BIOELECTROCATALYSIS BY IMMOBILIZED PEROXIDASE - THE EFFECTS CAUSED BYTHE CARBON-BLACK SURFACE COVERAGE WITH THE ENZYME AND BY THE ENZYME-NAFION COMPOSITION ON THE ACTIVITY IN THE HYDROGEN-PEROXIDE REDUCTION

The coverage of the carbon black surface with adsorbed peroxidase is d etermined as a function of the enzyme concentration in solution. Speci fic activity in the hydrogen peroxide reduction is shown to he higher on the enzyme electrodes with the coverage below 0.15. A Nafion film a pplied on the carbon black surface with adsorbed peroxidase is found t o reduce biocatalytic activity of the electrode, increasing at the sam e time its stability. The dependences of the electrode activity and po larization capacitance on the applied amount of Nafion and the coverag e with adsorbed peroxidase are used to elucidate the structure of the composite bipolymer layer.