Fluorescence homogenous analysis based on AgNPs quenching carbon dots and polymer dots for simultaneous detection of glyphosate and thiamethoxam in food

A novel homogeneous fluorescence analysis method was developed for the simultaneous detection of glyphosate (GLY) and thiamethoxam (TMX) using aptamer-functionalized carbon dots and polymer dots in conjunction with complementary chain-modified silver nanoparticles (AgNPs). This analytical strategy is based on the principles of fluorescence resonance energy transfer and an indirect competition reaction model. The fluorescence intensity shows a linear correlation with the logarithm of GLY and TMX concentrations over the range of 0.5–1000 ng/mL. The limits of detection for GLY and TMX were determined to be 0.12 ng/mL and 0.10 ng/mL, respectively. The method was successfully applied to the detection of GLY and TMX in various matrices (tap water, apple, pear, and rapeseed oil), with the results being verified by HPLC. This study presents a cost-effective, rapid, and highly sensitive detection method, which holds great promise for future applications in environmental and food-related fields.