基于CdTe量子点荧光猝灭法测定水体中结晶紫

Determination of Crystal Violet in Water by Fluorescence Quenching Method Based on CdTe Quantum Dots

以巯基乙酸为稳定剂,用水热法合成CdTe量子点（QDs）,基于结晶紫对CdTe QDs的荧光猝灭作用,建立一种新的测定结晶紫含量的新方法。在优化实验条件下,结晶紫浓度在1.0~10.0μmol·L^-1范围内与CdTe QDs的荧光猝灭程度呈良好的线性关系,相关系数r=0.9986,检出限为0.026μmol·L^-1。该方法用于水样中结晶紫含量的测定,加标回收率为96.2%~103.1%。同时,对结晶紫和CdTe QDs之间的反应机理进行探讨,发现CdTe QDs的发射光谱与结晶紫的吸收光谱能够有效重叠,且二者通过静电作用结合,可建立以CdTe QDs为供体,结晶紫为受体的荧光共振能量转移体系。

The water-soluble CdTe quantum dots（QDs）were synthesized using thioglycolic acid（TGA）as stabilizer agents.Based on the fluorescence quenching of CdTe QDs caused by crystal violet（CV）,a new method for the determination of CV was developed.Under the optimal conditions,the quenched fluorescence intensity of CdTe QDs showed a good linearity over the concentration of CV in the range of 1.0-10.0μmol·L^-1.The correlation coefficient was 0.9986 and the limit of detection was 0.026μmol·L^-1.The proposed method was successfully applied in the determination of CV in water samples with spiked recoveries of 96.2%-103.1%.Furthermore,the possible fluorescence quenching mechanism was discussed.An appreciable over lap between the emission spectrum of CdTe QDs and the absorption spectrum of CV was found.Moreover,CV could bind the CdTe QDs through electrostatic force.Thus,the fluorescence resonance energy transfer（FRET）system was constructed between CdTe QDs（donor）and CV（acceptor）,which resulted in fluorescence quenching.