State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, PR China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, PR China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, PR China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi 214122, PR China.
State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, PR China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, PR China.
Spectrochim Acta A Mol Biomol Spectrosc. 2022 Feb 15;267(Pt 2):120542. doi: 10.1016/j.saa.2021.120542. Epub 2021 Oct 30.
Herein, we developed a PDMS-based flexible SERS substrate modified with gold nanostars (AuNSs) for in-situ detection of pesticide residues on fruit surfaces. AuNSs with sharp branches were assembled on aminated PDMS membrane by chemical bonding effect. The AuNSs/PDMS substrate showed good signal uniformity, stability and sensitivity using the Raman signal molecule 4-MBA and the detection concentration of 4-MBA was as low as 10 mol/L. Then the AuNSs/PDMS substrate was used to detect methyl parathion (MP) standard solution. A good linear relationship between SERS intensity at 1342 cm and MP concentration was established in the range of 4 μg/mL-100 μg/mL, and the limit of detection was down to 1.946 μg/mL. Moreover, the AuNSs/PDMS substrate was directly covered on the surface of MP contaminated apple, and the Raman laser was incident from the back of substrate to achieve in-situ detection of pesticide residues. The recovery ratio indicated that the fabricated SERS substrate was realized successfully in real sample detection. AuNSs/PDMS substrate eliminates the requirement for sample pre-processing steps before testing, which can be used as a method for rapid inspection of pesticide in agricultural products on site.
在此，我们开发了一种基于聚二甲基硅氧烷（PDMS）的柔性表面增强拉曼散射（SERS）基底，该基底修饰有金纳米星（AuNSs），用于原位检测水果表面的农药残留。通过化学键合作用，将具有锋利支叉的 AuNSs 组装到氨基化的 PDMS 膜上。AuNSs/PDMS 基底使用拉曼信号分子 4-巯基苯甲酸（4-MBA）表现出良好的信号均匀性、稳定性和灵敏度，其 4-MBA 的检测浓度低至 10 μmol/L。然后，我们使用 AuNSs/PDMS 基底检测甲基对硫磷（MP）标准溶液。在 4 μg/mL-100 μg/mL 的范围内，SERS 强度在 1342 cm 处与 MP 浓度之间建立了良好的线性关系，检测限低至 1.946 μg/mL。此外，我们直接将 AuNSs/PDMS 基底覆盖在 MP 污染的苹果表面上，拉曼激光从基底背面入射，实现了农药残留的原位检测。回收率表明，所制备的 SERS 基底成功实现了实际样品检测。AuNSs/PDMS 基底消除了在测试前对样品进行预处理的要求，可作为现场快速检测农产品中农药的一种方法。
