Light-addressable chemical sensors: Modelling and computer simulations

Abstract A light-addressable potentiometric sensor (LAPS) has recently been proposed as a pH sensor. A LAPS description is presented that is suitable for direct applications as a built-in model in circuit-simulation programs, such as SPICE. The model equations describing the LAPS behaviour have been formulated by modelling the electrolyte-insulator interface via site-binding theory, and by modelling, via semiconductor theory, the insulator-semiconductor structure under the photogeneration effects induced by an externally addressed light. Simulation results are presented, focused on the analysis of the detection of transient acidification phenomena.