Abstract:The application of QuEChERS in SERS detection of pesticide residues in agricultural products can effectively improve the detection accuracy. In this paper, based on the QuEChERS optimization results for SERS detection of acetamiprid in citrus, it was applied to the SERS analysis of other pesticide residues in citrus to explore the universality of this method for SERS detection of pesticide residues in citrus.The influence of Nano-bamboo charcoal (NBC) and Ferric oxide nanoparticles (Fe3O4MNPs) purification agent on the SERS of acetamiprid in citrus was studied. The results showed that 12.5mg NBC and 10mg Fe3O4 had the best purification effect. In the range of 0.1 ~ 40 mg/L, based on the characteristic peak intensity of 626 cm-1, the SERS analysis equation y = 65.011x + 103.25 (R2 = 0.9953) was established with an average recovery of 97% ~ 106%. The relative standard deviation (RSD) was 1.03% to 4.04%, and the lowest detection concentration was about 0.1 mg/L.The method was applied for the SERS analysis of organophosphorus insecticides (chlorpyrifos and profenofos), neonicotinoid insecticides (imidacloprid and acetamiprid) and insect growth regulator insecticides (buprofezin) in citrus, and the average recovery rate was between 87.60% and 106%, and the relative standard deviation (RSD) ranged from 1.03% to 7.71%, indicating that QuEChERS could be used for the rapid detection and analysis of SERS of different pesticide residues in citrus. The detection time of a single sample in this method was completed within 20 min, which laid a foundation for the development of rapid detection methods for pesticide residues in citrus.