基于CdSeTe/ZnS量子点荧光探针测定痕量As^(3+)

A new fluorescence probe for detection of As^(3+) ions based on glutathione-capped CdSeTe/ZnS quantum dots

水相合成高荧光量子产率的谷胱甘肽(GSH)包覆CdSeTe/ZnS量子点,并通过紫外光谱(UV)、荧光光谱(PL)、透射电镜(TEM)和电子衍射(XRD)等手段对其光学特性和结构进行表征。基于CdSeTe/ZnS量子点表面GSH对As^(3+)的特异性结合而导致量子点荧光猝灭作用,构建了基于CdSeTe/ZnS量子点作为荧光探针检测痕量As^(3+)的新方法。探究了As^(3+)对CdSeTe/ZnS量子点荧光猝灭的机理,As^(3+)在5.0~100.0μg/L浓度范围内,CdSeTe/ZnS量子点的荧光强度F_0/F与As^(3+)浓度之间呈良好的线性关系,线性相关系数为0.9984,检测限为1.0μg/L。该量子点荧光分析方法可用于实际水样中As^(3+)的检测。

Water-soluble CdSeTe/ZnS quantum dots （QDs） were synthesized with glutathione （GSH） as stabilizer. Their optical features and structure have been characterized by UV-Visible spectroscopy, photoluminescence （PL） spectroscopy, transmission electron microscopy （TEM） and X-ray diffraction （XRD） in detail. The as-prepared CdSeTe/ZnS QDs were directly used as a recognition probe for the detection of As^3＋ because of the strong interactions between As^3＋ and the GSH molecule of CdSeTe/ ZnS QDs. Under optimal conditions, the quenched fluorescence intensity （Fo/F） increased linearly with the concentration of As^3＋ ranging from 5.0 to 100 μg/L. The limit of detection （3σ） for As^3＋ was found to be 1 μg/L. The practical application had been carried out for determination of As^3＋ in real water samples.