Liang Jian-Gong, Ai Xin-Ping, He Zhi-Ke, Pang Dai-Wen
College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, P. R. China.
Analyst. 2004 Jul;129(7):619-22. doi: 10.1039/b317044f. Epub 2004 Apr 20.
CdSe quantum dots (QDs) have been prepared and modified with mercaptoacetic acid. They are water-soluble and biocompatible. To improve their fluorescence intensity and stability in water solution, bovine serum albumin (BSA) was absorbed onto their surface. Based on the quench of fluorescence signals of the functionalized CdSe QDs in the 543 nm wavelength and enhancement of them in the 570-700 nm wavelength range by Ag(I) ions at pH 5.0, a simple, rapid and specific method for Ag(I) determination was proposed. In comparison with single organic fluorophores, these nanoparticles are brighter, more stable against photobleaching, and do not suffer from blinking. Under the optimum conditions, the response is linearly proportional to the concentration of Ag(I) between 4.0 x 10(-7) and 1.5 x 10(-5) mol L(-1), and the limit of detection is 7.0 x 10(-8) mol L(-1). The mechanism of reaction is also discussed.
硒化镉量子点（QDs）已被制备并用巯基乙酸进行了修饰。它们具有水溶性和生物相容性。为了提高其在水溶液中的荧光强度和稳定性，牛血清白蛋白（BSA）被吸附到其表面。基于在pH 5.0条件下，Ag(I)离子对功能化硒化镉量子点在543 nm波长处荧光信号的猝灭以及在570 - 700 nm波长范围内荧光信号的增强，提出了一种简单、快速且特异的Ag(I)测定方法。与单一有机荧光团相比，这些纳米颗粒更亮，对光漂白更稳定，且不存在闪烁现象。在最佳条件下，响应与Ag(I)浓度在4.0×10⁻⁷至1.5×10⁻⁵ mol L⁻¹之间呈线性比例关系，检测限为7.0×10⁻⁸ mol L⁻¹。同时还讨论了反应机理。
