中文摘要：

研究并构建了一种新型CdTe量子点＂开关＂,利用量子点荧光强度的变化进行痕量诺氟沙星的检测。考察了不同缓冲溶液,pH值,Co2＋浓度等因素对体系的影响。结果表明,在pH=10的硼砂缓冲液中,Co2＋能猝灭CdTe的荧光;体系中加入诺氟沙星后,CdTe的荧光得到恢复,并且量子点荧光的恢复强度与诺氟沙星的浓度与呈良好的线性关系。基于量子点＂开关＂技术,通过检测CdTe荧光恢复强度,建立了一种测定诺氟沙星的方法。方法的线性范围为0.8×10^-8～4.4×10^-7 mol/L;检出限为2.3×10^-9 mol/L。应用于实际样品的检测,RSD≤2.2%（n=6）,回收率为98.4%～102.1%,结果令人满意。

英文摘要：

A new type CdTe quantum dots （QDs） ＂switch＂ and its application in the determination of ultratrace norfloxacin was studied. The effect of different buffer solution, pH value and concentration of Co^2＋ were discussed in the experiment. The results showed that Co^2＋ could quenched the fluorescence intensity of CdTe in the Tris-HC1 buffer solution at pH = 10, after adding norfloxacin the fluorescence intensity recovered. There were good linear correlations between the concentrations of norfloxacin and the fluorescence recovered intensities. Then a new determination strategy of norfloxacin was built by using the CdTe QDs ＂switch＂. Under optimum conditions, the linear range of determining norfloxacin was 0. 8×10^-8- 4. 4 ×10^-7 mol/L, with a detection limit of 2. 3 ×10^-9 mol/L . This method was applied in the analysis of actual sample and the recoveries ranging from 98.4% to 102.1 were obtained.