Electron transfer (ET) of versatile peroxidase (VP) was studied in the bioelectrocatalytic reduction reaction of H2O2 at peroxidase-modified graphite electrodes to obtain additional information on the kinetic characteristics of this novel ligninolytic peroxidase. Rotating disk electrodes (RDE)experiments were performed at 0 V (vs. SCE) in two different buffers(tartrate buffer, pH 5.0; and citrate buffer, pH 3.0). From measurements of the mediated

The ability of Trametes villosa laccase to degrade an azo dye (methyl orange) and to catalyze the coupling reactions between the aromatic amines and catechol was studied. It was found that the apparent Michaelis-Menten constants obtained from amperometric measurements were comparable to the ones obtained in the oxygen consumption experiments (8.20 and 7.40
M, respectively). From the measurements of the mediated and mediatorless currents of azo dye

A simple and inexpensive amperometric biosensor for formate detection was obtained by immobilization of formate dehydrogenase (FDH) on graphite powder, modified with a new phenothiazine derivative (DDDP; 16H, 18H-dibenzo[c,1]-7,9-dithia-16,18-diazapentacene). Two different enzyme environments were used: FDH was adsorbed on DDDP-modified graphite powder in the presence of polyethylenimine (PEI) as well as in its absence. In both cases, when 10 mM