A BIOFUEL CELL-BASED ON PYRROLOQUINOLINE QUINONE AND MICROPEROXIDASE-1 MONOLAYER-FUNCTIONALIZED ELECTRODES

A pyrroloquinoline quinone (PQQ) monolayer-functionalized-Au-electrode and a microperoxidase-11 (MP-11)-modified Au-electrode are used as ca talytic anode and cathode in a biofuel cell element, respectively. The cathodic oxidizer is H2O2 whereas the anodic fuel-substrate is 1,4-di hydronicotinamide adenine dinucleotide, NADH. The PQQ-monolayer electr ode catalyzes the oxidation of NADH in the presence of Ca2+ ions. The MP-11-functionalized electrode catalyzes the reduction of H2O2. The bi ofuel cell generates an open-circuit voltage, V-oc, of ca. 320 mV and a short-circuit current density, I-sc, of ca. 30 mu A.cm(-2). The maxi mum electrical power, W-max, extracted from the cell is 8 mu W at an e xternal load of 3 k Omega. The fill factor of the biofuel cell, f = W- max.I-sc(-1).V-oc(-1), is ca. 25%. (C) 1998 Elsevier Science S.A.