Chloroferrocene-mediated laccase bioelectrocatalyst for the rapid reduction of O2

Abstract

Enzymatic biofuel cells are a promising and environmentally friendly technology for energy generation from renewable fuel sources. Glucose biofuel cells employ enzymatic catalysts at both the anode and cathode to oxidize glucose and reduce oxygen while producing electricity. Consequently, there is a need for materials capable of immobilizing enzymes and facilitating efficient electron transfer between an electrode surface and an enzymatic active site. Here, we describe a chloroferrocene-modified linear poly(ethylenimine) capable of mediating electro-enzymatic oxygen reduction by laccase. Enzymatic biocathodes constructed using this mediator generated current densities up to 2.66 mA cm−2, and up to 636 μW cm−2 (Eoc = 0.6 V) power when combined with a tetramethylferrocene-mediated glucose oxidase bioanode to construct a biofuel cell mediated entirely by ferrocenes.