3-巯基丙酸修饰的CdSe/ZnS量子点的合成及测定牛血清白蛋白的研究

以3-巯基丙酸作为修饰剂,在水溶液中合成了稳定的CdSe/ZnS量子点(QDs),透射电镜观察所合成量子点的形貌近似球形,粒径约为25 nm.吸收光谱与荧光光谱的研究表明,CdSe QDs在410 nm处有最大吸收峰,而CdSe/ZnS QDs的最大吸收峰在470 nm处,CdSe/ZnS QDs的荧光强度是CdSe QDs的11倍.考察了缓冲溶液的体积、pH值、反应温度、反应时间对体系荧光的影响.在最佳实验条件下,体系的荧光强度与BSA的浓度呈线性关系,线性响应范围为0.746×10-7～4.48×10-7 mol/L,检出限为3.846×10-10 mol/L.并且CdSe/ZnS QDs荧光强度基本保持稳定,可达两个多月.该方法应用于合成样品的测定,结果满意.

Preparation of 3-Mercaptopropionic Acid Modified CdSe/ZnS QDs and Its Application to the Determination of BSA

CdSe/ZnS QDs have been synthesized in aqueous solution by using 3-mercaptopropionic acid(MPA) as stabilizer.The MPA modified CdSe/ZnS QDs were characterized using transmission electron microscopy.The result shows that the shape of CdSe/ZnS QDs is similar to spherical and the particle size is about 25 nm.It is demonstrated that the maximum absorption peak of CdSe/ZnS QDs is at 470 nm,while CdSe QDs's is at 410 nm,and the fluorescence intensity of CdSe/ZnS QDs is 11 times higher than CdSe QDs's.And the fluore...