Chlorpyrifos detection in strawberry and soil samples using a direct Z-scheme heterojunction photoelectrochemical sensor based on Bi2WO6 nanosheets loaded with MOFs-derived In2O3 hollow nanotubes

Chlorpyrifos (CPF) is widely utilized in agricultural practices, and its residue in food raise significant concerns food safety. However, current detection methods often suffer from complex operation procedures and unstable signal responses. Therefore, there is an urgent need to develop a reliable sensor for detecting CPF residue in food samples. In this work, a Z-scheme heterojunction was formed using hollow In 2 O 3 (H-In 2 O 3 ) and Bi 2 WO 6 nanosheets. The staggered band structure of the H-In 2 O 3 /Bi 2 WO 6 heterojunction facilitates carrier separation and transfer, thereby enhancing the sensor's response. In the presence of CPF, it reacts with · OH radicals generated by the heterojunction, further amplifying the signal. The sensor exhibits a linear response in the range of 5–700 nM with a limit of detection (LOD) of 0.72 nM. In addition, this photoelectrochemical sensor demonstrates satisfactory stability, anti-interference, selectivity and reproducibility, showing great potential for CPF analysis in real samples.