基于CdTe量子点荧光猝灭-恢复方法测定依诺沙星的研究

水相合成了巯基丙酸保护的CdTe量子点。根据在Cu2+存在的情况下,CdTe量子点荧光恢复程度与依诺沙星浓度成正比的现象,建立了基于CdTe量子点荧光猝灭-恢复测定依诺沙星的新方法。考察了溶液pH值以及Cu2+浓度等对检测体系的影响。在p H=10的硼砂缓冲溶液中,在Cu2+浓度为2.3×10-5mol/L的条件下,依诺沙星浓度在8.0×10-7~3.0×10-5mol/L范围内与量子点荧光恢复程度呈良好的线性关系,检出限为7.2×10-8mol/L。该方法用于实际样品中依诺沙星的检测,回收率为95.5%~105.0%。

Enoxacin Detection Based on CdTe Quantum-dot-based OFF-ON Fluorescent Probe

A new type of water-soluble CdTe quantum dot was synthesized by using mercapto propi-onic acid as the capping ligand for the detection of enoxacin. The fluorescence intensity of CdTe QDs was significantly quenched in the presence of Cu2+. In the presence of enoxacin,the fluores-cence of CdTe QDs was recovered because Cu2+ preferred to react with enoxacin. The degree of re-covery of CdTe QDs fluorescence intensity was proportional to the enoxacin concentration, which provided a new method for the detection of enoxacin based on the fluorescence quenching-recovery properties of CdTe QDs. In the presence of 2. 3 í10 -5 mol/L Cu2+ in pH=10 borax buffer solu-tion, the recovered fluorescence of CdTe QDs was linearly related with the enoxacin concentration in the range of 8. 0í10 -7 -3. 0í10 -5 mol/L with a detection limit of 7. 2í10 -8 mol/L. This meth-od has been successfully applied for the detection of enoxacin in real samples, and the accuracy is within 95 . 5% -105 . 0%.