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

Abstract

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%.

Development of an Amperometric Biosensor and Performance Studies with a Minimum Background Current

“…The larger the area, the larger the current; at the same time, this larger area will require more electrolyte and more volume of electrolyte will lead to more background current [17] thereby affecting the sensitivity of the biosensor. Considering these limitations, we have optimized the areas.…”

“…[15,16] The current generated in an electrode based amperometric biosensor depends on both the sensing current and the background current. [15,17] In order to achieve better sensitivity of the enzyme electrode, the electrode has to exhibit very low background current. The major cause for the background current is the accumulated oxygen in the electrolyte of the biosensor itself.…”

Catalytic and Inhibitory Kinetic Behavior of Horseradish Peroxidase on the Electrode Surface

“…Andreu and coworkers [32] formulated analytical expressions describing the voltammetric response of a reagentless mediated enzyme electrode operated under rotating disk conditions. Patre and Sangam [33] built a model based on a diffusion mechanism related to Michaelis-Menten kinetics, which can be used in a membrane of the biosensor. Loghambal and Rajendran [34] worked out a steady-state non-linear reaction/diffusion equation.…”