Research on an Enzyme linked Immunosorbent Assay for Dichlorodiphenyltrich loroethane,Endosulfan and Isocarbophos Based on Monoclonal Antibodies

KeyWord:indirect competitive enzyme-linked immunosorbent assay  dichlorodiphenyltrichloroethane  endosulfan  isocarbophos  pesticide residue  monoclonal antibody

Abstract:

      Development of detection techniques for pesticide residues such as dichlorodiphenyltrichloroethane(DDT),endosulfan and isocarbophos is of great importance to ensure the safety of agricultural products and environment due to their high toxicity.Meanwhile,immunoassay has the advantages of economy and simplicity in the rapid detection of a large number of samples.In this paper,anti-DDT,anti-endosulfan and anti-isocarbophos monoclonal antibodies were prepared.An indirect competitive enzyme-linked immunosorbent assay(ic-ELISA) for the pesticides was developed with a commercial horse radish peroxidase-labeled goat anti-mouse antibody as secondary antibody.Under optimal conditions,the 50% inhibitory concentrations and detection limits of the method for DDT,endosulfan and isocarbophos were 10.72 ng¡¤mL-1 and 1.85 ng¡¤mL-1,9.69 ng¡¤mL-1 and 2.19 ng¡¤mL-1,13.26 ng¡¤mL-1 and 3.04 ng¡¤mL-1,respectively.The ic-ELISA for DDT showed that the cross-reactivities(CRs) of DDT with o,p-2,2-bis(4-chlorophenyl)-1,1-dichloroethylene(DDE),p,p-DDE and o,p-DDT were in the range of 9.0%-33.4%.The ic-ELISA for endosulfan showed that CRs of endosulfan with aldrin,chlordane,dieldrin,¦Â-endosulfan and ¦Á-endosulfan were in the range of 17.4%-84.3%.The ic-ELISA for isocarbophos showed that isocarbophos had no significant CR with its six analogues(CR£¼0.1%).The average recoveries of the ic-ELISA for DDT,endosulfan and isocarbophos in paddy water,soil,apple and banana samples were in the ranges of 71.4%-93.3%,74.0%-97.4% and 70.8%-97.0%,with relative standard deviations of 3.8%-9.6%,3.0%-11% and 4.2%-12%,respectively.Meanwhile,the results of ic-ELISA showed good correlations with those of chromatography in the detection of DDT,endosulfan and isocarbophos.The related results showed that the monoclonal antibodies of DDT,endosulfan and isocarbophos prepared in this study could be used to establish an ic-ELISA with good sensitivity and accuracy.