Stable “Floating” Air Diffusion Biocathode Based On Direct Electron Transfer Reactions between Carbon Particles and High Redox Potential Laccase

Sergey Shleev (1) , Galina Shumakovich (2) , Olga Morozova (2) , Alexander Yaropolov (2)

1 Biomedical Lab Science
2 Chemical Enzymology

We report on the assembly and characterisation of a high potential, stable, mediator-less and cofactor free biocathode based on a fungal laccase adsorbed on highly dispersed carbonaceous materials. First, the stability and activity of Trametes hirsuta laccase immobilised on different carbon particles were studied and compared to the solubilised enzyme. Based on the experimental results and a literature analysis, the carbonaceous material BM-4 was chosen to design efficient and stable biocatalysts for the production of a “floating” air diffusion laccase-based biocathode. The current density of oxygen reduction at the motionless biocathode in a quiet, air saturated citrate buffer(100 mM, pH 4.5, 23°C) reached values as high as 0.3 mA cm^-2 already at 0.7 V vs. NHE. At low current density (20 µA cm^-2), the biocathode lost only 5 percent of its initial power after one month of continuous operation. However, when the device was polarised at 150 mV it lost more than 32 percent of its initial power in just 10 min. We found that co-immobilisation of laccase and peroxidase on highly dispersed carbon materials could preserve the biocatalyst from rapid inactivation by hydrogen peroxide produced during electrocatalytic reactions at high current densities.

Mots clés: Physical Sciences

Sergey Shleev, Galina Shumakovich, Olga Morozova, Alexander Yaropolov. Stable “Floating” Air Diffusion Biocathode Based On Direct Electron Transfer Reactions between Carbon Particles and High Redox Potential Laccase. Fuel Cells, 2010, 10 (4), pp.726. ⟨10.1002/fuce.200900191⟩. ⟨hal-00552369⟩