School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China.
China Light Industry Key Laboratory of Food Intelligent Detection & Processing, Jiangsu University, Zhenjiang 212013, China.
Molecules. 2023 Jul 8;28(14):5291. doi: 10.3390/molecules28145291.
Dicofol is a highly toxic residual pesticide in tea, which seriously endangers human health. A method for detecting dicofol in tea by combining stoichiometry with surface-enhanced Raman spectroscopy (SERS) technology was proposed in this study. AuNPs were prepared, and silver shells were grown on the surface of AuNPs to obtain core-shell Au@AgNPs. Then, the core-shell Au@AgNPs were attached to the surface of a PDMS membrane by physical deposition to obtain a Au@AgNPs/PDMS substrate. The limit of detection (LOD) of this substrate for 4-ATP is as low as 0.28 × 10 mol/L, and the LOD of dicofol in tea is 0.32 ng/kg, showing high sensitivity. By comparing the modeling effects of preprocessing and variable selection algorithms, it is concluded that the modeling effect of Savitzky-Golay combined with competitive adaptive reweighted sampling-partial least squares regression is the best (Rp = 0.9964, RPD = 10.6145). SERS technology combined with stoichiometry is expected to rapidly detect dicofol in tea without labels.
三氯杀螨醇是茶叶中一种高毒残留农药，严重危害人类健康。本研究提出了一种将化学计量学与表面增强拉曼光谱（SERS）技术相结合检测茶叶中三氯杀螨醇的方法。制备了 AuNPs，并在 AuNPs 表面生长银壳，得到核壳 Au@AgNPs。然后，通过物理沉积将核壳 Au@AgNPs 附着在 PDMS 膜的表面上，得到 Au@AgNPs/PDMS 基底。该基底对 4-ATP 的检测限（LOD）低至 0.28×10 mol/L，茶叶中三氯杀螨醇的检测限为 0.32ng/kg，表现出高灵敏度。通过比较预处理和变量选择算法的建模效果，得出 Savitzky-Golay 结合竞争自适应重加权采样-偏最小二乘回归的建模效果最好（Rp=0.9964，RPD=10.6145）。预计 SERS 技术与化学计量学相结合将无需标记即可快速检测茶叶中的三氯杀螨醇。
