Sensitive and selective fluorescence detection of acetamiprid using oxidized single-walled carbon nanohorns and cryonase-assisted signal amplification

To address the low accuracy of pesticide residue detection in traditional Chinese medicine, we developed a biosensor for acetamiprid detection. First, an oxidized single-walled carbon nanohorn capable of adsorbing and quenching fluorescence was prepared. Second, a novel fluorescence sensing system was constructed based on this nanomaterial. The detection performance of the sensor system was evaluated, which revealed that fluorescence quenching by the biosensor was primarily due to the adsorption of the aptamer by the nanomaterials. Optimal conditions were found to be a nanomaterial mass concentration of 800 ng/mL and an incubation time of 70 min, which resulted in the best fluorescence response. Under these optimal conditions, the system was used to detect acetamiprid residues in traditional Chinese medicine. The fluorescence intensity showed a strong linear relationship with acetamiprid concentration, with a correlation coefficient of 0.9985 and a detection limit of 6.33 ng/mL. In the sample test, the biosensor demonstrated high accuracy, with good average recovery rates and low relative standard deviation. The system showed excellent selectivity and detection performance, with no interference from other pesticides.