Conductive hydrogel for bio-electrocatalytic reduction of dioxygen

An enzyme-immobilized electrode represents an important kind of biosensor or bioelectronic device. In this paper, a method of incorporating laccase on an electrode was demonstrated using the electrosynthesis of polypyrrole (pPy) with its redox mediator and alginate as co-dopants. Linear sweep voltammetry showed that the pPy film exhibited biocatalytic activity towards oxygen to water reduction. The catalytic activity and the stability of the film could be controlled by the concentration of alginate used during electrosynthesis. A micropattern of the film revealed its bi-layer structure - where an inner layer of pPy was covered with an outer layer of alginate gel, and demonstrated the geometric control of the film deposition.