A kinetic approach to oxidase based enzyme electrodes: the effect of enzyme layer formation on the response time

The formation of the enzyme layer of the sandwich type electrodes has been altered and evaluated in terms of kinetic performance. The detection of H2O 2 serves to measure the extent of the reaction. The kinetics of the recogni tion layer are discussed in terms of the response rime of the electrode. Th e enzyme loading between two membranes has altered mass transfer limitation s resulting in significant changes in the response of the electrode. The ef fectiveness factor is used to describe the mass transfer limitations in the system. The response time of the electrode has been increased while the ef fectiveness factor has been decreased. Steady-state response of the electro des has been achieved in 43, 68 and 98 s for the electrodes including 23.1% , 13.0% and 7.0% (w/w) GOD in a BSA + GOD mixture, respectively. The effect iveness factors for these electrodes have been established at the values of 0.59, 0.38 and 0.16, respectively. (C) 1998 Elsevier Science S.A.