基于量子点荧光探针的重金属离子Hg2+检测方法

Detection Method of Heavy Metal Ions Hg2+ Based on Quantum Dots Fluorescence Probe

以重金属离子Hg^2+为研究对象,使用经过L-半胱氨酸修饰的CdTe量子点溶液对Hg2+进行检测,Hg2+与表面采用修饰剂的量子点结合使得量子点发生荧光猝灭现象,Hg^2+浓度与荧光猝灭的变化强度呈一定的线性关系,利用这种线性关系实现量子点对溶液中Hg^2+含量的定量检测,检测波段为400~800nm。在优化条件下测得方法检出限为6.11×10^-9mol/L(S/N=3,n=11),线性范围为9×10^-9~5×10^-6mol/L,相对标准偏差(RSD)为2.86%。在实验环境下,对特征波段进行变量标准化(SNV)预处理,再进行偏最小二乘(PLS)建模分析,得到较好的自预测能力和实际预测能力,其中校正集的决定系数为0.8784,RMSEC为11.6313μmol/L,验证集的决定系数为0.7287,RMSEP为18.7174μmol/L。结果表明,实验建模效果良好,操作简单、方便,实验快速、可靠、无污染,表明利用量子点荧光探针检测Hg^2+方法可行。

The subject of this experiment was Hg^2+,Hg^2+ was detected by L-cysteine-modified CdTe quantum dot solution,and Hg^2+ was combined with the surface-modified quantum dots to cause fluorescence quenching of quantum dots,Hg^2+ concentration and fluorescence.The intensity of annihilation had a linear relationship.This linear relationship was used to quantitatively detect the Hg^2+ content in the solution by quantum dots.The detection band was 400~800 nm.The detection limit of the method under optimized conditions was 6.11×10^-9 mol/L ( S/N =3,n =11),and the linear range was 9×10^-9 ~5×10^-6 mol/L.The deviation (RSD) was 2.86%.In a certain experimental environment,the variable normalization (SNV) pre-processing of the characteristic band and the partial least squares (PLS) modeling analysis can obtain better self-prediction ability and actual prediction ability,and the determination coefficient of the correction set reached 0.878 4.The standard deviation was 11.631 3 μmol/L,the determination coefficient of the validation set was 0.728 7,and the standard deviation was 18.717 4 μmol/L.The results showed that the modeling effect was good,the operation was simple and convenient,the experiment was fast,reliable and non-polluting,which indicated that the method of detecting Hg 2+ by quantum dot fluorescent probe was feasible.