基于CdTe/CdS量子点荧光淬灭方法检测自来水和果汁中汞离子

本文基于巯基乙酸修饰的核壳型CdTe/CdS量子点建立了Hg2+的检测方法。对检测条件进行优化并利用荧光光谱仪和紫外-可见吸收光谱仪对量子点荧光强度进行表征。结果表明:在Tris-HCl缓冲溶液浓度为0.05 mol/L,pH8.0,室温反应15 min的条件下,不同浓度Hg2+(10-6~10-4 mol/L)对量子点具有较好的荧光猝灭效果,且随着Hg2+溶液浓度增加,其对量子点的荧光猝灭效果逐渐增强。该方法对Hg2+的理论检出限为2.667 nmol/L,低于自来水检测标准;对果汁样品中Hg2+的检测灵敏度为2.0×10-5 mol/L。因此,本研究为果汁体系中重金属的检测提供了一种新的思路和方法。

Detection of Hg2+ in Tap Water and Fruit Juice Based on CdTe/CdS Quantum Dots

In this study,the detection method of Hg2+ was established based on mercaptoacetic acid-modified core-shell CdTe/CdS quantum dots. The fluorescence intensity of quantum dots was characterized by fluorescence spectrometer and UV-Vis absorption spectrometer. The results showed that,when the optimum reaction conditions of Tris-HCl buffer solution with the concentration of 0.05 mol/L,pH8.0 and reaction for 15 min,Hg2+(10-6~10-4 mol/L)at different concentrations had a good fluorescence quenching effect on the quantum dots. The theoretical detection limit of Hg2+ by this method was 2.667 nmol/L,which was lower than the detection standard of tap water. For the fruit juice samples,the detection limit was 2.0×10-5 mol/L. Therefore,the study provided a new insight and method for the detection of heavy metals in juice system.