中文摘要：

以羧甲基纤维素钠（CMC）为稳定剂,在水相中制备了CdS量子点,基于Cu2＋离子对量子点荧光的猝灭作用,建立了定量测定Cu2＋离子的新方法。CdS量子点对铜离子呈现出高选择性,除Co2＋和Hg2＋离子外,其它常见金属离子的存在对铜的测定几乎不产生干扰。考察了不同缓冲体系及缓冲液pH值、量子点浓度、反应时间和反应温度等因素的影响,确定了Cu2＋离子的最佳分析条件,即pH=5.6,磷酸氢二钠-磷酸二氢钾缓冲溶液的浓度为0.033 mol/L,量子点的浓度为2.0×10-4mol/L。在最佳条件下,量子点的相对荧光强度与Cu2＋离子的浓度呈很好的线性关系,该方法的线性范围为5.0×10-8～2.0×10-5mol/L,线性回归方程为：F0/F=1.015 0＋10 0791.6c,检出限为8.0×10-9mol/L。本方法简单、快速,与文献报道的其它基于量子点荧光探针Cu2＋离子分析方法相比,此法对Cu2＋离子呈现出更高的选择性且具有更宽的线性检测范围。将此法用于水样和人体头发等实际样品中Cu2＋离子含量的测定,结果令人满意。

英文摘要：

A new protocol for the determination of copper was developed based on the fluorescence quenching of carboxymethyl cellulose（CMC） coated CdS quantum dots（QDs）,which were synthesized in aqueous solution using environmental benign carboxymethyl cellulose as stabilizer.The method has a relatively high selectivity,and no obvious interference on the determination of copper from other coexisting metal ions is observed except Co2＋ and Hg2＋ ions.Some influencing factors,including the buffer system,pH of the solution,concentration of QDs,reacting time and the temperature of reaction have also been investigated to obtain the optimal conditions for copper determination.When the concentration of QDs was 2×10-4 mol/L,the concentration of KH2PO4-Na2HPO4 is 0.033 mol/L at pH=5.6,the relative fluorescence intensity of QDs was linearly proportional to copper（Ⅱ） ion concentration in the range from 5×10-8 to 2×10-5 mol/L.The linear equation was F0/F=1.0150＋100791.6c,and the detection limit was 8×10-9 mol/L.This method is simple and rapid.Compared with the methods reported using QDs as fluorescence probes,this method has a higher selectivity and a wider linear range.The proposed method has been applied to the determination of trace copper in water and human hair with satisfactory results.