Bon Saint-Côme Y., Lalo H., Wang Z., Etienne M., Gajdzik J., Kohring G-W., Walcarius A., Hempelmann R., Kuhn A.
Langmuir 2011, 27, 12737-12744

We describe the elaboration of a multi-scale tailored bioelectrocatalytic system. The combination of two enzymes, D-sorbitol dehydrogenase (DSDH) and diaphorase (DI) is studied with respect to the oxidation of D-sorbitol as a model system. The biomolecules are immobilized in an electrodeposited paint (EDP) layer. Reproducible and efficient catalysis of D-sorbitol oxidation is recorded when this system is immobilized on a gold electrode modified by a self-assembled monolayer (SAM) of 4-carboxy-(2,5,7-trinitro-9-fluorenylidene)-malonitrile (CTNFM) used as a mediator. The insertion of mediator modified gold nanoparticles (AuNP) in the EDP film increases significantly the active surface area for the catalytic reaction and can be further enhanced when the whole system is immobilized in macroporous gold electrodes. This multi-scale architecture finally leads to a catalytic device with optimized efficiency for potential use in biosensors, bioelectrosynthesis and biofuel cells.