.そのため本研究では,抗体や抗原が反応するリアクターと電気化学検出を行うディテクターとを分離したシステムを導入し,リアクターの再生·再使用が可能なセンシングシステムの構築を試みた.その結果,0.5 % Tween 20 を含む 0.1 M 酢酸溶液を解離溶液に用いることにより,15 回のリアクターの再生が可能であることを見いだした.
Magnetic removal of cesium ions using zeolites and poly--glutamic acid coated Fe3O4 nanoparticles,
JAIMA Discussion on Analytical Science and Technology 2011, Chiba, Sep. 2011. Toshio Watanebe, Yohei Yamada, Tomoki Yabutani, Haruhiko Sakuraba and Mikito Yasuzawa :
Development of a thermostable Bilirubin oxidase electrodeposited electrode and its application of biofuel cell cathode,
JAIMA Discussion on Analytical Science and Technology 2011, Chiba, Sep. 2011. Le Thi Xuan Thuy, Mikito Yasuzawa and Tomoki Yabutani :
Removal of trace metals from aqueous solution by activated carbon adsorption and flotation using poly-glutamic acid,
Sixth International Conference on Advanced Materials Development and Performance, 81-82, Tokushima, Jul. 2011. Toshio Watanebe, Yohei Yamada, Junko Motonaka, Haruhiko Sakuraba, Mikito Yasuzawa and Tomoki Yabutani :
Preparation of an Electrode Modified with a Thermostable Enzyme Bacillus Subtilis CotA by Electrodeposition and its Application to Biofuel Cell Cathode,
Sixth International Conference on Advanced Materials Development and Performance, 74-75, Tokushima, Jul. 2011. Tomoki Yabutani, Hashimoto Tomohiro, Le Thi Xuan Thuy, Mikito Yasuzawa and Junko Motonaka :
Synthesis and characterization of amidoximated carbon for separating heavy metal,
International Congress of Analytical Sciences 2011, Kyoto, May 2011. Mikito Yasuzawa, Keiji Minagawa, Sachiyo Kamitani, Yuka Arai, Yuki Konishi, Shinsuke Nakanishi, Takuya Oshima, Junko Yamaguchi, Arisa Ishii, Tomoki Fujita, Hidemi Mishima, Akihiro Orino and Eisaku Satou :
Production of Chemistry Laboratory Class for Senior High School Freshmen,
Proceedings of Asian Conference on Engineering Education 2009 (ACEE2009), Busan, Oct. 2009. Sachiyo Kamitani, Yuka Arai, Yuki Konishi, Shinsuke Nakanishi, Takuya Oshima, Junko Yamaguchi, Arisa Ishii, Tomoki Fujita, Keiji Minagawa and Mikito Yasuzawa :
Chemistry Laboratory Class in Senior High School by University Students,
Proceedings of Asian Conference on Engineering Education 2009 (ACEE2009), Busan, Oct. 2009. Kazuaki Edagawa, Hiroki Takaoka, Takuya Matsunaga, Makoto Ichihashi and Mikito Yasuzawa :
Preparation of Needle Type Glucose Sensors Using γ-Polyglutamic Acid as an Enzyme-Immobilizing Substrate,
PRiME 2008, Honolulu, Hawaii, USA, Oct. 2008.- (要約)
- The importance of glucose determinations for the diagnosis and effective treatment of diabetes has been well recognized. Therefore, a large number of efforts have been devoted to make an effective sensor for a continuous estimation of glucose concentration in subcutaneous tissue. Typical implantable enzyme immobilized glucose sensors are composed of three layered films. 1) Inner layer film for permselective transportation in order to eliminate the influence of electroactive species exist in biological media ion (mainly ascorbic acid, uric acid and acetaminophen), 2) enzyme-immobilized layer and 3) outer layer for the elimination of protein adsorption that occur immediately when the sensors are inserted in the biological media. Negatively charged polymers like Nafion are commonly used as effectively inner layer permselective film. On the other hand, bovine serum albumin (BSA) is a popular material for the immobilization of enzyme. In this study, γ-polyglutamic acid (PGA) was applied as a permselective film and enzyme immobilizing substrate. was evaluated in phosphate buffer solution. The performance of the prepared sensors were evaluated in both phosphate buffer solution and horse serum sample.
Electrochemical Characterization of biosensors based on immobililzation of enzyme in amino acid N-substituted polypyrrole formed by electropolymerization,
AMDP 2008 (International Conference on Advanced Materials, Development and Performance 2008), 204, Beijing, Oct. 2008. Mikito Yasuzawa, Matsumoto Kazuki, Okada Hideya and Ichihashi Makoto :
Eco-Friendly Magnetic Flocculant for Water Purification,
AMDP 2008 (International Conference on Advanced Materials, Development and Performance 2008), Beijing, Oct. 2008. Mikito Yasuzawa and Hiroki Takaoka :
Preparation of a Super-Flexible Micro Glucose Sensor,
AMDP 2008 (International Conference on Advanced Materials, Development and Performance 2008), Beijing, Oct. 2008. Mikito Yasuzawa, Kazuaki Edagawa, Hiroki Takaoka and Makoto Ichihashi :
Preparation of glucose sensors by the electropolymerization of pyrrole derivatives in the presence of polyglutamic acid,
ACEC2008 (6th Asian Conference on Electrochemistry), Taipei, May 2008.- (要約)
- Glucose oxidase (GOx) immobilized electrodes prepared by the electro-polymerization of pyrrole derivates having phosphatidylcholine polar group, saccaride group, 3-(1-pyrrolyl)propyl-2-(trimethylammonium) ethylphosphate (PP3) and saccharide unit, 1-(6-D-gluconamidopropyl)-pyrrole (GP6) have good sensitivity and reproducibility. However, when considering the ultimate purpose of this sensor is to provide a continuous estimation of glucose, the lifetimes of the glucose sensors were not long enough. In this study, we attempted to improve the stability of the immobilized enzyme by introducing negatively charged dietary fiber, polyglutamic acid (PGA) in the enzyme-immobilized film, which can be stabilized due to the electrostatic interactions between positively charged polypyrrole and PGA. PGA was added in the solution of pyrrole and pyrrole derivatives (1-pyrrole-propionic acid (PPA), PC3 and GP6) and GOx, while the electorpolymerization process was performed. GOx immobilized electrode was than covered with a thin film of polyurethane. The obtained electrode showed higher sensor response stability than that without PGA, while still the response current was low on the electrode prepared with pyrrole and PPA. Moreover, obtained electrode produced good sensor response in both PBS solution and horse serum.
Water Purification Using Magnetic gamma-Polyglutamic Acid,
2007 MRS Fall Meeting, Boston, Nov. 2007. Mikito Yasuzawa and Hiroki Takaoka :
Preparation and Properties of Fine Super-Flexible Biosensors for In Vivo Measurements,
2007 MRS Fall Meeting, Boston, Nov. 2007. Mikito Yasuzawa, Kenji Moriyama and Hiroki Takaoka :
Selective Enzyme Immobilization Technique for Multi-Channel Enzyme Sensor Fabrication,
212th Meeting of the Electrochemical Society, Washington, D.C., Oct. 2007. Junko Motonaka, Tujimoto Masaki, Tomoki Yabutani, Sano Atsushi, Tani Yuji and Mikito Yasuzawa :
Characterization of Amperometric Glucose Sensor Prepared by Electropolymerization of Pyrroles,
From Small Molecules to Materials and Surfaces, Vol.1, 82-85, Rotorua, New Zealand, Dec. 2006.- (要約)
- Glucose is one of the most important analytes in the clinical field, particularly to determine accurate therapeutic treatment of diabetes.Glucose sensors modified with glucose oxidase have been extensively researched to improve their performance. In this work, the primary aim for using pyrroles was to correlate the methylene length with the performance of the glucose sensors. Furthermore, to ascertain function in a complex biological sample, the developed glucose sensors were used to determine glucose concentration in bovine serum. The Os-py's utilized were [Os(bpy)2(py(4)-bpy)]2+/3+, [Os(bpy)2(py(6)-bpy)]2+/3+, and [Os(DM-bpy)2(py(6)-bpy)]2+/3+.
- (キーワード)
- gludose sensor / electropolymerization / pyrroles
Fabrication of Multi-Channel Needle Type Biosensors Using Electrodeposition Procedure,
210th Meeting of The Electrochemical Society, Vol.2006-2, 2092, Cancun, Mexico, Nov. 2006. Mikito Yasuzawa, Shigeru Inoue, Hiroki Takaoka, Junya Murakami, Toshiyasu Shimizu and Shinji Imai :
In vivo measurement that Uses a New Miniature Flexible Glucose Sensor,
The 11th International Meeting on Chemical Sensors, 397, Brescia, Italy, Jul. 2006. Mikito Yasuzawa, Hiroki Takaoka, Shinya Furukawa, Toshiyasu Shimizu and Shinji Imai :
Fabrication of glucose micro sensor,
2004 Joint International Meeting, Vol.2004-2, 2192, Honolulu, Hawaii, USA, Oct. 2004.- (要約)
- 糖尿病患者にとって,日常生活における血糖コントロールは健康管理や治療に非常に重要であるため,痛みや違和感がなく,血糖値(グルコース濃度)を常時,容易にモニタリングできる体内埋込み型の微小·微細センサの開発が求められている.しかしながらこれまでに用いられている白金やカーボンファイバー等で微細化を行った場合,衝撃によって容易に変形や破損が起こるため,作製が困難であった.本研究では芯材に超弾性合金であるニッケル-チタン(Ni-Ti)線を用いることにより,適度な柔軟性が有し,衝撃に強く良好なセンサ応答を示す直径20ミクロン以下のセンサの作製に成功した.
Construction of automated biological fluid glucose measuring system,
2004 Joint International Meeting, Vol.2004-2, 2215, Honolulu, Hawaii, USA, Oct. 2004.- (要約)
- 生体液のグルコース濃度を容易再現性良く測定できるシステムの構築を行ったものである.糖尿病をはじめ,多くの生活習慣病は,ほとんど自覚症状が現れないため,その進行並びに改善の度合いを容易に知ることのできる検査法が求められている.尿は体内の状態を完全に反映することはないが,生体内の情報が多量に存在し,様々な生活習慣病のバロメーターになることに着目し,本研究では,特に軽度の糖尿病患者の健康管理に有効な尿中グルコース濃度の測定システムの構築を行った.グルコースの検出は酵素反応を電気化学的に測定する方法で行った.フロー測定システムの導入,並びに白金電極表面をポリマーで被覆することにより,再現性の高い測定結果が得られた.また尿の実サンプルを用いた測定でも良好な結果が得られている.
Preparation and Properties of Enzyme Micro Sensors,
10th International Meeting on Chemical Sensors, Tsukuba, Jul. 2004.- (要約)
- ニッケル-チタン(Ni-Ti)超弾性合金線の表面にスパッタリング装置を用いて白金薄膜を形成させ,その表面に電解重合法による酵素固定を行った微細針状酵素固定電極の作製を行った.酵素にグルコースオキシダーゼを用い,得られた電極のグルコースセンサ特性を調べたところ,グルコース濃度22 mmol dm-3まで良好なセンサ応答を示す直径50ミクロン以下のセンサの作製に成功した.
In vivo studies of Implantable Electrochemically Fabricated Glucose Sensors,
10th International Meeting on Chemical Sensors, Tsukuba, Jul. 2004.- (要約)
- センサ部位以外をテフロン膜で被覆した直径約0.2ミリの白金イリジウム合金を用い,センサ部位にポリジメチルシロキサン(PDS)とナフィオンの両ポリマ-の内部膜を形成し,さらに酵素(グルコースオキシダーゼ)の存在下,糖鎖を有するピロ-ル誘導体の電解重合を行うことにより,インビボ測定用針状グルコースセンサを作製した.ラットの皮下内組織にセンサを埋込,イソフルランのガス麻酔下,腹腔内にグルコースを注射注入し,センサ応答変化と,これと並行して尻尾の静脈から採血を行い,市販の血糖値計の値を比較したところ,良好な相関関係が見られ,生体内の糖濃度を測定するセンサとして機能することが分かった.
In vitro and In vivo Studies of Needle Type Glucose Sensors Using Electropolymerization Procedure,
204th Meeting of The Electrochemical Society, Vol.2003-2, 1457, Orlando, USA, Oct. 2003.- (要約)
- ポリジメチルシロキサンおよびナフィオンを内部膜に用い,ピロール基のN-置換基末端に糖鎖を有するピロ-ル誘導体1-(6-D-gluconamidohexyl) pyrrole (GHP) の電解重合により作製したグルコースセンサが,生体内温度にあたる40℃で測定を行った場合においても,約一ヶ月間安定した応答電流が得られ,またGHP の電解重合により形成した酵素固定膜が優れた生体適合性を有したことから,牛血清を用いたインビトロ測定並びにラットを用いたインビボ測定を行った.その結果,牛血清中の測定では,リン酸緩衝溶液中の測定に比べ,感度の低下が見られたが,良好なセンサ応答を示した.またラットを用いたインビボ測定においても,血糖値変化挙動に対応したセンサ応答が得られ,体内グルコース濃度測定に成功した.タンパク質等が多く存在する生体液中での測定では,タンパク質のセンサ表面への吸着を抑制するため,ポリウレタン等の外部膜を被覆する必要があるが,今回作製したセンサの酵素固定膜には,優れた生体適合性があるため,外部膜を被覆することなく,良好なセンサ応答を得ることができた.
Improvement of Immunosensor Accuracy by the Introduction of Nonspecific Adsorption Eliminating Reagents,
204th Meeting of The Electrochemical Society, Vol.2003-2, 59, Orlando, USA, Oct. 2003.- (要約)
- 抗原抗体反応を用いた免疫センサは,微少濃度測定が期待できる一方,抗体の非特異吸着が起こると,センサの精度は著しく低下することから,高感度測定は望めない.そのため本研究では,抗体固定ビーズを非特異吸着抑制試薬で被覆する方法及び非特異吸着抑制試薬を被覆したビーズに抗体を固定する方法の2種類の方法を用いて,非特異吸着の抑制を試みている.前者では,3種類の非特異吸着抑制試薬を用いて行ったが,いずれの場合においても非特異吸着を十分に抑制することはできなかった.一方,後者では牛血清アルブミン(BSA)と新規に合成したポリマー(poly-3AAm1BA)の2種類について行ったが,BSAでは,十分な効果が見られなかったが,poly-3AAm1BAを用いることにより,非特異吸着は抑制され,同時にセンサの高感度化も実現した.またこのセンサは5回の繰り返し測定が可能であった.
Development of reactor/detector divided amperometric immunosensing system,
53th International Society of Electrochemstry Meeting, Duesseldorf, Germany, Sep. 2002.- (要約)
- 抗原抗体反応を用いた免疫センサは,超極微少濃度測定が期待できる一方,1サンプルごとに,高価な抗体を一定量使用するため,抗体の再生·再使用が可能なセンサの開発が望まれている.従来のアンペロメトリック免疫センサは,電極表面に抗原量に対応した抗原抗体サンドイッチ構造を形成させ,末端に結合した電気化学的活性物質の電気化学的検出を行うというものであり,抗体や抗原は分子量数万のタンパク質であるため,効率的な電気化学的検出には,電導性ワイヤリングを行う等,複雑なシステムが導入する必要があった.そのため抗体の再生·再使用には,抗体の活性低下の問題に加えて,電導性ワイヤリング等の特性変化等,解決すべき課題が多く,困難であった.そのため本研究では,抗体や抗原が反応するリアクターと電気化学検出を行うディテクターとを分離したシステムを導入し,リアクターの再生·再使用が可能なセンシングシステムの構築を試みた.その結果,0.5 % Tween 20 を含む 0.1 M 酢酸溶液を解離溶液に用いることにより,15 回のリアクターの再生が可能であることを見いだした.
In vivo studies of glucose sensors prepared by electropolymerization procedure,
53th International Society of Electrochemstry Meeting, Duesseldorf, Germany, Sep. 2002. Mikito Yasuzawa, Hiroki Takaoka, Shigeru Inoue, Akira Kunugi and Shinji Imai :
Preparation of biocompatible polypyrrole films,
3rd International Conference on Application of Conducting Polymers, Mishima, Japan, Nov. 2001.- (要約)
- ピロール基を有する化合物は,電解酸化を行うことにより,通電を行った特定の部位に均等な重合膜を形成することが可能である.そのため機能性表面修飾法としても興味深い.近年,リン脂質の一つであるホスファチジルコリンの極性部を持つポリマーは,優秀な生体適合性(血液適合性)を有することから,バイオマテリアルとして注目されている.また糖鎖等の親水性表面を有する材料もまた生体適合性材料として機能することが報告されている.そこで本研究では,ピロール基のN-置換基末端にホスファチジルコリンの極性部や糖鎖,カルボキシル基等種々の官能基を有するモノマーの合成を行い,その電解酸化重合を行った.そして得られたポリマーの生体適合性評価を行うため,富血小板吸着試験を行った.その結果ホスファチジルコリンの極性部をピロール基のN-置換基末端に有するピロール誘導体の重合により得られるポリマーが最も高い生体適合性(血液適合性)を示した.糖鎖を有するピロール誘導体のポリマーも良好な生体適合性を示した.
Properties of needle type glucose sensors prepared by the electropolymerization of pyrrole derivatives containing saccharide units,
ICAS 2001, Tokyo, Japan, Aug. 2001. Mikito Yasuzawa, Keisuke Oga, Hikari Mitsui, Hiroyuki Hamada and Akira Kunugi :
Properties of transferrin immunosensors using ferrocene polymer-labeled antibodies,
ICAS 2001, Tokyo, Japan, Aug. 2001. Tetsuya Yamada, Michiru Hara, Mikito Yasuzawa, Akira Kunugi and Shinji Imai :
Properties of glucose sensors based on the immobilization of enzyme in hemocompatibile polypyrrole,
2000 International Chemical Congress of Pacific Basin Societies, Honolulu, Hawaii, USA, Dec. 2000. Mikito Yasuzawa, Shinji Fujii, Hiroki Takaoka, Tetsuya Yamada, Akira Kunugi and Shinji Imai :
Amperometric biosensors based on the immobilization of enzymes by electrochemical polymerization.,
8th International Meeting on Chemical Sensors, Basel, Switzerland, Jul. 2000. Mikito Yasuzawa, Shinji Fujii, Hiroki Takaoka, Tetsuya Yamada, Akira Kunugi and Shinji Imai :
Biosensors based on the immobilization of enzyme in polypyrroles containing gluconyl groups,
6th World Congress on Biosensors, 308, San Diego, California, USA, May 2000.- (要約)
- ピロールやその誘導体を酵素の存在下で電解重合することにより,酵素を電極表面に固定する電解重合法は,酵素を局部的に固定した微小酵素センサを簡単に作製する方法として興味深い.しかしながら,この方法で作製した電極では,酵素は電極表面に形成されたピロールの重合膜に包括的に修飾されているため,十分安定に固定されているとは言えない.そこで本研究では糖鎖を有するピロール誘導体を用いれば,糖鎖が酵素と水素結合を形成することにより,酵素がより強固に固定された酵素固定電極が作製できると考え,ピロールのN-置換基末端に糖鎖を有するピロール誘導体を用い,グルコースオキシダーゼを固定した電極の作製を行った.その結果,グルコースに対して作製直後から4ヶ月以上に渡り,安定した応答電流が得え,応答安定性に優れた電極であることが分かった.また,生体内に存在する電気化学的活性物質の影響を検討したところ,アスコルビン酸,アセトアミノフェン,尿素およびフルクトースの影響はほとんど見られなかったが,尿酸の影響は無視できないものであり,今後の改善が必要であった.
Synthesis and blood compatibility of new grafted polyurethanes containing 2-(methacrylorloxy) ethyl-2-(trimethyllammonium) ethyl phosphate,
6th World Biomaterials Congress, Kamuela, Hawaii, USA, May 2000. Mikito Yasuzawa, Hikari Mitsui, Takashi Matsuki, Hirofumi Sako and Akira Kunugi :
Development of immunosensors using ferrocene-labeled IgG class antibodies,
International Symposium on Prospects of Bioelectrochemistry in the 21st Century, Kyoto, Japan, Mar. 2000. Mikito Yasuzawa, Tomoyuki Hirano, Masaru Hashimoto, Akira Kunugi and Tadao Nakaya :
Synthesis of segmented polyurethanes having ferrocene moieties,
Procs. of 2nd Inter. Conf. on Advanced Materials Development & Performance, Ed. by I. Nakabayashi and R. Murakami, Vol.2, 624-627, Tokushima, Nov. 1999.- (要約)
- セグメント化したポリウレタンは,優れた強度と生体適合性を有することから,広く人工臓器等,バイオマテリアルとして用いられている.我々は以前,セグメント化ポリウレタンに糖鎖を導入したポリマーの合成を行い,酵素を固定する材料としての応用を試みたところ,酵素が安定に固定できることが分かり,酵素センサ作製材料として有用であることが確認された.一方フェロセンは,グルコースオキシダーゼ等の酵素反応の酸化還元触媒として働くことが知られており,酵素センサへの応用が注目されている.そこで本研究では酵素固定に有効と思われる糖鎖と,電子授受を効率よく行わせることを目的にフェロセンの両方を導入したセグメント化ポリウレタンの合成を行った.また糖鎖の導入効果を確認するため,糖鎖を導入していないフェロセン導入ポリウレタンの合成も行った.その結果,糖鎖の導入は酵素固定には不可欠であることが立証された.しかしながら導入したフェロセンは,酵素と効率よく電子授受を起こらせるまでには至らなかった.
Synthesis and properties of segmented polyurethanes having phosphatidylcholine moieties,
Procs. of 2nd Inter. Conf. on Advanced Materials Development & Performance, Ed. by I. Nakabayashi and R. Murakami, Vol.2, 620-623, Tokushima, Nov. 1999.- (要約)
- セグメント化したポリウレタンは,優れた強度と生体適合性を有することから,広く生体材料として用いられており,生体内に埋込,体内物質のリアルタイム測定を行うセンサの外部膜として有用である.本稿ではポリウレタンの特性を活かし,外部膜だけではなく酵素固定膜としての機能を持ったポリウレタンの合成を行い園評価を行った.そのためホスファチジルコリンの極性に加え,酵素との共有結合形成により強固に固定することが期待できる,N-ヒドロオキシサクシイミドの導入を行った.得られたポリマーの生体適合性を富血小板吸着試験を用い行ったところ,優れた血液適合性を示した.またポリマーを被覆した電極に酵素(グルコースオキシダーゼ)を反応させ,酵素固定電極を作製したところ,良好なセンサ寿命を有するグルコースセンサとして機能することが分かった.
Properties of biosensors based on the immobilization of enzyme in hemocompatible polypyrrole films,
Procs. of 2nd Inter. Conf. on Advanced Materials Development & Performance, Ed. by I. Nakabayashi and R. Murakami, Vol.2, 614-619, Tokushima, Nov. 1999.- (要約)
- ピロール環のN-置換基末端にリン脂質であるホスファチジルコリンの極性部を有するピロール誘導体の電解重合により得られたポリマー膜は,優れた血液適合性を有することが富血小板吸着試験により確認された.酵素(グルコースオキシダーゼ)を導入した電極を用いた場合においても同様の結果が得られたことから,このピロール誘導体を用いた酵素固定電極の作製を行った.その結果,ホスファチジルコリンの極性部とピロール環との間の距離が酵素を固定する能力に影響することが分かった.つまりメチレン鎖の長さが3,5と大きくなると酵素固定膜の安定性は向上し,さらに9,11と大きくすると逆に低下することが分かった.これはホスファチジルコリンの極性部を有するピロールポリマーの電導性に起因すると考えられた.
Synthesis and properties of hemocompatible polypyrrole,
Procs. of 2nd Inter. Conf. on Advanced Materials Development & Performance, Ed. by I. Nakabayashi and R. Murakami, Vol.1, 424-429, Tokushima, Nov. 1999.- (要約)
- ピロール基のN-置換基末端にホスファチジルコリンの極性部を有するモノマーの合成を行い,その電解酸化重合を行った.ピロール基と極性部との間のメチレン鎖の長さを変えたところ,メチレン鎖2から11までポリマー化が可能であった.またメチレン鎖5のピロール誘導体が最も成膜性に優れたポリマーを提供することが分かった.得られたポリマーの生体適合性評価を,富血小板吸着試験を用い行ったところ,いずれも優れた血液適合性を示した.
Properties of glucose sensors prepared by the immobilization of glucose oxidase in polyurethane containing ferrocene moieties,
The 1999 Joint International Meeting, Vol.99-2, 1982, Honolulu, Oct. 1999.- (要約)
- セグメント化したポリウレタンは,優れた強度と生体適合性を有することから,広く生体材料として用いられている.本稿ではグルコースオキシダーゼとの相互作用を持たせることを目的に糖鎖を,また電子授受を効率よく行わせることを目的にフェロセンの両方を導入したセグメント化ポリウレタンの合成を行い,グルコースセンサの作製を行った.糖鎖を導入していないポリウレタンでは,10日間で応答が得られなくなったが,糖鎖の導入により80日間以上に渡り,安定した応答が得られた.ポリウレタンは,生体内に埋め込むセンサの外部膜として用いられることはあるが,ポリウレタンを酵素固定膜として機能させた初めての報告である.
Properties of glucose sensors based on immobilization of glucose oxidase in polypyrrole containing saccharide units,
The 1999 Joint International Meeting, Vol.99-2, 71, Honolulu, Oct. 1999.- (要約)
- ピロール類等の電解重合により酵素固定を行う方法は,簡便に特定の部位に酵素を固定できる方法として興味深い.しかしながら酵素は重合膜中に包括的に固定されているため,酵素固定の安定性向上が課題である.本研究ではグルコースオキシダーゼにはグルコース認識する部位(ホール)が存在し,糖類と水素結合等と相互作用を起こすと考えられることから,ピロール環のN-置換基末端に糖鎖(グルコニル基)を有するピロール誘導体の合成を行い,酵素固定電極の作製に用いた.その結果センサ作製直後から8日間センサ感度の安定したセンサの作製が可能であった.また生体液中に存在する電気化学的活性物質のセンサ応答に対する影響を調べたところ,アスコルビン酸,尿素,フルクトースの影響は見られなかったが,尿酸および解熱剤として良く服用されるアセトアミノフェンに関しては無視できるものではなかった.
Preparation of glucose sensors using the Langmuir-Blodgett technique.,
7th International Meeting on Chemical Sensors, Beijing, China, Jul. 1998. Mikito Yasuzawa, Takashi Nieda, Tomoyuki Hirano and Akira Kunugi :
Properties of glucose sensor based on the immobilization of glucose oxidase in N-substituted polypyrrole film.,
7th International Meeting on Chemical Sensors, Beijing, China, Jul. 1998. Mikito Yasuzawa, Takashi Matsuki, Hikari Mitsui, Akira Kunugi and Tadao Nakaya :
Properties of glucose sensors prepared by the electropolymerization of pyrroles containing phosphatidylcholine (II),
7th International Meeting on Chemical Sensors, Beijing, China, Jul. 1998. 趙 雨濛, 中野 輝一, 倉科 昌, 田端 厚之, 松木 均, 安澤 幹人 :
Preparation of biocompatible surface using a new phosphobetaine monomer,
日本バイオマテリアル学会シンポジウム2024, 2P-002, 2024年10月. 佐藤 優介, 橋本 一輝, 倉科 昌, 永瀬 雅夫, 安澤 幹人 :
タングステンプローブを用いた白金ナノ 電極の作製法の検討,
2023年度日本化学会中国四国支部大会, 2023年11月. 角田 芙美, 玉井 伸岳, 後藤 優樹, 安澤 幹人, 松木 均 :
極性頭部荷電が異なるコリンホスフェート型脂質の有機合成,
2023年度日本化学会中国四国支部大会, 2023年11月. 中野 輝一, 趙 雨濛, 倉科 昌, 松木 均, 安澤 幹人 :
Photo-ATRPを用いた双性イオンポリマーブラシの合成,
2023年度日本化学会中国四国支部大会, 2023年11月. 角田 芙美, 玉井 伸岳, 後藤 優樹, 安澤 幹人, 松木 均 :
荷電状態の異なる極性頭部転置型リン脂質の有機合成,
第37回九州コロイドコロキウム, 2023年11月. 久保 智輝, 四宮 龍星, 倉科 昌, 安澤 幹人 :
三酸化アンチモン粉末の表面改質による疎水性媒体中における分散性の向上,
2022年度日本化学会中国四国支部大会, 2022年11月. 橋本 一輝, 池之上 篤志, 安澤 幹人, 倉科 昌, 永瀬 雅夫 :
FIB-CVD法を用いた安定なナノピラーの作製および細胞挿入の検討,
2022年度日本化学会中国四国支部大会, 2022年11月. 寺内 健, 山本 拓也, 吉川 智也, 倉科 昌, 安澤 幹人 :
キトサンナノファイバーを酵素固定膜として用いた微細針状グルコースセンサの作製とその評価,
2022年度日本化学会中国四国支部大会, 2022年11月. 京川 翔哉, 池田 梨菜, 趙 雨濛, 倉科 昌, 松木 均, 安澤 幹人 :
ホスホリルコリン基を有する新規ポリマーの合成及び生体適合性評価,
2022年度日本化学会中国四国支部大会, 2022年11月. 大前 隆史, 大野 恭秀, 安澤 幹人, 永瀬 雅夫 :
塩酸中におけるSiC上グラフェンFETのpH依存性,
2022年度応用物理学・物理系中国四国支部学術講演会, Gp-1, 2022年7月. Yumeng Zhao, Rina Ikeda, Masashi Kurashina, Hitoshi Matsuki and Mikito Yasuzawa :
Biocompatibility Evaluation of Surafce Prepared Using 2-Methacryloyloxyethyl Choline Phosphate,
13th Annual Meeting of Chugoku/Shikoku Branch in the Biophysical Society of Japan, May 2022. 中尾 俊樹, 後藤 優樹, 倉科 昌, 玉井 伸岳, 安澤 幹人, 松木 均 :
ホスファチジルコリン二重膜におよぼす疎水鎖結合様式の影響,
第59回生物物理学会年会, 2021年11月. 中尾 俊樹, 後藤 優樹, 倉科 昌, 玉井 伸岳, 安澤 幹人, 松木 均 :
グリセロ-スフィンゴ混合型非天然リン脂質の二分子膜相転移,
第35回九州コロイドコロキウム, 2021年9月. 中尾 俊樹, 後藤 優樹, 倉科 昌, 玉井 伸岳, 安澤 幹人, 松木 均 :
モジュール構造変更アナログ脂質の合成と二重膜物性,
日本膜学会第43年会, 2021年6月. 久次米 昭宏, 三木 翼, 倉科 昌, 安澤 幹人 :
生体適合性双性イオンポリマーを用いたコポリマーの作製およびその機能性評価,
日本生物物理学会第12回中国四国支部大会, 2021年5月. Haoyuan Li, Quyen Hong Ho, Masashi Kurashina and Mikito Yasuzawa :
Synthesis of N-glucosylated chitosan nanofiber for boron adsorbent,
12th Annual Meeting of Chugoku/Shikoku Branch in the Biophysical Society of Japan, May 2021. Yumeng Zhao, Toshiki Nakao, Tsubasa MIki, Masashi Kurashina, Hitoshi Matsuki and Mikito Yasuzawa :
Preparation of Biocompatible Surface Using Zwitterionic Polymer,
12th Annual Meeting of Chugoku/Shikoku Branch in the Biophysical Society of Japan, May 2021. Toshiki Nakao, Masaki GOTO, Masashi Kurashina, Nobutake Tamai, Mikito Yasuzawa and Hitoshi Matsuki :
Organic Synthesis and Bilayer Properties of a Sphingolipid Analog, an Amide-Linked Phosphatidylcholine,
12th Annual Meeting of Chugoku/Shikoku Branch in the Biophysical Society of Japan, May 2021. 中尾 俊樹, 後藤 優樹, 倉科 昌, 玉井 伸岳, 安澤 幹人, 松木 均 :
スフィンゴリン脂質類似アミド型リン脂質二重膜の熱的相転移:鎖結合様式の対照的効果,
第56回熱測定討論会, 2020年10月. 中尾 俊樹, 後藤 優樹, 倉科 昌, 玉井 伸岳, 安澤 幹人, 松木 均 :
スフィンゴ脂質類似アミド結合型ホスファチジルコリンの有機合成と二重膜物性,
日本膜学会第42年会, 2020年6月. 仲原 拓弥, 麻植 凌, 南川 丈夫, 田上 周路, 安澤 幹人, 加治佐 平, 山口 堅三, 安井 武史 :
バイオセンシング光コムのためのバイオセンサーの開発,
LED総合フォーラム2020 in 徳島, P-12, 2020年2月. 南川 慶二, 安澤 幹人, 倉科 昌, 荒川 幸弘, 今田 泰嗣, 藤田 眞吾 :
教えることによる学びを活用した高大院連携実験出張講義の実践,
大学教育カンファレンス in 徳島, 2019年12月. 仲原 拓弥, 麻植 凌, 南川 丈夫, 田上 周路, 安澤 幹人, 加治佐 平, 山口 堅三, 安井 武史 :
バイオセンシング光コムのためのファイバーバイオセンサーの作製,
Optics & Photonics Japan 2019, 5aB4, 2019年12月. 近藤 真太朗, 倉科 昌, 安澤 幹人 :
液相剥離グラフェンの配列制御に向けた基板への付着特性の評価,
2019年度日本化学会中国四国支部大会, 2019年11月. 柏原 健太, 安澤 幹人, 倉科 昌 :
プラズマエッチングを用いたフッ素樹脂材料の表面活性化及び親水化,
2019年度日本化学会中国四国支部大会, 2019年11月. 櫻井 春希, 大野 椋介, 倉科 昌, 安澤 幹人, 永瀬 雅夫 :
集束イオンビーム化学気相蒸着(FIB-CVD)法を用いたナノピラーの作製及び細胞挿入の試み,
2019年度日本化学会中国四国支部大会, 2019年11月. 趙 雨濛, 中尾 俊樹, 安澤 幹人, 倉科 昌, 松木 均 :
Evaluation on Nonspecific Adsorption on Modified Silica Surface using 2-Iminobiotin Avidin Interaction,
2019年度日本化学会中国四国支部大会, 2019年11月. 中尾 俊樹, 倉科 昌, 後藤 優樹, 玉井 伸岳, 安澤 幹人, 松木 均 :
アミド結合型ホスファチジルコリンの有機合成および二分子膜相転移評価,
2019年度日本化学会中国四国支部大会, 2019年11月. 仲原 拓弥, 麻植 凌, 南川 丈夫, 安澤 幹人, 加治佐 平, 安井 武史 :
屈折率センシング光コムを用いたバイオセンシングに関する検討,
第80回応用物理学会秋季学術講演会, 20p-E205-6, 2019年9月. HO HONG QUYEN, 森下 雄太, 柴田 和希, 倉科 昌, 安澤 幹人, 平賀 由起, 梶浦 平旭 :
Synthesis of borate adsorbent using chitosan nanofiber,
日本海水学会第70年会, 2019年6月. 南川 慶二, 安澤 幹人, 倉科 昌, 荒川 幸弘, 今田 泰嗣, 光永 健二 :
科学技術コミュニケーション科目による高大院連携およびグローバル教育の試行,
大学教育カンファレンス in 徳島, 2018年12月. 谷口 嘉昭, 三木 翼, 大野 恭秀, 永瀬 雅夫, 荒川 幸弘, 安澤 幹人 :
SiC 上グラフェンFETを用いたアビジン-イミノビオチン相互作用の観測,
第10回「集積化MEMSシンボジウム」, 01am2-C-1-(3pp), 2018年11月.- (キーワード)
- グラフェン (graphene)
Immobilization of Nanocarbons and Prussian Blue by Electrodeposition for Glucose and H2O2 Biosensor Detection,
2018年電気化学秋季大会, 2018年9月. 倉科 昌, 鈴鹿 史明, 安澤 幹人 :
酵素または銅ナノ構造を用いたグルコース酸化電極,
日本海水学会第69年会, 2018年6月. 谷口 嘉昭, 三木 翼, 大野 恭秀, 永瀬 雅夫, 荒川 幸弘, 今田 泰嗣, 南川 慶二, 安澤 幹人 :
イミノビオチン修飾グラフェンによるアビジン吸着特性の pH 制御,
第65回応用物理学会春季学術講演会(応物2018春), No.18a-C202-10, 15-057-(1pp), 2018年3月. 谷口 嘉昭, 三木 翼, 大野 恭秀, 永瀬 雅夫, 荒川 幸弘, 今田 泰嗣, 南川 慶二, 安澤 幹人 :
分子修飾技術を用いたグラフェン表面のタンパク質吸着抑制,
平成 29 年度第 4 回半導体エレクトロニクス部門委員会・講演会, P10-(4pp), 2018年1月. 南川 慶二, 安澤 幹人, 倉科 昌, 荒川 幸弘, 今田 泰嗣, 光永 健二 :
学部生と大学院生のティーチングアシスタントチームによる高大院連携化学実験出張講義,
大学教育カンファレンス in 徳島, 2018年1月. 谷口 嘉昭, 三木 翼, 大野 恭秀, 永瀬 雅夫, 荒川 幸弘, 今田 泰嗣, 南川 慶二, 安澤 幹人 :
ホスホリルコリン修飾グラフェンのタンパク質吸着特性,
第9回「集積化MEMSシンボジウム」, 02am2-B-2-(3pp), 2017年11月. 倉科 昌, 吉岡 真希, Ho Hong Quyen, 安澤 幹人 :
環境親和型材料を用いたリン酸イオンの吸脱着と回収,
第4回海水・生活・化学連携シンポジウム, 2017年10月. 杉岡 賢人, 谷口 嘉昭, 三木 翼, 田原 雅章, 大野 恭秀, 永瀬 雅夫, 荒川 幸弘, 南川 慶二, 今田 泰嗣, 安澤 幹人 :
SiC グラフェンを用いた親水化処理における修飾分子依存性,
第78回応用物理学会秋季学術講演会(応物2017秋), No.8a-C16-16, 15-186-(1pp), 2017年9月. 金井 純子, 日下 一也, 井上 貴文, 久保 智裕, 安澤 幹人, 寺田 賢治, 藤澤 正一郎 :
社会人基礎力育成に向けたプロジェクトマネジメント教育の効果,
平成29年電気学会電子・情報・システム部門大会講演論文集, 355-358, 2017年9月. 谷口 嘉昭, 三木 翼, 大野 恭秀, 永瀬 雅夫, 荒川 幸弘, 今田 泰嗣, 南川 慶二, 安澤 幹人 :
ホスホリルコリン修飾によるグラフェン表面のタンパク質吸着抑制,
電子デバイス研究会(ED), 13, 2017年8月. 倉科 昌, 吉岡 真希, Ho Hong Quyen, 安澤 幹人 :
環境親和型材料を用いたリン酸イオンの吸脱着と回収,
日本海水学会第68年会, 2017年6月. 礒合 俊輔, 日裏 健太郎, 丹波 萌, 倉科 昌, 安澤 幹人 :
電解析出法を用いたグルコース オキシターゼ固定電極の作製,
第61回化学センサ研究発表会, 2017年3月.- (要約)
- Glucose oxidase (GOx)-immobilized electrodes were prepared by the combination of electrodeposition and photopolymerization. Methacryloyl choline chloride (NMA) were employed as photo-polymeriable methacrylates and were added in the enzyme- electrdeposition solution, in order to be entrapped in the enzyme film. In order to investigate the enzyme film formation behavior during the electrodeposition process, quartz crystal microbalance (QCM) technique was employed. QCM measurement results indicated that the amount of deposit increased continuously up to around 15 minutes, while the decrease of deposit was observed after that time. The amount of GOx immobilized on the electrode was also measured using Amplex Red Assay Kit and showed that the decrease of deposit was parallel with the decrease of GOx on the electrode. However, the amount of enzyme on the electrode started to increase again after electrodeposition time of 40 minutes. The glucose sensor sensitivity of the obtained electrode showed a good correlation with the amount of enzyme immobilized on the electrode.
SiC 上グラフェンの電気特性評価,
電気化学会第84回大会, 2017年3月. 谷口 嘉昭, 三木 翼, 光野 琢仁, 大野 恭秀, 永瀬 雅夫, 南川 慶二, 安澤 幹人 :
分子修飾機能化による SiC 上グラフェンの非特異吸着の抑制,
第64回応用物理学会春季学術講演会(応物2017春), No.15a-B6-7, 15-085-(1pp), 2017年3月. 南川 慶二, 安澤 幹人, 倉科 昌, 荒川 幸弘, 今田 泰嗣, 藤田 眞吾 :
化学実験出張講義への外国人研究者・留学生の参加―グローバル化を目指した高大連携,
大学教育カンファレンス in 徳島, 46-47, 2016年12月. 金井 純子, 森本 恵美, 井上 貴文, 佐々木 千鶴, 北岡 和義, 日下 一也, 浮田 浩行, 岡本 敏弘, 岸本 豊, 出口 祥啓, 久保 智裕, 安澤 幹人, 寺田 賢治, 藤澤 正一郎 :
学生の自己能力評価アンケート調査からみたイノベーション教育の課題,
大学教育カンファレンスin徳島, 2016年12月. 上原 健志, 安澤 幹人 :
セルロースナノファイバーを固定膜に用いた酵素電極の作製と評価,
2016年度 第3回関西電気化学研究会, 2016年12月. 三木 翼, 荒川 幸弘, 南川 慶二, 安澤 幹人, 今田 泰嗣 :
ホスホリルコリン基を有するピレン誘導体の合成,
2016年日本化学会中国四国支部大会, 2016年11月. 谷口 嘉昭, 三木 翼, 光野 琢仁, 大野 恭秀, 永瀬 雅夫, 南川 慶二, 安澤 幹人 :
新規合成分子を用いた表面修飾による単結晶グラフェンの親水化,
第8回集積化MEMSシンボジウム, No.25pm4-PM-017, 2016年10月. 橋本 直哉, 髙栁 俊夫, 安澤 幹人, 薮谷 智規 :
イオンクロマトグラフィーによるフッ化水素酸とヘキサフルオロケイ酸の同時定量,
第76回 分析化学討論会, 2016年5月. 内丸 正宏, 日裏 健太郎, 安澤 幹人, 渕脇 雄介 :
電解析出法を用いたグルコースオキシダーゼ固定電極の作製及びそのセンサ特性評価,
電気化学会第83回大会, 2016年3月. 礒合 俊輔, 安澤 幹人 :
セルロースナノファイバーを用いて酵素固定したグルコースセンサの作製およびその評価,
電気化学会第83回大会, 2016年3月. 李 江, 安澤 幹人, 渕脇 雄介 :
A patch type biosensor for low-invasive continuous glucose monitoring,
第60回化学センサ研究発表会, 2016年3月.- (要約)
- A low invasive type glucose sensor, which has sensing region at the tip of a fine pointed electrode, was developed for continuous glucose monitoring. Electrodeposition of glucose oxidase in the presence of surfactant, Triton X-100, was performed for high-density enzyme immobilization, and was followed by the electropolymerization of o-phenylene- diamine for the formation of functional entrapping and permselective polymer membrane. Ag/AgCl film was coated on the surface of PEEK tubing as reference electrode. The prepared electrode showed the sensitivity of 2.55 mA/cm2 mM with high linearity of 0.9986, within the glucose concentration range up to 21 mM. The detection limit (S/N = 3) was determined to be 0.11 mM. The glucose sensor properties were evaluated in phosphate buffer solution and in vivo monitoring by the implantation of the sensors in rabbit, while conventional needle-type sensors as a reference were used. The results showed that change in output current of the proposed sensor fluctuated similar with one in output current of the conventional needle-type sensors, which was also in similar accordance with actual blood sugar level measured by commercially glucose meter.
中学・高校への化学実験出張講義におけるティーチングアシスタントの役割と継続的改善,
大学教育カンファレンス in 徳島, 2016年1月. 石坂 森一郎, 荒川 幸弘, 南川 慶二, 今田 泰嗣, 安澤 幹人, 田中 正己 :
リン脂質類似双性イオン側鎖を持つポリマーの合成,
エレクロトレオロジー研究会第35回例会, 2015年12月. 安澤 幹人, 日裏 健太郎, 田上 晃將, 李 江 :
電解析出法を用いたグルコースオキシダーゼ固定電極の作製およびそのグルコースセンサ特性評価,
第61回ポーラログラフィーおよび電気分析化学討論会, 2015年11月. 棚次 悠介, 安澤 幹人, 游 家齊, 朱 瑾 :
金属ガラス薄膜の医療材料への応用及びその評価,
第37回日本バイオマテリアル学会大会, 2015年11月. 渡邉 知也, 荒川 幸弘, 南川 慶二, 今田 泰嗣, 安澤 幹人, 田中 正己 :
フルオレン構造を有する環状リン酸エステルの合成と重合,
第30回中国四国地区高分子若手研究会 「高分子科学のいま,これから」, 2015年11月. 渡邉 知也, 荒川 幸弘, 南川 慶二, 今田 泰嗣, 安澤 幹人, 田中 正己 :
フルオレン構造を有する環状リン酸エステルの合成及びその開環重合によるフィルム形成,
プラスチック成形加工学会第23回秋季大会成形加工シンポジア'15, 2015年11月. 内丸 正宏, 安澤 幹人, 渕脇 雄介 :
電解析出法と電解重合法を組み合わせた カーボンナノチューブ酵素固定電極の作製およびその評価,
2015年電気化学秋季大会, 2015年9月. 安澤 幹人, 李 江, 渕脇 雄介, 田中 正人 :
体内グルコースモニタリング用低侵襲型センサの作製およびその評価,
第59回化学センサ研究発表会, 2015年9月.- (要約)
- A fine needle type glucose sensor, which has sensing region on the tip of a fine tapered electrode, was prepared using tapered PEEK tube with platinum-iridium alloy wire. Glucose oxidase was immobilized on the surface of Pt-Ir electrode using the combination of electrodeposition and electropolymerization procedures. The obtained sensor showed good response with sufficient linear relationship between response current and glucose concentration. Long-term stability of the obtained electrode was evaluated for 35 days. After initial change of response current for a week, constant response current was obtained for 1 month and approximately 80% of the initial sensor response remained. In vivo measurement evaluation of the electrode was performed using rabbit. Considerable glucose sensor response change due to the trend of glucose concentration was observed.
地域地域における実際の問題を解決するにおける実際の問題を解決する企画設計実習の取り組み,
第63回工学教育研究講演会講演論文集, 2A06_1-2, 2015年9月.- (キーワード)
- 導入教育 / 企画設計 / グループ活動
セルロース水溶液を用いた酵素固定電極の作製,
第58回化学センサ研究発表会, 2015年3月. 李 江, 日裏 健太郎, 安澤 幹人, 渕脇 雄介, 田中 正人 :
低侵襲型グルコースセンサの作製及びその特性評価,
電気化学会第82回大会, 2015年3月. 関 基, 中西 信介, 安澤 幹人, 渕脇 雄介 :
ペルヒドロポリシラザンを用いた 機能性表面の作製,
第3回日本バイオマテリアル学会中四国シンポジウム, 2015年1月. 日裏 健太郎, 李 江, 渕脇 雄介, 安澤 幹人 :
電解析出法と光重合法を組み合わせた酵素固定電極の作製およびそのセンサ特性評価,
第3回日本バイオマテリアル学会中四国シンポジウム, 2015年1月. 南川 慶二, 安澤 幹人, 荒川 幸弘, 今田 泰嗣, 藤田 眞吾 :
ティーチングアシスタントを主体とする高大院連携化学実験の実践と評価,
大学教育カンファレンス in 徳島, 2014年12月. 日裏 健太郎, 李 江, 渕脇 雄介, 安澤 幹人 :
電解析出法および光重合法を用いたグルコースオキシダーゼ固定電極の作製及びその評価,
2014年度第3回関西電気化学研究会, 2014年12月. 安澤 幹人, 三川 純平, 李 江, 日裏 健太郎, 渕脇 雄介 :
セルロース分散液を用いた酵素固定膜の作製およびそのセンサへの応用,
第57回化学センサ研究発表会, 2014年9月.- (要約)
- Biorecognition elements, such as enzyme and antibody, were immobilized on Pt-Ir wire electrode by the combination of electrodeposition and photopolymerization. Glucose oxidase was employed as enzyme and glucose sensor properties of obtained GOx-immobilized electrode were investigated. Sensor sensitivity was significantly influenced by the procedure to prepare electrolytic solution for enzyme electrodeposition, which was considered to be due to the difference in enzyme dispersibility in solution. Methacrylates with functional group, such as epoxy and quaternary amine, were also used beside hexyl methacrylate and hexandiol dimethacrylate, in order to introduce interaction between enzyme and entrapping polymer film.
電解析出法を用いた生体識別素子固定電極の作製及びそのセンサへの応用,
第56回化学センサ研究発表会, 2014年3月.- (要約)
- Biorecognition elements, such as enzyme and antibody, were immobilized on Pt-Ir wire electrode by the combination of electrodeposition and photopolymerization. Glucose oxidase was employed as enzyme and glucose sensor properties of obtained GOx-immobilized electrode were investigated. Sensor sensitivity was significantly influenced by the procedure to prepare electrolytic solution for enzyme electrodeposition, which was considered to be due to the difference in enzyme dispersibility in solution. Methacrylates with functional group, such as epoxy and quaternary amine, were also used beside hexyl methacrylate and hexandiol dimethacrylate, in order to introduce interaction between enzyme and entrapping polymer film.
体内グルコースモニタリング用パッチタイプセンサの試作及びその評価,
電気化学会第81回大会, 2014年3月. 南川 慶二, 安澤 幹人, 今田 泰嗣, 藤田 眞吾 :
化学実験出張講義および体験イベントにおける高大院連携の試み,
大学教育カンファレンス in 徳島, 2013年12月. 中西 信介, 田中 秀憲, 棚次 悠介, 安澤 幹人 :
ペルヒドロキシポリシラザンを用いた機能性薄膜の形成およびその評価,
第35回日本バイオマテリアル学会大会, 2013年11月. 佐藤 毅尚, 枝川 和明, 安澤 幹人 :
酸化グラフェンを用いたグルコースセンサの作製およびその評価,
第35回日本バイオマテリアル学会大会, 2013年11月. 鳥羽 威人, 枝川 和明, 安澤 幹人, 渕脇 雄介 :
マイクログルコースセンサの作製およびその評価,
第35回日本バイオマテリアル学会大会, 2013年11月. 枝川 和明, 安澤 幹人 :
リアルタイム血糖モニタリングを目的とした血管内留置用微細針型グルコースセンサの開発,
2013年日本化学会中国四国支部大会, 2013年11月. 安澤 幹人, 李 江, 枝川 和明 :
低侵襲型グルコースセンサの作製及びその評価,
第55回化学センサ研究発表会, 2013年9月. 日裏 健太郎, 枝川 和明, 安澤 幹人 :
電解析出法および光重合法を組み合わせた酵素固定電極の作製,
第55回化学センサ研究発表会, 2013年9月. 渡邊 敏夫, 中野 祥孝, 山田 洋平, 薮谷 智規, 安澤 幹人, 髙栁 俊夫 :
グルコースオキシダーゼの電解析出に対する電極表面の疎水性効果,
日本分析化学会第62年会, 2013年9月. 南川 慶二, 安澤 幹人, 今田 泰嗣, 藤田 眞吾 :
高大院連携化学実験講座による環境教育,
日本エネルギー環境教育学会第8回全国大会論文集, 126-127, 2013年8月. 枝川 和明, 安澤 幹人 :
微細針状グルコースセンサを用いた血管内グルコースモニタリング,
第54回化学センサ研究発表会, 2013年3月. 日裏 健太郎, 古川 晋也, 枝川 和明, 安澤 幹人 :
電解析出法を用いた酵素固定電極の作製及びその評価,
電気化学会創立第80周年記念大会, 2013年3月. 佐藤 文彬, 鳥羽 威人, 南川 慶二, 安澤 幹人, 今田 泰嗣, 藤田 眞吾 :
高校化学実験ティーチングアシスタントを通した創造的学習と 高大院連携教育へのフィードバック,
大学教育カンファレンス in 徳島, 2012年12月. 南川 慶二, 安澤 幹人, 今田 泰嗣, 藤田 眞吾 :
化学実験出張講義における高大院連携教育の効果,
大学教育カンファレンス in 徳島, 2012年12月. 枝川 和明, 安澤 幹人 :
血管内留置型微細針状グルコースセンサの作製及びその評価,
2012年度第3回関西電気化学研究会, 2012年12月. 渡邊 敏夫, 山田 洋平, 薮谷 智規, 安澤 幹人, 髙栁 俊夫, 本仲 純子, 櫻庭 春彦 :
酵素の電解析出に対するナノ粒子の効果およびそのバイオ電池作製への適用,
第58回ポーラログラフィーおよび電気分析化学討論会, 2012年11月. 渡邊 敏夫, 山田 洋平, 薮谷 智規, 安澤 幹人, 髙栁 俊夫, 本仲 純子, 櫻庭 春彦 :
電解析出法による耐熱性酵素CotAの固定化とそれに及ぼすナノ材料の効果,
日本分析化学会第61年会, 280, 2012年9月. Thuy Thi Xuan Le, 薮谷 智規, 髙栁 俊夫, 安澤 幹人 :
γ-ポリグルタミン酸を用いる活性炭微粒子の浮遊回収,
第72回分析化学討論会, 102, 2012年5月. 渡邊 敏夫, 山田 洋平, 薮谷 智規, 安澤 幹人, 髙栁 俊夫, 本仲 純子, 櫻庭 春彦 :
耐熱性酵素の電気化学的析出条件の検討およびそのバイオ電池作製への適用,
電気化学会第79回大会, 2012年3月. 安澤 幹人, 田中 秀憲, 前田 和希, 枝川 和明, 池端 潔人, 野本 信一, 力武 浩太郎, 小出 崇志 :
ペルヒドロポリシラザンを用いた基材表面への生体適合性薄膜形成,
第33回日本バイオマテリアル学会大会, 2011年11月. 枝川 和明, 安澤 幹人 :
インビボ測定用微細針状グルコースセンサの作製 及びその生体適合性の向上,
第33回日本バイオマテリアル学会大会, 2011年11月. 渡邊 敏夫, 山田 洋平, 薮谷 智規, 安澤 幹人, 本仲 純子, 櫻庭 春彦 :
BOD活性を有する耐熱性酵素Bacillus subtilis CotAの電析による固定化とその応用,
2011年日本化学会西日本大会, 178, 2011年11月. 前田 和希, 田中 秀憲, 安澤 幹人 :
ペルヒドロポリシラザンを用いたメタクリレート基を有する表面の作製,
2011年日本化学会西日本大会, 2011年11月. 田中 秀憲, 安澤 幹人 :
ペルヒドロポリシラザンを用いて作製した撥水性表面の安定性評価,
2011年日本化学会西日本大会, 2011年11月. 佐藤 毅尚, 佐藤 文香, 中川 大輔, Le Thi Xuan Thuy, 薮谷 智規, 安澤 幹人 :
磁性を有する凝集剤を用いた水中セシウムおよびストロンチウムの回収,
2011年日本化学会西日本大会, 117, 2011年11月. 安澤 幹人, 横田 清夏, 枝川 和明 :
白金被覆PETフイルム電極の作製およびそのグルコースセンサへの応用,
第52回化学センサ研究発表会, Vol.2011-B, 80-82, 2011年9月.- (要約)
- In order to improve the stability of Pt thin film electrode prepared on the surface of polyethylene terephthalate (PET) film, three types of binder, Nafion, polyethylene imine (PEI) and silica formed from perhydropolysilazane (PHPZ), were introduced on the surface of PET film prior to Pt sputtering. The strength and stability of obtained Pt-coated PET electrodes were evaluated by pencil scratch test and the observation of surface after 40℃ water immersion test. By the use of Nafion and PEI, both pencil scratch hardness and stability in water improved compared with that without the binder, while silica did not perform as a useful binder. Glucose oxidase (GOx) was immobilized on the surface of Pt-coated PET electrodes using electrodeposition and electropolymerization technique and their glucose sensor properties were examined. Glucose sensors prepared using Nafion and PEI as binder provided good response to glucose while the background current were somewhat high. Althoug! h the glucose sensor prepared using Nafion as binder showed poor response after 20 days of use, the sensor with PEI binder provided clear glucose response with lowered background current.
ペルヒドロポリシラザンを用いた微小凹凸表面を有する薄膜形成,
2010年日本化学会西日本大会, 2010年11月. 中西 弘, 枝川 和明, 安澤 幹人 :
微細針状ラクテートセンサの作製及びその評価, 2010年日本化学会西日本大会,
2010年日本化学会西日本大会, 2010年11月. 枝川 和明, 安澤 幹人 :
フレキシブルステンレスワイヤを用いたグルコースセンサの作製およびそのセンサ特性評価,
2010年日本化学会西日本大会, 2010年11月. 芝 直生, 枝川 和明, 安澤 幹人, 玉井 伸岳, 松木 均 :
微小領域のモニタリングを目的としたマイクロバイオセンサの試作及びその評価,
2010年日本化学会西日本大会, 2010年11月. 田中 秀憲, 安澤 幹人 :
ペルヒドロポリシラザンを用いたアルコール類のシリカ表面修飾およびその安定性評価,
2010年日本化学会西日本大会, 2010年11月. 北村 優人, 安澤 幹人 :
生分解性高分子を用いた凝集剤の合成及び水質浄化への応用,
2010年日本化学会西日本大会, 2010年11月. 橋本 智弘, Le Thi Xuan Thuy, 安澤 幹人, 林 由佳子, 本仲 純子, 薮谷 智規 :
アミドキシム基修飾活性炭の合成とその金属吸着挙動,
日本分析化学化学会第59年会, 2010年9月. 張 娟, Le Thi Xuan Thuy, 篠原 達也, 薮谷 智規, 鄧 慧萍, 林 由佳子, 本仲 純子, 安澤 幹人 :
γーポリグルタミン酸修飾磁性粒子による水圏試料中金属イオンの回収,
第68回日本分析化学討論会, 2010年5月. 安澤 幹人, 西村 勇哉, 枝川 和明, 高岡 宏樹 :
先端内部をセンシング部位とする低侵襲型グルコースセンサの試作およびその評価,
第49回化学センサ研究発表会, 2010年3月.- (要約)
- A unique needle type glucose sensor having sensing region inside the tip of a fine tube was fabricated using a sharpen platinum tube. The enzyme glucose oxidase was immobilized on the platinum surface located inside the tip of a fine tube by two step. Firstly, formation of the enzyme monolayer by the electrodeposition of enzyme in the presence of Triton-X, and secondary, electropolymerization of o-phenylenediamine. Amperometric responses of the prepared electrodes to glucose were examined by measuring the electrooxidation current at a potential of 0.60 V (for hydrogen peroxide detection) in 0.1 mol dm-3 phosphate buffer solution (pH 7.4). The obtained sensor showed good response with good linear relationship with glucose concentration up to 18 mmol dm-3. Although the influence of ascorbic acid and acetaminophen to the glucose response current were relatively low, the influence of uric acid was not neglectable.
先端内部をセンシング部位とする低侵襲型グルコースセンサの試作およびその評価,
第49回化学センサ研究発表会, Vol.2010-A, 115-117, 2010年3月.- (要約)
- A unique needle type glucose sensor having sensing region inside the tip of a fine tube was fabricated using a sharpen platinum tube. The enzyme glucose oxidase was immobilized on the platinum surface located inside the tip of a fine tube by two step. Firstly, formation of the enzyme monolayer by the electrodeposition of enzyme in the presence of Triton-X, and secondary, electropolymerization of o-phenylenediamine. Amperometric responses of the prepared electrodes to glucose were examined by measuring the electrooxidation current at a potential of 0.60 V (for hydrogen peroxide detection) in 0.1 mol dm-3 phosphate buffer solution (pH 7.4). The obtained sensor showed good response with good linear relationship with glucose concentration up to 18 mmol dm-3. Although the influence of ascorbic acid and acetaminophen to the glucose response current were relatively low, the influence of uric acid was not neglectable.
バイオセンサを用いた体内物質リアルタイムモニタリングの実用化・普及に向けた課題,
第55回ポーラログラフィー及び電気分析化学討論会, 2009年11月. 西村 勇哉, 山本 美穂, 安澤 幹人 :
微細円筒先端内部をセンシング部位とするグルコースセンサの作製およびその評価,
第55回ポーラログラフィー及び電気分析化学討論会, 2009年11月. 枝川 和明, 松永 卓也, 高岡 宏樹, 安澤 幹人 :
γーポリグルタミン酸を透過選択性膜および酵素固定膜に用いた微細針状グルコースセンサの作製,
第55回ポーラログラフィー及び電気分析化学討論会, 2009年11月. 橋本 智弘, 薮谷 智規, 林 由佳子, 安澤 幹人, 本仲 純子 :
アミドキシム基修飾黒鉛粒子の合成とその分析化学的応用,
2009年日本化学会西日本大会, Vol.1, 152, 2009年11月. 橋本 智弘, 林 由佳子, 薮谷 智規, 安澤 幹人, 本仲 純子 :
炭素粒子表面へのアミドキシム基の導入,
第15回分析化学若手セミナー, 2009年8月. 長岡 正尚, 野本 信一, 安澤 幹人 :
ペルヒドロポリシラザンを用いた撥水性薄膜形成技術の開発(II),
2008年日本化学会西日本大会, 2008年11月. 池端 潔人, 小出 崇志, 高岡 宏樹, 安澤 幹人 :
極性を有するシリカ薄膜形成による生体適合性表面の作製,
2008年日本化学会西日本大会, 2008年11月. 西村 勇哉, 高岡 宏樹, 安澤 幹人 :
マイクロテーパー針を用いた低侵襲測定用グルコースセンサの開発,
2008年日本化学会西日本大会, 2008年11月. 武部 悠一郎, 安澤 幹人 :
免疫センサにおける非特異吸着の抑制,
2008年日本化学会西日本大会, 2008年11月. 安澤 幹人, 枝川 和明, 高岡 宏樹 :
γーポリグルタミン酸を用いた微細針状グルコースセンサの作製,
第46回化学センサ研究発表会, 2008年9月. 長岡 正尚, 野本 信一, 安澤 幹人 :
ペルヒドロポリシラザンを用いた撥水性薄膜形成技術の開発,
2007年日本化学会西日本大会, 2007年11月. 池端 潔人, 野本 信一, 小出 崇志, 安澤 幹人 :
ペルヒドロポリシラザンを用いた生体適合性薄膜形成技術の開発,
2007年日本化学会西日本大会, 2007年11月. 武部 悠一郎, 二神 規通, 山本 昇司, 新居 厚子, 林 修三, 安澤 幹人 :
抗原抗体反応を用いたダイオキシン類簡易測定システムの開発,
2007年日本化学会西日本大会, 2007年11月. 松元 一気, 小川 正弘, 岡田 秀也, 市橋 誠, 安澤 幹人 :
磁性を持った生分解性凝集剤の開発,
2007年日本化学会西日本大会, 2007年11月. 安澤 幹人, 山本 美穂, 森山 健史, 高岡 宏樹 :
低侵襲針状酵素センサの作製およびその評価,
第44回化学センサ研究発表会, Vol.2007-B, 106-108, 2007年9月.- (要約)
- A unique needle type glucose sensor which can be used by inserting only the tip of the sensor in the sample was fabricated. In order to maintain enough area for enzyme immobilization and platinum electrode surface, a cave with platinum surface was formed at the tip of the sensor. The enzyme glucose oxidase was immobilized on the platinum surface located in the cave by the combination of electrodeposition and electropolymerization of o-phenylenediamine. Amperometric responses of the prepared electrodes to glucose were examined by measuring the electrooxidation current at a potential of 0.60 V (for hydrogen peroxide detection) in 0.1 mol dm-3 phosphate buffer solution (pH 7.4). The obtained sensor showed good response with good linear relationship with glucose concentration up to 24 mmol dm-3, which is actually wider than general sensor with sensing part outside of the electrode. This may due to the effective reproduction of oxygen generated by the electrooxidation of hydrogen peroxide, which all occurred in the cave. The application of this sensor to a low invasive glucose sensor fabrication is highly feasible.
ペルヒドロポリシラザンを用いたタンパク質吸着抑制表面形成技術の開発,
第42回化学センサ研究発表会, Vol.2006-B, 13-15, 2006年9月.- (要約)
- Hydrophilic surface modification was performed on glass and stainless plate using perhydropolysilazane (PZ) and polyethylene glycol (PEG). The water contact angle was lower on the surface prepared using higher molecular weight PEG. Although, the introduction of monoalkoxy PEG to the surface of silica was performed without any matter, dialkoxy PEG did not react with PZ and silica film without PEG was obtained on the surface. Molar ratio of protein adsorption of fibrinogen to albumin (F/A molar ratio), which was adopted as the indicator of biocompatibility, was measured. The F/A molar ratio was lowered by the surface modification of PEG. PEG surface modification contributed to improve the biocompatibility.
微細針状マルチチャンネルセンサ作製を目的とした微小領域への選択的酵素固定技術の開発,
第42回化学センサ研究発表会, Vol.2006-B, 10-12, 2006年9月.- (要約)
- In the development of in vivotype glucose sensor, miniaturization of the sensor size and flexibility is quite importance to reduce damage to the tissue from sensor implantation.Super flexible Ni-Ti alloy wire with a diameter of 100mm was applied as a core material in order to obtain fine and flexible sensor. Gold plating and platinum plating were performed on Ni-Ti wire to obtain sensing region with platinum surface and was applied for glucose sensor. Pt sensing region prepared on Au plated Ni-Ti presented good response to hydrogen peroxide and the applied glucose sensor also showed good response to glucose. Back ground current and current noise were significantly lower than that prepared from Pt sputtering on Ni-Ti wire.
超弾性合金を芯材に用いた体内埋め込み測定用バイオセンサの作製,
第42回化学センサ研究発表会, Vol.2006-B, 7-9, 2006年9月.- (要約)
- In the development of in vivotype glucose sensor, miniaturization of the sensor size and flexibility is quite importance to reduce damage to the tissue from sensor implantation.Super flexible Ni-Ti alloy wire with a diameter of 100mm was applied as a core material in order to obtain fine and flexible sensor. Gold plating and platinum plating were performed on Ni-Ti wire to obtain sensing region with platinum surface and was applied for glucose sensor. Pt sensing region prepared on Au plated Ni-Ti presented good response to hydrogen peroxide and the applied glucose sensor also showed good response to glucose. Back ground current and current noise were significantly lower than that prepared from Pt sputtering on Ni-Ti wire.
γ(ポリグルタミン酸)誘導体の合成と性質,
第55回高分子学会年次大会, Vol.2006-B, 2335, 2006年5月.- (要約)
- γ -Polyglutamic acid derivatives containing amino acids in the side chains were synthesized and their properties for cosmetic materials were examined. The derivatives obtained showed good water holding capability and inhibited the adsorption of Staphylococcus aureus to epithelial cells. Aspartic acid containing polyglutamic acid derivatives exhibited the best inhibition for adherence of Pseudomonas aeruginosa to the surface of soft contact lens.
インビボ測定用マルチチャンネルセンサの開発,
第41回化学センサ研究発表会, Vol.2006-A, 115-117, 2006年4月.- (要約)
- Glucose/lactate dual-channel needle type biosensor with the total diameter of less than 250 μm was fabricated by the combination of glucose oxidase (GOx) immobilized tube electrode and lactate oxidase (LOx) immobilized wire type electrode. GOx immobilized tube electrode was prepared by the formation of sensing site on Pt-coated polyimide tube and immobilizing GOx by electrodeposition of GOx followed by electropolymerization of o-phenylenediamine. LOx immobilized wire type electrode was also prepared by first enzyme electrodeposition step and then electopolymerization step. Both GOx immobilized tube electrode and LOx immobilized wire type electrode showed good response and showed good linear response up to 15 mmol dm-3 in both 0.1 mol dm-3 phosphate buffer solution (pH 7.4) and in horse serum. No crosstalk was observed when glucose/lactate dual-channel needle type biosensor was tested in 0.1 mol dm-3 phosphate buffer solution (pH 7.4). In vivo measurement in rats with the dual channel sensors is under investigation.
インビボ測定用フレキシブルグルコースセンサの開発,
第41回化学センサ研究発表会, Vol.2006-A, 112-114, 2006年4月.- (要約)
- Important design considerations for in vivo type glucose sensors include miniaturization and flexibility, specificity, biostability, long useable life span, and safety. In the design of the sensor, miniaturization of the sensor is of primary importance. Miniaturization and flexibility of the sensor will help reduce the damage to the tissue from sensor implantation. Sensors fabricated from small diameter platinum (<0.1mm) can be brittle, therefore create a greater risk of breakage. In this study, flexible super-elastic Ni-Ti alloy wire was used as the core material with platinum thin film sputtered on its surface. A comparison of the sensor performance between platinum wire and platinum sputtered Ni-Ti wire is demonstrated. Glucose oxidase immobilization was performed by crosslinking with glutaraldehyde and bovine serum albumin. The sensor was fablicated with an integral Ag /AgCl reference to facilitate in vivo testing. This in vivo type glucose sensor showed remarkable anti-interferent selectivity, moreover with a linearity range extending up to 22.4 mM in the phosphate buffer solution.
マルチチャンネルセンサ作製を目的とした微小領域への選択的酵素固定,
2005年 電気化学秋季大会, 2005年9月. 高岡 宏樹, 森山 健史, 安澤 幹人, 清水 利泰, 今井 信治, Raeann Gifford, George S. Wilson :
微細針状グルコースセンサを用いた体内グルコース濃度連続測定評価,
第40回化学センサ研究発表会, Vol.21, No.Supplement B, 34-36, 2005年9月.- (要約)
- There are various desirable characteristics to consider when designing in vivo type glucose sensors; including miniaturization, specificity, biostability, long useable life span, and safety. Miniaturization of the sensor is an important feature because smaller devices are less invasive, both physically and psychologically. A miniaturized device will excite fewer pain receptors in the skin and will cause less tissue damage, thus less pain and improved performance. However, since miniaturization can lead to easy deformation and breakage of the sensor, it is difficult to fabricate sensors less than 200 μm diameter that retain enough flexibility and strength to insure proper in vivo function. In this study, super-elastic Ni-Ti alloy wire was used as the core material with platinum thin film sputtered on its surface. Glucose oxidase was then immobilized on the platinum surface and functional glucose sensor characteristics were investigated. In vivo measurement with the new flexible glucose sensor was attempted.
マイクロ針状グルコースセンサの作製,
第40回化学センサ研究発表会, Vol.2005-B, 40-42, 2005年9月.- (要約)
- Glucose sensors with the diameter of less than 10 um were fabricated using super-flexible Ni-Ti alloy wire as a core material. The 150 um diameter of Ni-Ti alloy wire was reduced by a continuous dipping operation in etching solution. Ni-Ti surface was sputter coated with Pt film. The Pt surface was covered with silica leaving the unetched end bare for electric contact. Silica on the etched tip was removed in order to prepare sensing cavity. Glucose oxidase (GOx) was immobilized on the sensing cavity by the electropolymerization of 1-(6-D-gluconamidohexyl) pyrrole (GHP) in the presence of GOx. Performance characteristics of the fabricated micro glucose sensor were determined in phosphate buffered saline (pH 7.4). The response current increased with the increase of glucose concentration up to 22 mmol dm-3. However, the linear range went up to 11 mmol dm-3. The response time to 90% maximum current for the micro glucose sensor was 20 seconds.
生体識別素子固定化ポリマーの合成及びそのセンサへの応用,
2005年 電気化学秋季大会, 2005年9月. 古川 晋也, 安澤 幹人, George S. Wilson :
電解析出法を用いた微細針状酵素センサの作製,
2005年 電気化学秋季大会, 2005年9月. 力武 浩太郎, 小出 崇志, 二神 規通, 古川 晋也, 安澤 幹人 :
非特異吸着抑制表面加工技術の開発,
第39回化学センサ研究発表会, Vol.2005-A, 2005年4月.- (要約)
- The adaptation of metals surface was performed by the surface reaction of perhydropolysilazane (PZ) in the presence of polyethylene glycol (PEG). Surface hydrophilic property was able to control by the reaction of PEG with PZ and the usage of PEG at various molecular weight. Biocompatibility of platinum treated with PZ and PEG was evaluated by blood platelet adhesion test. The treatment significantly improved the biocompatibility of platinum. Potentiality and utility of new surface processing technique for biocompatibility treatment and nonspecific adsorption inhibition was strongly suggested.
バイオセンサ作製用生体識別素子固定ポリマーの合成およびその評価,
2005年(春)電気化学会第72回大会, 2005年4月. 古川 晋也, 安澤 幹人, George S. Wilson :
電解析出法による微細針状酵素センサの作製及びその評価,
2005年(春)電気化学会第72回大会, 2005年4月. 安澤 幹人, 高岡 宏樹, 清水 利泰, 今井 信治, George S. Wilson :
微細針状デバイスを用いたインビボ測定,
第39回化学センサ研究発表会, Vol.21, No.Supplement A, 121-123, 2005年4月.- (要約)
- This study attempts to eliminate the noise signals observed on the response of in vivo glucose measurement due more to operational problem than the sensor properties. Measurement was performed without anesthesia in order to eliminate the influence of anesthetic on blood glucose level. Catheter was inserted into femoral vein for glucose injection and blood sampling for in vitro measurement. Fine needle type sensors were placed in flank adipose tissue, intra-abdominal tissue and veins of the neck and were measured using wired and wireless potentiostat. No noise and spike signals due to the operation of glucose injection and blood sampling were observed by the use of catheter. Clear glucose sensor response with good correlation with in vitro value was able to obtain on all three regions measurement, while time differences existed. The possibilities of successful measurements were lower on intra-abdominal tissue and veins of the neck than that of adipose tissue.
IgGクラスの特異抗体を用いた免疫センサの開発,
第5回徳島地区分析技術研究会, 2001年2月.- (要約)
- 抗体はある特定の物質とのみ結合(特異吸着)する特徴を持っており,この特異性を利用した免疫センサの開発が行われている.本講演では,抗体センサの原理の説明並びに今市販されている妊娠診断薬等や今後の応用が期待されている内分泌攪乱化学物質等の低分子量化合物測定への応用について解説している.
酵素修飾電極の作製法,
酵素工学研究会第31回講演会, 1994年5月.- (要約)
- 酵素センサや酵素リアクター等,酵素を有効にまた容易に繰り返し利用するため,酵素の固相化がよく行われている.特に酵素を電極に固定して作製することが可能な酵素センサは,糖尿病患者の血糖値測定に必要不可欠になっている.本講演では,様々な酵素固定法の特徴およびその主な用途を紹介し,その今後の展開について解説した.
- 研究会・報告書
- Pankaj Koinkar and Mikito Yasuzawa :
Getting Involved in Graduate Research Programs in Japan,
D. Y. Patil College of Engineering, Pune University, Jan. 2019. 永瀬 雅夫, 大野 恭秀, 安澤 幹人 :
集束イオンビーム技術によるナノ電極プローブの開発,
社会産業理工学研究交流会2018, No.No.27, 2018年9月.- (キーワード)
- 集束イオンビーム技術
創成学習開発センターが支援するプロジェクトマネジメント基礎による創造性教育,
教育シンポジウム2017, 2017年3月. 金井 純子, 森本 恵美, 井上 貴文, 丹羽 実輝, 佐々木 千鶴, 日下 一也, 浮田 浩行, 岸本 豊, 出口 祥啓, 久保 智裕, 安澤 幹人, 寺田 賢治, 藤澤 正一郎 :
ものづくり教育による大学生の能力向上,
電気学会研究会資料 制御研究会, No.CT-16-036, 93-95, 2016年3月.- (キーワード)
- ものづくり教育 / 能力向上
徳島大学創成学習開発センターが支援する自主プロジェクト演習による創造性教育,
工学教育シンポジウム2016, 2016年3月. 日下 一也, 貴島 政親, 大西 舞, 森本 恵美, 塚越 雅幸, 安澤 幹人, 玉井 伸岳, 芥川 正武, 寺田 賢治, 藤澤 正一郎 :
導入科目「プロジェクトマネージメント基礎」における企画設計実習の取り組み,
電気学会研究会資料 制御研究会, No.CT-14-87, 25-30, 2014年12月. 日下 一也, 山田 洋平, 大西 舞, 塚越 雅幸, 安澤 幹人, 後藤 優樹, 森本 恵美, 芥川 正武, 寺田 賢治, 藤澤 正一郎 :
導入科目「プロジェクトマネジメント基礎」の実施と評価,
電気学会研究会資料 制御研究会, Vol.CT-14, No.15, 11-16, 2014年4月.- (要約)
- We report about the introductory subject "Project Management Fundamentals". The student will get a basic ability to work with diverse peoples in the community or workplace, through the planning and practice of a project to accomplish the task. In addition, the student will obtain project management skills required to design and implement the project. This year's theme was "the development of new products to eliminate the inconvenience for you". The students worked on the development of new products in a team as a project. We evaluated the individual and team by using the project notes.
- (キーワード)
- 導入科目 / 創成科目 / プロジェクト / プロジェクト管理 (project management) / グループ活動 / 評価 (evaluation)
IN VIVO type Glucose Sensors for Continuous Glucose Monitoring,
Bilateral Research Symposium between the University of Tokushima and the University of Gondar, Mar. 2013. Karlsen Lena, Kimura Keisuke and Mikito Yasuzawa :
Purification of Cesium Polluted Water using Magnetic Flocculant and Adsorbents,
Bilateral Research Symposium between the University of Tokushima and the University of Gondar, Mar. 2013.
- 特許
- 安澤 幹人, 古川 晋也 : 生体用デバイス,生体用デバイスの接触部構造および生体センサ, 特願12/278,829 (2008年8月), 特開US2009/0069654 (2009年3月), . 市橋 誠, 安澤 幹人 : 磁性体凝集剤,その製造方法,及び磁性体凝集剤を用いた水の浄化方法, 特願PCT/JP2008/53580 (2008年2月), 特開WO 2008105521 (2008年9月), . 市橋 誠, 安澤 幹人 : 磁性体凝集剤及び磁性体凝集剤の製造方法, 特願2007-279748 (2007年10月), . 安澤 幹人, 野本 信一 : 撥水処理方法および撥水性シリカ層を有する基材, 特願2007- 78039 (2007年3月), 特開2008-237957 (2008年10月), 特許第5250813(P5250813)号 (2013年7月). 安澤 幹人, 市橋 誠 : 磁性体結合ポリマー製凝集剤及びこれを用いた水の浄化方法, 特願2007-049127 (2007年2月), . 安澤 幹人, 古川 晋也 : 生体用デバイス,生体用デバイスの接触部構造および生体センサ, 特願2007 557887 (2007年2月), 特開WO2007/091633 (2007年8月), 特許第5162757号 (2012年12月). 安澤 幹人 : マスキング方法, 特願2006-247936 (2006年9月), 特開2008-68188 (2008年3月), . 安澤 幹人, 今井 信治 : 線状デバイス, 特願10/544, 243 (2006年6月), 特開20070088208 (2007年4月), . 中井 史郎, 森 康子, 安澤 幹人 : アミノ酸修飾ー(γーポリグルタミン酸)またはその塩,およびこれらの用途, 特願2006-128657 (2006年5月), 特開2007-297559 (2007年11月), . 安澤 幹人 : 棒状デバイスおよび生体センサ, 特願2006-041358 (2006年2月), . 安澤 幹人, 古川 晋也 : 管状デバイスおよび生体用センサ, 特願2006-032275 (2006年2月), . 安澤 幹人, 小出 崇志 : 基材表面の改質方法,改質された表面を有する基材およびその製造方法, 特願2005-JP23177 (2005年12月), 特開WO2006/064918 (2006年6月), 特許第4117356号 (2008年5月). 安澤 幹人, 小出 崇志 : 基材表面の改質方法および改質された表面を有する基材, 特願2006-548946 (2005年12月), 特開WO2006/064918 (2006年6月), 特許第4117356号 (2008年5月). 安澤 幹人, 今井 信治 : 線状デバイス, 特願WO2004JP01669 (2004年2月), 特開WO2004071294 (2004年8月), 特許第P3894943号 (2006年12月). 安澤 幹人 : 線状デバイス, 特願2003-038609 (2003年2月), . 仲矢 忠雄, 安澤 幹人, 椚 章 : (メタ)アクリル酸系エステル,重合体及び製造方法, 特願09-249138 (1997年9月), 特開平11-80188 (1999年3月), . 仲矢 忠雄, 安澤 幹人, 井本 稔 : 2個の重合活性基を有するリン脂質類似モノマーおよびその製造方法, 特願昭60-46935 (1985年3月), 特開昭61-205291 (1986年9月), . 仲矢 忠雄, 安澤 幹人, 井本 稔 : ポリ(ホスファチジルコリン)の製造方法, 特願昭59-62985 (1984年3月), 特開昭60-206835 (1985年10月), 特許第1788042号. 仲矢 忠雄, 安澤 幹人, 井本 稔 : ポリ脂質類似モノマーの製造方法, 特願昭59-62983 (1984年3月), 特開昭60-204791 (1985年10月), 特許第1788042号. 仲矢 忠雄, 安澤 幹人, 井本 稔 : 薬理活性物質の徐放方法, 特願昭59-62984 (1984年3月), 特開昭60-204711 (1985年10月), 特許第1834891号.
- 作品
- 研究者総覧に該当データはありませんでした。
- 補助金・競争的資金
- 低血糖症の早期発見を目的とした低侵襲パッチ型グルコースセンサの開発 (研究課題/領域番号: 24500510 )
非強酸・非窒素系溶媒を活用した低環境負荷的希少元素リサイクル法の開発 (研究課題/領域番号: 22656207 )
ポリピロール誘導体を包括材料に用いたインビボ型グルコースセンサの開発 (研究課題/領域番号: 08780828 )
ビニル化合物類の電気化学的カルボキシル化に関する研究 (研究課題/領域番号: 63550608 )
研究者番号(70210250)による検索
- その他
- 研究者総覧に該当データはありませんでした。
2024年12月20日更新
- 専門分野・研究分野
- 電気化学 (Electrochemistry)
バイオマテリアル (Biomaterials) - 所属学会・所属協会
- 日本バイオマテリアル学会
公益社団法人 電気化学会
公益社団法人 日本化学会
国際電気化学会
化学センサ研究会
アメリカ電気化学会
日本分析化学会
日本ポーラログラフ学会 - 委員歴・役員歴
- 公益社団法人 電気化学会 (関西支部幹事 [2007年4月〜])
公益社団法人 日本化学会 (中四国支部幹事 [2019年3月〜2021年2月])
化学センサ研究会 (編集委員 [2001年1月〜2013年12月], 役員 [2014年1月〜])
日本ポーラログラフ学会 (評議員 [2011年4月〜]) - 受賞
- 2012年10月, Sensor Division Student Paper Award (アメリカ電気化学会)
2012年11月, 第58回ポーラログラフィーおよび電気分析化学討論会 学生優秀賞 (日本ポーラログラフ学会)
2014年7月, Best Paper Award (The Seventh International Conference on Advanced Materials Development and Performance (AMDP2014))
2014年7月, Best Poster Award (The Seventh International Conference on Advanced Materials Development and Performance (AMDP2014))
2015年3月, Young Researcher Best Presentation Award (2nd International Forum on Advanced Technologies)
2017年7月, Best Poster Award (The 8th International Conference on Advanced Materials Development and Performance (AMDP2017))
2018年3月, Young Researcher Presentation Award (4th International Forum on Advanced Technologies)
2021年6月, 日本膜学会第43年会 学生賞 (日本膜学会)
2021年9月, 第35回九州コロイドコロキウム 優秀ポスター賞 (日本化学会 コロイドおよび界面化学部会 九州支部) - 活動
- 研究者総覧に該当データはありませんでした。
2024年12月22日更新
2024年12月21日更新
Jグローバル
- Jグローバル最終確認日
- 2024/12/21 01:29
- 氏名(漢字)
- 安澤 幹人
- 氏名(フリガナ)
- ヤスザワ ミキト
- 氏名(英字)
- Yasuzawa Mikito
- 所属機関
- 徳島大学 准教授
リサーチマップ
- researchmap最終確認日
- 2024/12/22 02:29
- 氏名(漢字)
- 安澤 幹人
- 氏名(フリガナ)
- ヤスザワ ミキト
- 氏名(英字)
- Yasuzawa Mikito
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- 更新日時
- 2020/5/24 23:11
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2024年12月21日更新
- 研究者番号
- 70210250
- 所属(現在)
- 2024/4/1 : 徳島大学, 大学院社会産業理工学研究部(理工学域), 教授
- 所属(過去の研究課題
情報に基づく)*注記 - 2012/4/1 – 2014/4/1 : 徳島大学, ソシオテクノサイエンス研究部, 准教授
2010/4/1 – 2011/4/1 : 徳島大学, 大学院・ソシオテクノサイエンス研究部, 准教授
1996/4/1 : 徳島大学, 工学部, 助手
1988/4/1 – 1990/4/1 : 徳島大学, 工学部, 助手
- 審査区分/研究分野
-
研究代表者
複合領域 / 医用生体工学・生体材料学
総合・新領域系 / 総合領域 / 人間医工学 / 医用生体工学・生体材料学研究代表者以外
理工系 / 工学 / 総合工学 / リサイクル工学
工学 / 応用化学 / 工業物理化学・複合材料
- キーワード
-
研究代表者
グルコースセンサ / ピロール誘導体 / 電解重合 / 4級アンモニウム塩 / ホスファチジルコリン / ナフィオン / インビトロ測定 / インビボ測定 / CGM / バイオセンサ / 血糖値 / 低侵襲 / 糖尿病 / 低血糖症 / パッチ / 酵素電極 / CGMS
研究代表者以外
レアメタル / 資源回収 / 非強酸 / 非窒素 / キレート / リサイクル / 有機硫黄化合物 / ビニルスルホキシド / ビニルスルホン / 電解還元脱硫反応 / 電気化学的カルボキシル化 / 二酸化炭素の固定化 / Organosulfur Compound / Vinyl Sulfoxide / Vinyl Sulfone / Electroreductive Desulfurization / Electrochemical Carboxylation / Fixation of Carbon Dioxide
研究課題
研究成果
共同研究者