Fluorescence Quenching Detection of Clothianidin in Fruit and Vegetable Samples Using MAPbBr₃ Perovskite Quantum Dots

Highly stable and photoluminescent methylammonium lead halide perovskite quantum dots (MAPbBr 3 PQDs) have been synthesized and applied for the fluorescence quenching detection of clothianidin in fruit and vegetable samples. Characterizations using different techniques, including photoluminescence (PL), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and time-resolved PL (TRPL), show that static quenching is the dominant fluorescence quenching mechanism of MAPbBr 3 PQDs with clothianidin. Hydrogen bonds or van der Waals forces play major roles in the MAPbBr 3 PQDs–clothianidin interaction. Under optimized conditions, the relative PL intensity of MAPbBr 3 PQDs is linear to the concentration of clothianidin in the 0.0 and 20.0 mg/L range with a detection limit of 0.17 μg/kg. Excellent recoveries of 79.5–115.4% were acquired for radish and banana samples with a relative standard deviation below 9.4%. These results indicate that PQDs can be used for qualitative and quantitative identification of clothianidin, providing an effective detection method for risk prevention and control of neonicotinoid pesticide residues in agricultural products.