College of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, China.
Shenzhen Institute of Guangdong Ocean University, Shenzhen 518108, China.
Sensors (Basel). 2019 Mar 19;19(6):1363. doi: 10.3390/s19061363.
A method is developed for detecting the concentration of sodium thiocyanate (NaSCN) in milk based on surface-enhanced Raman scattering (SERS) technology. A trichloroacetic acid solution can be used to enhance the SERS signal because of its function in promoting the aggregation of Ag nanoparticles (Ag NPs). Meanwhile, the protein in milk would be precipitated as trichloroacetic acid added and the interference from protein could be reduced during the detection. In this work, the enhancement factor (EF) is 7. 56 × 10⁵ for sodium thiocyanate in water and the limit of detection (LOD) is 0.002 mg/L. Meanwhile, this method can be used to detect the concentration of sodium thiocyanate in milk. Results show that SERS intensity increased as the concentration of sodium thiocyanate increase from 10 to 100 mg/L. The linear correlation coefficient is R² = 0.998 and the detection limit is 0.04 mg/L. It is observed that the concentration of sodium thiocyanate does not exceed the standard in the three kinds of milk. The confirmed credibility of SERS detection is compared with conventional methods.
建立了一种基于表面增强拉曼散射（SERS）技术检测牛奶中亚硝酸钠（NaSCN）浓度的方法。三氯乙酸（TCA）溶液可用于增强 SERS 信号，因为它具有促进银纳米粒子（Ag NPs）聚集的作用。同时，加入三氯乙酸会使牛奶中的蛋白质沉淀，从而减少检测过程中蛋白质的干扰。在这项工作中，水相中亚硝酸钠的增强因子（EF）为 7.56×10⁵，检测限（LOD）为 0.002mg/L。同时，该方法可用于检测牛奶中亚硝酸钠的浓度。结果表明，随着亚硝酸钠浓度从 10mg/L 增加到 100mg/L，SERS 强度增加。线性相关系数为 R²=0.998，检测限为 0.04mg/L。观察到三种牛奶中的亚硝酸钠浓度均未超过标准。SERS 检测的可靠性与常规方法进行了比较。
