Gold‐Decorated Carbon Composite Electrodes for Enzymatic Oxygen Reduction

Abstract

AbstractFunctional composites of carbon and gold nanoparticles create a hierarchical architecture that facilitates high enzyme loading. Subsequent immobilization of the multicopper oxidase, Trametes versciolor laccase, was optimal with dithiobis‐ (succinimidyl propionate), due to the formation of thiol bonds between the protein molecules and gold. The immobilized laccase catalyzed oxygen reduction, with an onset potential of ∼0.6 V (vs. Ag/AgCl), indicated effective orientation of the enzyme redox center to enable direct electron transport between enzyme and the composite electrode. Current densities in half‐cell configurations provide scalable outputs of 50–80 µA/cm2 with the optimized electrode design. The methodology herein describes a rapid, facile preparation of gold‐decorated carbon composite materials for use as electrode scaffolds that can be integrated into a range of bioelectronic devices.