Development Of The Quantum Dots Immunochromatographic Strip For The Detection Of Mycotoxin

In this paper, two immune chromatography strips were established for rapid detection of ochratoxin A and zearalenone in cereal samples, using quantum dots as signal probes,based on the principle of competitive immunoassay.Quantum dot-labeled anti-ochratoxin A antibody was prepared using the activated ester method. And the optimized working conditions were: the molar ratio of quantum dots:EDC:antibody is 1:1500:10; the optimum pH value for preparing quantum dot-labeled antibody was 8.3; coating antigen dilution ratio is 1:5; secondary antibody is diluted 250-fold by PB; Millipore HF135s were the most suitable cellulose nitrate film (NC membrane);samples were diluted by BBS solution (pH 8.3); loading buffer contains BBS solution (96 ?L), quantum dot-labeled ochratoxin A antibody (1 ?L) and working solution(3 ?L). The limit detection of ochratoxin A using this test strip was 0.5 ?g/L. There is no cross reaction with other types of mycotoxins, the method shows good specificity.Detection time is 10 minutes. And detection limits of ochratoxin A in samples were 4 or 5?g/kg.Quantum dot-labeled anti-zearalenone antibody was prepared using the activated ester method. And the best working conditions were: The molar ratio of Quantum dots: EDC:anti-zearalenone antibody is 1:1000:5; the optimum pH value for preparing quantum dot-labeled antibody was 8.3; coating antigen dilution ratio is 1:14; secondary antibody dilution ratio is 1:80; Millipore HF135s were the most suitable cellulose nitrate film (NC membrane); samples were diluted by PBS solution (pH 7.4); loading buffer were the mixture of PBS solution (94 ?L), quantum dot-labeled zearalenone antibody (1 ?L) and working solution (5 ?L). The limit detection of zearalenone using this test strip was ?g/L.And it shows cross reaction with 5 kinds of its structural analogue. Detection time is 10 minutes. The detection limits of zearalenone in samples were 10 ?g/kg.The established rapid immunochromatographic strip shows advantages of high sensitivity,good specificity, convenient sample preparation, saving time and easy recognization of results, which was suitable for field tests.