中文摘要：

合成了新型巯基化壳聚糖,并采用一步法合成了巯基化壳聚糖包覆的水溶性CdS量子点（QDs）。结果表明制备的巯基化壳聚糖包覆CdS QDs粒径均匀,该量子点在水溶液中稳定性好并且Hg^2＋对其荧光具有明显的猝灭作用。在最佳测定条件下,标准曲线的线性范围为3.0×10^-7~5.0×10^-5 mol/L,检出限为5.3×10^-8 mol/L,且方法抗干扰性好,日内及日间精密度在5.8%之内。该方法应用于实际水样检测,回收率在86.4%~104.6%之间。

英文摘要：

The synthesis method of thiolated chitosan coated CdS quantum dots（QDs）has been developed through a one-step process.The characterization results show that the size distribution of the synthesized QDs is relatively uniform.The thiolated chitosan coated CdS possess high photostability in aqueous solution.The significant fluorescence quenching effect can be observed in the presence of Hg^2＋.Under the optimum conditions,the fluorescence quenching of the thiolated chitosan coated CdS QDs is linearly proportional to the concentration of Hg^2＋ in the range of 3.0×10^-7-5.0×10^-5 mol/L.The detection limit of Hg^2＋ was 5.3×10^-8 mol/L（S/N=3）.The intra-day and inter-day precision indicated by RSD are both less than 5.8%（n=6）.The recoveries of the proposed method in real water samples are between 86.4% and 104.6%.