Kinetics of redox polymer-mediated enzyme electrodes

Joshua W. Gallaway, Scott A Calabrese Barton

Research output: Contribution to journalArticle

  • 128 Citations

Abstract

Oxygen-reducing enzyme electrodes are prepared from laccase of Trametes versicolor and a series of osmium-based redox polymer mediators covering a range of redox potentials from 0.11 to 0.85 V. Experimentally obtained current density generated by the film electrodes is analyzed using a one-dimensional numerical model to obtain kinetic parameters. The bimolecular rate constant for mediation is found to vary with mediator redox potential from 250 s-1 M-1 when mediator and enzyme are close in redox potential to 9.4 × 104 s-1 M-1 when the redox potential difference is large. The value of the bimolecular rate constant for the simultaneously occurring laccase-oxygen reaction is found to be 2.4 × 105 s-1 M-1. The relationship between mediator-enzyme overpotential and bimolecular rate constant is used to determine the optimum mediator redox potential for maximum power output of a hypothetical biofuel cell with a planar cathode and a reversible hydrogen anode. For laccase of T. versicolor (Ee0 = 0.82), the optimum mediator potential is 0.66 V (SHE), and a molecular structure is presented to achieve this result.

LanguageEnglish (US)
Pages8527-8536
Number of pages10
JournalJournal of the American Chemical Society
Volume130
Issue number26
DOIs
StatePublished - Jul 2 2008

Profile

Enzyme electrodes
Biosensing Techniques
Oxidation-Reduction
Polymers
Laccase
Kinetics
Rate constants
Electrodes
Enzymes
Bioelectric Energy Sources
Trametes
Biological fuel cells
Oxygen
Osmium
Molecular Structure
Kinetic parameters
Molecular structure
Numerical models
Hydrogen
Anodes

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

Kinetics of redox polymer-mediated enzyme electrodes. / Gallaway, Joshua W.; Barton, Scott A Calabrese.

In: Journal of the American Chemical Society, Vol. 130, No. 26, 02.07.2008, p. 8527-8536.

Research output: Contribution to journalArticle

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