Rapid determination of thiram and atrazine pesticide residues in fruit and aqueous system based on surface-enhanced Raman scattering

In this work, a rapid and sensitive strategy was developed to determine thiram (THI) and atrazine (ATZ) by surface-enhanced Raman scattering (SERS) technology. β-cyclodextrin modified silver nanoparticles (β-CD-AgNPs) were synthesized using β-CD as a reducing agent and encapsulating agent under alkaline conditions and employed as SERS substrate. The existence of β-CD can capture the molecules to form host-guest complex and fix molecular orientation in its cavity, thus ensuring the enhanced SERS signal intensity of THI and ATZ. The linear response extends from 2.56 × 10-8 to 2.56 × 10-3 mol/L for THI and 3.08 × 10-8 to 3.08 × 10-3 mol/L for ATZ, with the limits of detection (LOD) of 2.42 × 10-9 mol/L for THI and 7.26 × 10-9 mol/L for ATZ, respectively. The application of the proposed method in real samples including apple and water were investigated, and the results would help promote the application of SERS technology as a powerful analytical tool for detecting other pesticide residues. It is expected that this SERS strategy will provide great value for rapid detecting pesticide residues in food products and environmental systems.