title: Magnetic field effects on bioelectrocatalytic reactions of surface-confined enzyme systems: enhanced performance of biofuel cells.
abstract: The effect of a constant magnetic field on bioelectrocatalytic transformations of three different enzyme assemblies linked to electrodes is examined and correlated with a theoretical magnetohydrodynamic model. The systems consist of surface-reconstituted glucose oxidase (GOx), an integrated lactate dehydrogenase/nicotinamide/pyrroloquinoline quinone assembly (LDH/NAD+ -PQQ), and a cytochrome c/cytochrome oxidase system (Cyt c/COx) linked to the electrodes. Pronounced effects of a constant magnetic field applied parallel to the electrode surface are observed for the bioelectrocatalyzed oxidation of glucose and lactate by the GOx-electrode and LDH/NAD+ -PQQ-electrode, respectively. The enhancement of the bioelectrocatalytic processes correlates nicely with the magnetohydrodynamic model, and the limiting current densities (iL) relate to B1/3 (B = magnetic flux density) and to C4/3 (C* = bulk concentration of the substrate). A small magnetic field effect is observed for the Cyt c/COx-electrode, and its origin is still questionable. The effect of the constant magnetic field on the performance of biofuel cells with different configurations is examined. For the biofuel cell consisting of LDH/NAD+ -PQQ anode and Cyt c/COx cathode, a 3-fold increase in the power output was observed at an applied magnetic field of B = 0.92 T and external load of 1.2 kOhms.
authors.affiliation: Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Eugenii
authors.initials: E
authors.lastname: Katz
authors.forename: Oleg
authors.initials: O
authors.lastname: Lioubashevski
authors.forename: Itamar
authors.initials: I
authors.lastname: Willner
mesh_terms: D001674:Bioelectric Energy Sources; D015374:Biosensing Techniques / Q000379:methods; D002384:Catalysis; D045304:Cytochromes c / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods; D003576:Electron Transport Complex IV / Q000737:chemistry*; D004800:Enzymes, Immobilized / Q000737:chemistry*; D005949:Glucose Oxidase / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D007770:L-Lactate Dehydrogenase / Q000737:chemistry*; D008280:Magnetics; D009536:Niacinamide / Q000737:chemistry; D010084:Oxidation-Reduction; D045542:PQQ Cofactor / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D009536:Niacinamide; D045542:PQQ Cofactor; D006046:Gold; D045304:Cytochromes c; D007770:L-Lactate Dehydrogenase; D005949:Glucose Oxidase; D003576:Electron Transport Complex IV