A molecular wire modified glassy carbon electrode for achieving direct electron transfer to native glucose oxidase

被引:100
作者
Liu, Guozhen [1 ]
Paddon-Row, Michael N. [1 ]
Gooding, J. Justin [1 ]
机构
[1] Univ New S Wales, Sch Chem, Sydney, NSW 2052, Australia
基金
澳大利亚研究理事会;
关键词
glucose oxidase; molecular wires; self-assembled monolayers; direct electron transfer;
D O I
10.1016/j.elecom.2007.06.016
中图分类号
O646 [电化学、电解、磁化学];
学科分类号
081704 ;
摘要
Here we describe a strategy for achieving direct electron transfer to native glucose oxidase (GOx), an enzyme in which the redox active centre is buried deep within the glycoprotein. To achieve this a glassy carbon electrode is modified with a mixed monolayer of 4-carboxyphenyl and a 20 angstrom long oligo(phenylethynyl) molecular wire (MW), assembled from the respective aryl diazonium salts. Subsequently GOx is adsorbed to the interface, followed by covalent attachment. The redox chemistry of the active centre of glucose oxidase, flavin adenine dinucleotide, was observed at an E-1/2 of -443 mV (vs. Ag vertical bar AgCl). The enzyme was shown to retain its activity. Most importantly, in the absence of oxygen the electrode was still able to biocatalytically turn over glucose at -400 mV, thereby demonstrating that the enzyme was being recycled back to its catalytically active oxidized form from its inactive reduced form. The rate of enzyme turnover was 1.1 s(-1) (c) 2007 Elsevier B.V. All rights reserved.
引用
收藏
页码:2218 / 2223
页数:6
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