The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, PR China.
Talanta. 2012 May 15;93:398-403. doi: 10.1016/j.talanta.2012.02.062. Epub 2012 Mar 3.
A sensitive and simple method for the determination of melamine (MA) was developed based on the fluorescence enhancement effect of MA for thioglycolic acid-capped (TGA-capped) CdS quantum dots (QDs). Under optimum conditions, a good linear relationship was obtained from 2.0 × 10(-9) to 5.0 × 10(-5)M. The detection limit was 1.0 × 10(-9)M, which was much lower than the safety limit (2.5 ppm in USA and the UK; 1 ppm for infant formula in China). The solution pH, the adding sequence of the buffer solution and MA and surface modifiers of CdS QDs greatly influenced the enhancement extent of MA for CdS QDs. The fluorescence enhancement was attributed to the surface passivation of the surface states of QDs by amine group of MA. The method was applied to detect MA in raw milk with satisfactory results. The proposed method manifested several advantages such as high sensitivity, short analysis time, low cost and ease of operation.
基于三聚氰胺（MA）对巯基乙酸（TGA）修饰的硫化镉量子点（CdS QDs）荧光增强效应，建立了一种灵敏且简单的 MA 测定方法。在最佳条件下，从 2.0×10(-9)到 5.0×10(-5)M 得到了良好的线性关系。检测限低至 1.0×10(-9)M，远低于美国和英国的安全限量（2.5ppm）和中国婴幼儿配方奶粉中的限量（1ppm）。溶液 pH 值、缓冲溶液和 MA 的加入顺序以及 CdS QDs 的表面修饰剂极大地影响了 MA 对 CdS QDs 的增强程度。荧光增强归因于 MA 的氨基基团对 QDs 表面态的表面钝化。该方法已成功应用于生牛乳中 MA 的检测，结果令人满意。该方法具有灵敏度高、分析时间短、成本低、操作简便等优点。
