Laccase based synergistic electrocatalytical system

Abstract

Bioelectrodes employing the conversion of N-substituted phenothiazine/hexacyanoferrate(II) and N-substituted phenoxazine/hexacyanoferrate(II) that act as synergistic substrates were built using graphite electrode and recombinant laccase. The response of the bioelectrodes to low reactive substrate (hexacyanoferrate(II)) increases 2.9-97 times in presence of high reactive phenothiazine or phenoxazine mediator. The sensitivity of the bioelectrodes reaches 0.5-14.3 A/Mcm2. To background a scheme of bioelectrodes action the kinetics of laccase-catalyzed synergistic substrates oxidation was investigated in homogenous solution. A satisfactory agreement of experimentally determined rate constants and calculated using parameters of bioelectrocatalytical system confirms the scheme of bioelectrodes action.