DIGITAL-SIMULATION OF HOMOGENEOUS ENZYME-KINETICS FOR AMPEROMETRIC REDOX-ENZYME ELECTRODES

An explicit point method is described for digital simulation of redox-enzyme catalysis and diffusion at soluble-enzyme electrodes. Two experimental conditions (chronopotentiometry and open-circuit potential decay) were simulated for a two-substrate enzyme (glucose oxidase) catalyzing the anaerobic oxidation of glucose, mediated by a soluble redox couple. Transient and steady-state responses are compared to experimental data and to predictions of the analytical solutions for selected cases. Simulated steady-state concentration profiles near the electrode surface are analyzed for different values of K(S)/C(S) and K(O)/C(O). The validity of linear Lineweaver-Burk plots for the amperometric response of enzyme electrodes is discussed.