Kinetics of biocatalytic current generation

• Published in: Bioelectrochemistry and Bioenergetics 1983-01, Vol.10 (4), p.385-393
• Main Authors: Kulys, J.J., Samalius, A.S.
• Format: Article
• Language: English
• ISSN: 0302-4598
• DOI: 10.1016/0302-4598(83)80058-0

In the adsorption of peroxidase and cytochrome b 2 on charge-transfer electroconductive complexes the generation of the biocatalytic current of hydrogen peroxide reduction and l-lactate oxidation is first order. On the NMP + TCNQ − electrode the rate of the process for the corresponding enzymes is equal to 5.9 × 10 −3s −1 or 2.0 × 10 −3s −1 at 18 mV versus Ag|AgCl electrode and enzyme concentration 100n M. The current generation rate and limiting catalytic current ( I ∞ do not depend on the rotation rate of the disc electrode. The rate of current change depends on the concentration of enzymes or inert protein in the degree of 0.18–0.45. In the adsorption of cytochrome b 2 on the electrodes modified by polyethylenimine, the rate of the process and I ∞ are increased by 2.7 and 4.5 times respectively. In the case of peroxidase the modifiers do not influence the process rate, but considerably decreases the I ∞ value. The effect of potential, pH and modifiers is accounted for by the change in the surface state of electrodes and by the formation of electrocatalytically active complexes of enzymes with the electrode.