Mathematical modeling of a tethered bilayer sensor containing gramicidin a ion channels

This paper considers the mathematical modeling of chemical kinetics and electrical dynamics of a tethered bilayer biosensor, comprising of Gramicidin A (gA) ion channels. The electrical dynamics of the biosensor are modeled by an equivalent second order linear system. The chemical kinetics of the biosensor, which involve the binding of analyte to the receptor sites immobilized on the biosensor surface, are modeled in both the reaction-rate-limited regime, where analyte concentration is constant through out the biosensor flow chamber, and the mass transport influenced region, where the analyte concentration is subject to variations in time and space. Using the theory of singular perturbation, we show that the channel conductance varies according to one of three possible modes depending on the analyte concentration present.