Validation of a time-variant electrical equivalent circuit for a dry bacteriorhodopsin sensor

The photoelectric response of dry bacteriorhodopsin sensors varies depending on whether the incident light is on or off. To model this behavior, we have proposed an electrical equivalent circuit that has a capacitor that varies with the light intensity. In this paper, the proposed model is experimentally validated and found to be appropriate even when the light intensity is changed. The results also confirm that the amplitude of the measured photocurrent changes linearly with the light intensity. The results can be used to correctly analyze and model photocurrent measurements taking the time-variant behavior of the photosensitive biological sensor into account. This knowledge will be useful in sensing systems that utilize photosensitive biological sensors.