High-Surface-Area Three-Dimensional Biofuel Cell Electrode Using Redox-Polymer-Grafted Carbon

A novel biofuel cell electrode has been developed using surface-modified carbon to obtain high current density. Until now, the amount of enzyme effectively used in electrode reactions has been restricted as a result of electron conduction via a redox polymer, which shuttles electrons from the enzyme to the electrode. In the novel electrode described herein, conduction of electrons was divided between a redox polymer and carbon, and thus, the electron conduction distance in the redox polymer was decreased. The redox polymer was chemically immobilized onto a carbon black surface using a graft polymerization method. Using this modified carbon black, a three-dimensional carbon electrode containing the enzymes was fabricated. The electrode was employed as a glucose-oxidizing anode, using glucose oxidase as the enzyme and a poly(vinylferrocene-co-acrylamide) as the redox polymer. Cyclic voltammetry showed that the glucose was electro-oxidized at a rate of 3 mA/cm^2 at 0.6 V vs Ag/AgCl in a quiescent solution.