Molecularly Imprinted Photoelectrochemical Sensor Based on AgBiS2/Bi2S3 for Determination of Propoxur

A molecularly imprinted photoelectrochemical sensor based on AgBiS 2 /Bi 2 S 3 was developed for detection of insecticide propoxur. AgBiS 2 /Bi 2 S 3 composites were synthesized on Ti substrate by solvothermal method. By using propoxur as a template molecule and o -phenylenediamine as a functional monomer, a molecularly imprinted polymer film was formed by electropolymerization on AgBiS 2 /Bi 2 S 3 composite material-modified Ti electrode for specific recognition of propoxur. The specific binding of propoxur with the imprinted cavity hindered the electron donor from passing through the cavity to the surface of the electrode, resulting in a decrease in photocurrent, and then propoxur was detected. The logarithm of the concentration of propoxur was linear with the photocurrent in the range of 1.0 × 10 −12 −5.0 × 10 −10 mol/L, and the detection limit was 2.3 × 10 −13 mol/L. The sensor was used for detection of propoxur residues in actual sample such as fruits, and the recoveries of the spiked standard were 101.0%–;103.1%.