Laccase Based Synergistic Electrocatalytical System

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/M⋅cm2. 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.