Research On Analysis Method Of Trace Endocrine Disruptors In Water Using Quantum Dots Marking Fluorescence Immunoassay

Taking bisphenol A (BPA)-a kind of typical endocrine disruptor as the studing object, the EDC and NHS active ester coupling method was adopted to label BPA haptens using the amino modified core-shell CdSe/ZnS quantum dots (QDs), and a fast and high sensitive detection method for BPA was established based on quantum dots/homogeneous phase direct competition fluoroimmunoassay. Under the optimized condition, the detection range for BPA is 1～104 ng/mL and the linear regression equation is F/Fo=-0.206LogC+0.824, the correlation coefficient (R2) is 0.995,50% of the fluorescent inhibition concentration is 39.98ng/mL, the coefficient of variation (CV) (n=5) is 3.91%, and the minimum detection limit is 0.46 ng/mL.50,500 and 5000 ng/mL BPA standards were added into tap water and sewage treatment plant water, the result shows that the adding recovery rates were 102.12%-112.85%,97.46%-109.66%,88.62%～96.25%, the respective coefficients of variation were 4.58%,4.61%,3.57% for tap water, also the adding recovery rates were 101.40%～107.65%,99.34%～112.61%,95.04%～104.42%, the respective coefficients of variation were 3.13%,6.29%,5.19% for sewage treatment plant water.The same method was applied to clenbuterol (CL)-another kind of typical endocrine disruptor. The detection range is 1～104 ng/mL, and the linear regression equation F/Fo=-0.196LogC+0.805, the correlation coefficient (R2) is 0.997,50% fluorescent inhibition concentration is 34.43 ng/mL, the coefficient of variation (CV) (n=5) is 7.34%, the minimum detection limit is 0.33 ng/mL.50,500 and 5000 ng/mL CL standards were added to lake water samples, and the result shows that the adding recovery rates were 95.01%～107.65%, 99.34%-112.61% and 90.45%～105.20%, the respective coefficients of variation (CV) (n=5) were 6.47%,4.96%,7.00%.In additon, the QDs labeled BPA antibody was acquired by labelling carboxyl modified CdSe/ZnS core-shell quantum dots (QDs) to the BPA polyclonal antibody using the EDC active ester method, a fast fluorescence immune chromatography detection method and corresponding detecting Kit for BPA were established. Results shows that minimum detecting limit for BPA detecting Kit was 0.01μg/mL with a testing time of 10-15min under the optimized condition.