Boosted photoelectrochemical sensor for methyl parathion detection in vegetables based on covalent organic frameworks@BiWO quantum dots nanocomposites grafted electron donor-acceptor molecularly imprinted polymers.

An ultrasensitive and selective photoelectrochemical (PEC) sensor for methyl parathion (MP) determination was exploited by using BiWO quantum dots (QDs)/Wurster-type covalent organic frameworks (COFs) heterostructure grafted electron donor-acceptor molecularly imprinted polymers (MIPs). BiWO QDs/COF composites were used as the photoelectrically active material and MIPs were electrochemically deposited on them with MP and p-aminothiophenol acting as the electron acceptor and donor, respectively. Owing to the boosted charge transfer efficiency and enhanced photoelectric currents by the BiWO QDs/COF composites, as well as the high specificity provided by the combination of the donor-acceptor mechanism and molecular imprinted technology, the designed sensor achieved a linear range from 10.0 fmol L to 1.0 nmol Land an extremely low detection limit of 1.096 fmol L. Moreover, it showed good reliability and practicability in real samples assay. This study expanded the application of PEC sensors in food safety risk monitoring.