TY - JOUR A1 - Welden, Rene A1 - Jablonski, Melanie A1 - Wege, Christina A1 - Keusgen, Michael A1 - Wagner, Patrick Hermann A1 - Wagner, Torsten A1 - Schöning, Michael Josef T1 - Light-Addressable Actuator-Sensor Platform for Monitoring and Manipulation of pH Gradients in Microfluidics: A Case Study with the Enzyme Penicillinase JF - Biosensors N2 - The feasibility of light-addressed detection and manipulation of pH gradients inside an electrochemical microfluidic cell was studied. Local pH changes, induced by a light-addressable electrode (LAE), were detected using a light-addressable potentiometric sensor (LAPS) with different measurement modes representing an actuator-sensor system. Biosensor functionality was examined depending on locally induced pH gradients with the help of the model enzyme penicillinase, which had been immobilized in the microfluidic channel. The surface morphology of the LAE and enzyme-functionalized LAPS was studied by scanning electron microscopy. Furthermore, the penicillin sensitivity of the LAPS inside the microfluidic channel was determined with regard to the analyte’s pH influence on the enzymatic reaction rate. In a final experiment, the LAE-controlled pH inhibition of the enzyme activity was monitored by the LAPS. KW - microfluidics KW - enzyme kinetics KW - actuator-sensor system KW - light-addressable electrode KW - light-addressable potentiometric sensor Y1 - 2021 U6 - http://dx.doi.org/10.3390/bios11060171 SN - 2079-6374 N1 - This article belongs to the Special Issue "Selected Papers from the 1st International Electronic Conference on Biosensors (IECB 2020)" VL - 11 IS - 6 PB - MDPI CY - Basel ER -