Abstract: Imidacloprid (IMI), as a new type of neonicotinoid pesticide, poses potential health risks to humans when ingested long-term or in excessive amounts. Therefore, developing a rapid and highly sensitive detection technology for IMI residues is of great significance for ensuring food safety. In this study, we developed a indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) based on the peroxidase-like activity of platinum nanoparticles (PtNPs) for the quantitative detection of IMI residues in fruits and vegetables. The experimental results showed that the method exhibited good linearity in the concentration range of 0.1–100 μg/L (R2 = 0.995), with a detection limit of 0.115 μg/L. The recoveries for spiked yam, banana, and spinach ranged from 91.60% to 106.60%, demonstrating good accuracy and applicability. This method is simple to operate, and demonstrates high sensitivity and good specificity. Its overall performance meets the detection requirements of the current Chinese standards for the maximum residue limit of IMI in agricultural products.

Key words: platinum nanoparticles; mimic enzyme; peroxidase-like; colorimetric method; imidacloprid; indirect competitive enzyme-linked immunosorbent assay; fruits and vegetables