Visualisation of the local bio-electrocatalytic activity in biofuel cell cathodes by means of redox competition scanning electrochemical microscopy (RC-SECM)

Optimisation of biocatalytic systems for the electroreduction of molecular O-2 in biofuel cell cathodes implies screening of the catalytic activity of enzyme/redoxpolymer assemblies. Os-complex modified electrodeposition polymers are suggested for linking bilirubin oxidase catalysed O-2 reduction via an electron hopping sequence along the redox polymer to the electrode. They can be non-manually precipitated on electrode surfaces by electrochemically induced pH modulation. Cyclic voltammetry provides a good estimation of the electrocatalytic activity of a redox polymer/enzyme modified electrode surface. In addition, scanning electrochemical microscopy operating in redox competition mode (RC-SECM) supplies images of the spatial distribution of the biocatalytic activity. (c) 2007 Elsevier B.V. All rights reserved.