Functional modeling of electrochemical whole-cell biosensors

The response modeling of whole-cell biochip represents the link between cellular biology and transducer output, allowing better system engineering. It provides the mathematical background for signal and noise modeling, performance prediction and data analysis. Here we describe an analytical model for whole-cell biosensors with electrochemical detection for single use, test and dispose applications. In this system the electrochemical signal is generated by the oxidation of the by-products of the reaction between an external substrate and the enzyme alkaline phosphatase. The enzyme expression can be either normal or enhanced due to the response of the biological cell to an external excitation. The electrochemical oxidation current is measured as a function of time. The model is based on the electrochemical reaction rate equations; an analytical solution is presented, compared to data and discussed.