Engineered Plasmonic multi-hot spots on magnetic Nanospheres for quantitative detection of pesticide residues on food surfaces via SERS tagging analysis

Pesticide application ensures the yield of crops and reduces the harm of pathogenic microorganisms to the human body. However, excessive use of pesticides leads to their residues on the surface of foods, thus posing a threat to human health and the ecological environment. Herein, Fe₃O₄@Au@1,4-BDT@Au nanoparticle, as a novel three-dimensional surface-enhanced Raman scattering (SERS) substrate, was constructed enabling the rapid and quantitative detection of pesticide residues of food surfaces combined with a portable Raman spectrometer, which integrates the advantages of multiple components, such as magnetic effect enrichment, Raman internal standard, and strong electromagnetic fields via coupling of gold nanoparticles. In practical detection, the limit of quantitation (LOQ) of thiram and malachite green are 2.5 × 10 −7  M and 10 −10  M, respectively. Furthermore, the proportion of mixed pesticides is determined by principal component analysis (PCA), which provides an effective solution for the simultaneous detection of multiple pesticide residues in complex detection conditions.