A molecularly imprinted photoelectrochemical sensor based on an rGO/MoSSe heterojunction for the detection of chlortetracycline

A reduced graphene oxide/molybdenum selenosulfide (rGO/MoSSe) heterojunction was synthesized, and a molecularly imprinted photoelectrochemical sensor for the detection of chlortetracycline was prepared. MoSSe was grown in situ on rGO by a hydrothermal method to form an rGO/MoSSe heterojunction, which acts as the sensitive film of the sensor. Since rGO can promote electron transfer and effectively inhibit electron–hole recombination, it effectively reduces the recombination probability of electrons and holes and improves the photoelectric efficiency, thus enhancing the detection sensitivity of the PEC sensor. The rGO/MoSSe was immobilized on an FTO electrode, and molecularly imprinted polymers (MIPs) were prepared by electropolymerization on the rGO/MoSSe-modified FTO electrode with chlortetracycline as the template molecule and o-phenylenediamine as the functional monomer, so as to construct a molecularly imprinted photoelectrochemical (MIP-PEC) sensor. The determination of chlortetracycline was realized by the strategy of a “gate-controlled effect”, and the detection range of the chlortetracycline concentration was 5.0 × 10−13–5 × 10−9 mol L−1 with a detection limit of 1.57 × 10−13 mol L−1. The sensor has been applied to the determination of chlortetracycline in animal-derived food samples.