基于银薄膜/荷叶SERS效应直接检测婴儿配方奶粉中三聚氰胺

以天然荷叶为衬底,结合真空磁控溅射法沉积银薄膜,制备出了一种高效的表面增强拉曼散射(SERS)活性基底.研究发现银/荷叶基底对婴儿配方奶粉中掺杂的三聚氰胺(MA)表现出良好的识别能力,而不需作额外的样品预处理.对掺杂不同浓度三聚氰胺的奶粉溶液进行定量分析,在5~50 mg/L质量浓度范围内获得了较好的线性关系(线性相关系数R20.99).根据3σ准则,检测极限估计为1 mg/L.此外,银/荷叶基底具有良好的均匀性和重复性(相对标准偏差为7.64%和10.54%).该方法对婴儿配方奶粉中三聚氰胺的检测具有简单快速、成本低且无损等优点.

Direct detection of melamine in infant formula milk powder based on SERS effect of silver thin film coated lotus-leaf

An efficient surface-enhanced Raman scattering (SERS) substrate has been developed by depositing silver thin film on natural lotus leaf (Ag/lotus-leaf) with vacuum magnetron sputtering method.It was found that the Ag/lotus-leaf substrate showed excellent ability to recognize melamine molecules in infant formula milk powder directly without any sample pretreatment.Quantitative analyses of melamine in milk powder solution at different concentrations were carried out.A good linear relationship was obtained at concentrations ranging from 5 mg/L to 50 mg/L,and the correlation coefficient (R²) of the curve was larger than 0.99.According to the rule of 3σ,the limit of detection is estimated to be 1 mg/L.Furthermore,the Ag/lotus-leaf substrate exhibited good uniformity and reproducibility with relative standard deviation (RSD) values of 7.64% and 10.54%.This method was simple,fast,nondestructive,and inexpensive for the detection of melamine in infant formula milk powder.