Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, 610031, China.
Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu, 610031, China.
Mikrochim Acta. 2020 Aug 18;187(9):502. doi: 10.1007/s00604-020-04474-6.
A highly reproducible surface-enhanced Raman scattering (SERS) unsupported liquid-state platform (ULP) was developed for accurate quantitative determination of triazophos. Herein, citrate-reduced Ag NPs suspension was concentrated and placed in a stainless steel perforated template to form the SERS ULP. The relative standard deviation of the SERS measurements was less than 5% (n ≥ 10), and the R of the calibration curve was 0.994. The developed SERS ULP was applied for determination of triazophos in spiked agricultural products (rice, cabbage, and apple). Experiment results showed that the coefficient of variation ranged from 5.3 to 6.2% for intra-day and from 5.5 to 6.3% for inter-day (n = 3), which proved excellent SERS reproducibility. Moreover, the results were in good agreement with those from HPLC analysis. As a liquid-state SERS substrate, the highly reproducible ULP can perform precision quantitative analysis without surface modification of NPs, which is a significant improvement. This method provides a new perspective for quantitative SERS analysis of pesticide residues. Graphical abstract.
一种重现性好的无载体液相表面增强拉曼散射（SERS）平台（ULP）被开发出来，用于准确定量测定三唑磷。在此，通过浓缩柠檬酸钠还原得到的 Ag NPs 悬浮液，并将其置于不锈钢穿孔模板中，形成 SERS ULP。SERS 测量的相对标准偏差小于 5%（n≥10），校准曲线的 R 为 0.994。该 SERS ULP 用于测定加标农产品（大米、白菜和苹果）中的三唑磷。实验结果表明，日内变异系数为 5.3%至 6.2%，日间变异系数为 5.5%至 6.3%（n=3），证明了其具有出色的 SERS 重现性。此外，该结果与 HPLC 分析结果吻合较好。作为液相 SERS 基底，该重现性好的 ULP 无需对 NPs 进行表面修饰即可进行精密定量分析，这是一个显著的改进。该方法为农药残留的定量 SERS 分析提供了新视角。
