Amperometric enzyme electrodes: Part I. Theory

The theory of the steady state operation of an amperometric enzyme is derived. The reaction scheme includes diffusion of substrate and product through a membrane, the kinetics of the enzyme substrate reaction and the electrochemical regeneration of the enzyme. A simple diagnostic plot is derived which allows the rate limiting process to be identified, and the balance between the transport of substrate through the membrane and the enzyme and electrochemical kinetics to be determined. The effects of inhibition by the accumulation of product behind the membrane are also considered.