摘要
在水溶液中合成了巯基乙酸修饰的CdTe/CdS量子点(QDs),基于喹诺酮类抗生素司帕沙星与CdTe/CdS量子点的荧光猝灭作用,建立了用CdTe/CdS量子点作为荧光探针检测微量司帕沙星的新方法.用荧光光谱、紫外光谱研究了CdTe/CdSQDs与司帕沙星的相互作用.研究表明:该荧光猝灭的机理属于静态猝灭,反应的作用机理可能是司帕沙星促使QDs表面键合的有机分子发生变化,在Cd的电子空穴上形成了碲氧复合物,致使荧光猝灭.实验发现,pH为6.50的磷酸缓冲溶液中,量子点的浓度为3.75×10-4mol/L时,司帕沙星的浓度在0.1~50μg/mL范围与CdTe/CdS量子点荧光猝灭强度呈良好的线性关系,相关系数0.9992,检出限0.01399μg/mL.该方法简便、快捷、灵敏、线性范围宽,应用于司帕沙星片剂司帕沙星含量的测定,分析结果与标示量一致;用于牛奶中司帕沙星残留量的检测,回收率在93.1%~102.4%,结果满意.
The water-soluble CdTe/CdS quantum dots(QDs) was synthesized using mercaptoacetic acid as stabilizer.A novel method for determination of sparfloxacin(SPFX) has been developed based on quenching of the fluorescence of CdTe/CdS QDs at 580 nm by SPFX in aqueous solutions.Interaction of CdTe/CdS QDs synthesized in aqueous solution with sparfloxacin was studied by fluorescence spectrum and absorption spectrum.The mechanism of fluorescence quenching belongs to static quenching.IR spectrometer results indicated that the mechanism of the reaction was likely to be that the changes of surface-bound organic molecules of QDs,were induced by sparfloxacin,and the Te-oxygen complex was formed at the Cd surface vacancies.The optimum reaction conditions was found to be at pH 6.50 with phosphate buffer solution,and a CdTe/CdS QDs concentration of 3.75×10^-4 mol/L.The quenched fluorescence intensity of CdTe/CdS QDs was linearly proportional to the concentration of SPFX from 0.1 to 50 μg/mL with correlation coefficient r=0.9992,and the detection limit for SPFX was 0.01399 μg/mL.The amounts of SPFX in pill were determined by the proposed method and the results agreed with the claimed value.Trace amounts of SPFX in milk were also determined with the recovery of 93.1%~102.4%.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2010年第14期1437-1442,共6页
Acta Chimica Sinica
基金
广西自然科学基金(No728218)
广西研究生教育创新计划项目(No2009105960703M17)
桂林理工大学博士基金资助项目