Photoelectrochemical Clothianidin Detection Based on a WO ₃ /CdS Heterostructure Coated with a Molecularly Imprinted Thin Film

Clothianidin is an effective neonicotinoid insecticide and is harmful to human health. It is urgent to develop convenient analytical methods to determine clothianidin. In this study, a label-free photoelectrochemical (PEC) sensor for clothianidin was proposed. A type-II WO 3 /CdS heterojunction was prepared by chemical bath deposition method to enhance the photoelectric response. As a recognized element, the molecular imprinted polymer (MIP) film was formed on WO 3 /CdS by electropolymerization of o-phenylenediamine functional monomer in the presence of clothianidin template. Owing to the high photoelectric conversion efficiency of WO 3 /CdS heterostructure and the specific recognized ability of MIP, the as-prepared PEC sensor exhibits desirable analysis performance for clothianidin with high sensitivity and selectivity. This MIP-PEC sensor offers a wide linear detection range from 1.0 nM to 5.0 mM with a detection limit of 0.4 nM. The proposed sensor combines the merits of MIP and semiconductor heterojunction, presenting a promising prospect in the field of analysis.