Development Of Quantum Dot Based Immunochromatograghic Test Strips For The Detection Of Atrazine

In this study,quantum dots was selected as fluorescent label material,and two quantum dot immunochromatographic rapid test strips for the detection of atrazine were established.This method can be used for the rapid detection of actual samples.Atrazine coating antigen（Atrazine-OVA）was successfully prepared by the method of activating ester.The optimal working conditions were:The optimum pH value of the quantum dot-labeled antibody was 8.4;the molar ratio of Quantum dots to the EDC and antibody was 1:3000:8;the dilute time of coating antigen was 1:3;the dilute time of the second antibody was 1:280 the sample solution was PBS（pH=7.4）;working solution adding amount was 1.0 μL;the cellulose nitrate film（NC membrane）chose Millipore HF 135s;QDs-Ab compound adding amount was 0.5 μL.The limit detection of this test strip was 0.5 ng mL^-1,and detection time was 10 minutes.The limits of detection in the real samples were 0.5 ng mL^-1 for water samples and 2.5 ng mL^-1 for sugarcane juice samples and was 5 ng g-1 for corn.To other 8 kinds of structure similar triazine herbicide,only with propazine has cross reaction,can simultaneously detect three kinds of herbicides.The quantum dots fluorescence quenching test strip for atrazine,the best working conditions were:The optimum pH value of the quantum dot-labeled OVA was 8.4;the molar ratio of Quantum dots to the EDC and OVA was 1:3000:20;10 μl antibody was used to be labeled by 1mL gold nanoparticle,the best added amount of gold nanoparticle labeling antibody was 5 μL.On the test line,the blending ratio of costing antigen was 1:7.5;on the control line and the test line,the blending ratio of QDs-OVA and PBS was 1:5;the sample solution was PBS（pH 7.4）;the cellulose nitrate film（NC membrane）chose Millipore HF 135s.The limit detection of this test strip was 0.1 ng mL^-1,and detection time was 10 minutes.The limits of detection in the real samples were 0.1 ng mL^-1 for water samples and 0.5 ng mL^-1 for sugarcane juice samples and was 1 ng g^-1 for corn and.To other 8 kinds of structure similar triazine herbicide,only with propazine has cross reaction,can simultaneously detect three kinds of herbicides.There are some advantages in these two quantum dot immunochromatographic rapid test strips:samples’ preparations are simple and operations are easy;having good specificities and short detection times;there are higher sensitivities compared with traditional colloidal gold test strips;being suitable for rapid detections of a large number of samples in the field.