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

Guozhen Liu, Michael N. Paddon-Row, J. Justin Gooding*

*Corresponding author for this work

Research output: Contribution to journalArticle

98 Citations (Scopus)

Abstract

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 Å 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 E1/2 of -443 mV (vs. Ag|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.

Original languageEnglish
Pages (from-to)2218-2223
Number of pages6
JournalElectrochemistry Communications
Volume9
Issue number9
DOIs
Publication statusPublished - Sep 2007
Externally publishedYes

Keywords

  • Direct electron transfer
  • Glucose oxidase
  • Molecular wires
  • Self-assembled monolayers

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