Enzymatic Biofuel Cell for Oxidation of Glucose to CO2

Glucose has been widely studied as a fuel in biofuel cells because it not only is abundant in nature and in the bloodstream but also demonstrates low volatility, is nontoxic, and is inexpensive. Those qualities coupled with its relatively high energy density qualify glucose as a promising fuel. However, one key to efficient use of this substrate as fuel is the ability to oxidize glucose to CO2 and convert, more efficiently, the chemical energy released upon the redox reactions to electrical power. Most ! glucose biofuel cells in literature only oxidize glucose to gluconolactone. In this paper, we report the development of a six-enzyme cascade bioanode containing pyrroloquinoline quinone-dependent enzymes extracted from Gluconobacter sp., aldolase from Sulfolobus solfataricus and oxalate oxidase from barley to sequentially oxidize glucose to carbon dioxide through a synthetic minimal metabolic pathway. This bioanode is also capable of performing direct electron transfer to carbon electrode surfaces and eliminates the need for mediators.