QI Mingxing;YANG Pu;ZOU Ling;SUN Ming;College of Information and Electrical Engineering,China Agricultural University;Beijing Engineering and Technology Research Center for Internet of Things in Agriculture;

Hg2+ detection;;quantum dot;;fluorescent probe;;spectral analysis

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 3μmol/L,the determination coefficient of the validation set was 0.728 7,and the standard deviation was 18.717 4μmol/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.