高灵敏CdTe量子点探针的构建及与金属离子的作用

采用变性的牛血清白蛋白(dBSA)对水相合成的CdTe量子点进行修饰, 构建了高灵敏金属离子探针, 研究了其对重金属离子的检测性能并对机理进行了探讨. 通过优化反应条件, 合成了具有高量子产率的以巯基乙酸为稳定剂的水溶性CdTe量子点, 并采用变性的牛血清白蛋白分别对不同粒径的CdTe量子点进行修饰, 确定变性的牛血清白蛋白与不同粒径量子点之间的最佳比例. 在纯化变性的牛血清白蛋白修饰的量子点(dBSA-QDs)的基础上, 研究了该量子点与不同金属离子的作用. 结果表明, 量子点经修饰后, 其量子产率、 抗光漂白性及稳定性得到显著提高; 而且dBSA-QDs的荧光可被重金属离子有效猝灭, 与巯基乙酸稳定的量子点(TGA-QDs)相比, 检测灵敏度显著提高.

Construction of High-Sensitivity CdTe Quantum Dots as Fluorescence Probe and Its Interaction with Metal Ions

We used denatured bovine serum albumin(dBSA) to modify water-soluble CdTe quantum dots(QDs),constructed the metal ion probe with high detection sensitivity,and studied its detection performance and mechanism for heavy metal ions.Water-soluble CdTe quantum dots with a high quantum yield and thioglycolic acid(TGA) as stabilizer were synthesized by optimizing the reaction conditions.We used dBSA to modify the CdTe QDs of different sizes respectively,determined the optimum ratios of dBSA to QDs.And then the interaction between QDs and metal ions was studied after purifying the dBSA surface-modified QDs(dBSA-QDs).Experimental results showed that the conjugation of QDs by dBSA efficiently improved the photoluminescence quantum yield,the chemical stability of QDs and stability against photobleaching;meanwhile the fluorescence of dBSA-QDs can be quenched by heavy metal ions effectively,and the detection sensitivity was improved greatly compared with TGA-coated QDs.