A novel laccase-catalyzed cathode for microbial fuel cells

A microbial fuel cell (MFC) cathode was developed by immobilizing the enzyme, laccase, in polymer matrix (Nation) on carbon paper together with carbon nanoparticles and a redox mediator (2,2'-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt). The results from characterization of the immobilized laccase on the electrode indicate that the immobilization preserved laccase activity. Electro-chemical measurements demonstrate that the Nation film can facilitate electron exchange between the electroactive domain of laccase and the electrode. The electrocatalysis capabilities of the laccase-coated electrode were characterized by cyclic voltammogram (CV), which showed the electrode facilitated direct and surface-controlled redox reactions in a 0.1 M citrate buffer solution (pH 5.0). Additionally, when installed in a two-chamber MFC, the laccase-coated cathode demonstrates a strong catalytic potential that is comparable to a Pt-catalyzed cathode. (C) 2010 Elsevier B.V. All rights reserved.