Oxygen vacancies-driven self-powered photoelectrochemical sensor for acetamiprid detection.

Residues of acetamiprid (ACT) in agricultural products may enter the human body with the diet and subsequently cause potential harm to humans. Therefore, it is necessary to establish a rapid and sensitive method to detect ACT. In this work, a self-powered ACT photoelectrochemical (PEC) sensor using W18O49/CdS as photoanode, BiOCl as photocathode, and Au@PANI as the signal amplification marker was constructed. The matched band gap structure of the W18O49/CdS can effectively accelerate the charge transfer, laying the foundation for a strong and stable photocurrent response at the cathode. In particular, the introduction of oxygen vacancies can induce defects on the surface of the photosensitive material, facilitating the separation of photogenerated carriers. When the target analyte ACT was introduced, the signal amplification was achieved by using ACT to compete with c-DNA for specific binding sites and inducing p-DNA-Au@PANI shedding. With the synergistic effect of the above multiple strategies, the designed sensor exhibits good linearity in the range of 100 fM ∼1 μM with a detection limit of 65.8 fM (S/N = 3). In addition, the sensor has excellent selectivity, stability, reproducibility, and also shows good analytical performance in real sample. It provides a reliable method for detection of ACT.