Bioelectrocatalysis by Immobilized Peroxidase: The Reaction Mechanism and the Possibility of Electroanalytical Detection of Both Inhibitors and Activators of Enzyme

Abstract

Electrocatalytic reduction of hydrogen peroxide by peroxidase immobilized throughits adsorption at carbon black was studied by using the rotating disk electrode technique. The reaction mechanism was proposed on the basis of experimental data concerning the influence of various parameters on the reaction rate: H₂O₂ concentration, the electrode rotation speed, solution pH, inhibitors and activators. The mechanism was found to be similar to that of peroxidase catalysis in the bulk of the solution, the electrode acting as aromatic reducer substrate. The results obtained on inhibition and activation of H₂O₂ electroreduction allows us to give recommendation on the electroanalytical detection of CN⁻, F⁻ ions and bensotriasol.

Key Words:

• direct bioelectrocatalysis
• peroxidase
• hydrogen peroxide
• rotating disk electrode
• inhibitors
• activators