The novel aspects of the proposed work are (1) the use of a plasmon enhanced photocatalytic reaction in (photo)electrochemical analysis; (2) the use of electrochemical methods for the characterization of photocatalysis on hybrid materials (plasmonic nanoparticles modified by photosensitizers); (3) the introduction of an affinity recognition element in photocatalytic electrochemical analysis; (4) the development a photoelectrochemical sensing platform with intrinsic background correction (laser on/off) for on-site monitoring of surface water.
In this work we explore further our original idea published in Nature Communications (Trashin et al. 2017), based on the electrochemical detection of the phenolic moiety in amoxicillin due to its photocatalytic oxidation by a photosensitizer followed by reduction reaction at an electrode (Figure 1). This approach is more sensitive comparing to direct electrochemical oxidation of phenols, it does not require a harsh overpotential, and shows the baseline at any point of the measurement by switching off the laser. However, this method needs one order of magnitude improvement in limit of detection to meet required specification for surface water analysis. According to our knowledge, no sensing methodology was introduced to measure pharmaceuticals at this concentration level in surface or sewage water.