Mathematical model of an amperometric biosensor for the design of an appropriate instrumentation system.

In this paper, a mathematical model for a membrane based amperometric biosensor is developed. The model is based on a diffusion mechanism related to Michaelis-Menten kinetics. The model is developed for an intensive stirred condition, so it has been assumed that the thickness of the diffusion layer is negligible. The model can be used to investigate the regularities and kinetics of the amperometric biosensor, and to develop any simulation methods to study the biosensor. The model shows that current I(t) generated during the specific biosensor enzymatic reaction mainly depends on the number of electrons generated and the area of working electrode. The model also describes the effect of background current in the biosensor. The validity of the developed model has been verified by designing a computer based instrumentation system for the amperometric biosensor. Repeated real time experiments were carried out, and the results obtained are in excellent agreement with the amount determined by high performance liquid chromatographic technique (HPLC), with an accuracy of +/-1.5%.