Photoelectrochemical enzymatic penicillin biosensor: A proof‐of‐concept experiment

Photoelectrochemical (PEC) biosensors are a rather novel type of biosensors that utilize light to provide information about the composition of an analyte, enabling light‐controlled multi‐analyte measurements. For enzymatic PEC biosensors, amperometric detection principles are already known in the literature. In contrast, there is only a little information on H + ‐ion sensitive PEC biosensors. In this work, we demonstrate the detection of H + ions emerged by H + ‐generating enzymes, exemplarily demonstrated with penicillinase as a model enzyme on a titanium dioxide photoanode. First, we describe the pH sensitivity of the sensor and study possible photoelectrocatalytic reactions with penicillin. Second, we show the enzymatic PEC detection of penicillin.