Direct electrochemistry and intramolecular electron transfer of ascorbate oxidase confined on l-cysteine self-assembled gold electrode

Bhushan Patil, Yoshiki Kobayashi, Shigenori Fujikawa, Takeyoshi Okajima, Lanqun Mao, Takeo Ohsaka

    研究成果: Contribution to journalArticle査読

    17 被引用数 (Scopus)

    抄録

    A direct electrochemistry and intramolecular electron transfer of multicopper oxidases are of a great importance for the fabrication of these enzyme-based bioelectrochemical-devices. Ascorbate oxidase from Acremonium sp. (ASOM) has been successfully immobilized via a chemisorptive interaction on the l-cysteine self-assembled monolayer modified gold electrode (cys-SAM/AuE). Thermodynamics and kinetics of adsorption of ASOM on the cys-SAM/AuE were studied using cyclic voltammetry.A well-defined redox wave centered at 166±3mV (vs. AgAgClKCl(sat.)) was observed in 5.0mM phosphate buffer solution (pH7.0) at the fabricated ASOM electrode, abbreviated as ASOM/cys-SAM/AuE, confirming a direct electrochemistry, i.e., a direct electron transfer (DET) between ASOM and cys-SAM/AuE. The direct electrochemistry of ASOM was further confirmed by taking into account the chemical oxidation of ascorbic acid (AA) by O2 via an intramolecular electron transfer in the ASOM as well as the electrocatalytic oxidation of AA at the ASOM/cys-SAM/AuE.Thermodynamics and kinetics of the adsorption of ASOM on the cys-SAM/AuE have been elaborated along with its direct electron transfer at the modified electrodes on the basis of its intramolecular electron transfer and electrocatalytic activity towards ascorbic acid oxidation and O2 reduction. ASOM saturated surface area was obtained as 2.41×10-11molcm-2 with the apparent adsorption coefficient of 1.63×106Lmol-1. The ASOM confined on the cys-SAM/AuE possesses its essential enzymatic function.

    本文言語英語
    ページ(範囲)15-22
    ページ数8
    ジャーナルBioelectrochemistry
    95
    DOI
    出版ステータス出版済み - 2 2014

    All Science Journal Classification (ASJC) codes

    • 生物理学
    • 物理化学および理論化学
    • 電気化学

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