基于CdTe量子点荧光猝灭-恢复方法测定依诺沙星的研究

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

水相合成了巯基丙酸保护的CdTe量子点。根据在Cu^2＋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pH=10的硼砂缓冲溶液中,在Cu^2＋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%。

A new type of water-soluble Cd Te quantum dot was synthesized by using mercapto propionic acid as the capping ligand for the detection of enoxacin. The fluorescence intensity of Cd Te QDs was significantly quenched in the presence of Cu^2＋. In the presence of enoxacin,the fluorescence of Cd Te QDs was recovered because Cu^2＋preferred to react with enoxacin. The degree of recovery of Cd Te 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 Cd Te QDs. In the presence of 2. 3 × 10^- 5mol / L Cu^2＋in pH = 10 borax buffer solution,the recovered fluorescence of Cd Te QDs was linearly related with the enoxacin concentration in the range of 8. 0 × 10^- 7- 3. 0 × 10^- 5mol / L with a detection limit of 7. 2 × 10^- 8mol / L. This method has been successfully applied for the detection of enoxacin in real samples,and the accuracy is within95. 5%- 105. 0%.