Potentiometric enzyme biosensor for aflatoxin B1 detection – Kinetic simulation

Abstract

We have investigated the operation of a potentiometric biosensor based on reversible acetylcholinesterase inhibition for determination of aflatoxin B1. The biochemical reactions between enzyme, substrate, and inhibitor are described using rate equations. A sensitivity study of the biosensor response to the biochemical reaction rates was done by varying each rate constant. The response to substrate and inhibitor was used as a fitting target for evaluation of the biochemical reaction rates. Initial concentrations of the enzyme (2.0 × 10−5 M acetylcholinesterase), the substrate (4.0 × 10−3 M acetylcholine chloride), and the inhibitor (9.6 × 10−6 M aflatoxin B1) in the biosensor membrane act as the boundary conditions for the rate equations. This kinetic model allowed us to establish the effect of reaction rates on the biosensor response and reproduce the response to different inhibitor concentrations. The results may be used for biosensor design and optimization.