Constant-Current-Mode LAPS (CLAPS) for the Detectionof Penicillin

Abstract

A software feedback control system for the constant-current-mode operation of the light-addressable potentiometric sensor (LAPS) was developed. The constant-current-mode LAPS (CLAPS) is suitable for online monitoring and recording of changes in the pH value or the ion concentration. An enzyme LAPS was fabricated by adsorptive immobilization of penicillinase on the pH-sensitive layer of Ta2O5. This sensor was operated in the constant-current-mode and the detection limit for penicillin G was found to be at least as low as 100 µM.