Development of an enzyme-linked immunosorbent assay for the organophosphorus insecticide bromophos-ethyl.
A competitive enzyme-linked immunosorbent assay (ELISA) was developed for the quantitative detection of the organophosphorus insecticide bromophos-ethyl. Four bromophos-ethyl derivatives (haptens) were synthesized and were coupled to carrier proteins through the pesticide thiophosphate group to use as an immunogen or as a coating antigen. Rabbits were immunized with either one of two haptens coupled to bovine serum albumin for production of polyclonal antibodies, and the sera were screened against one of the haptens coupled to ovalbumin. Using the serum with highest titer, an antigen-coated ELISA was developed, which showed an IC(50) of 3.9 ng/mL with a detection limit of 0.3 ng/mL (20% inhibition). An antibody-coated ELISA using an enzyme tracer was also developed, which showed an IC(50) of 6.5 ng/mL with a detection limit of 1.0 ng/mL (20% inhibition). The antibodies showed negligible cross-reactivity with other organophosphorus pesticides except with the insecticides bromophos-methyl and chlorpyrifos in the antibody-coated assay only. Recoveries of bromophos-ethyl from fortified crop and water samples ranged from 82 to 128% and from 95 to 127%, respectively.
Kim
Kwang-Ok
KO
Department of Food Science and Nutrition, Kyungpook National University, Daegu 702-701, Korea.
Kim
Yoo Jung
YJ
Lee
Yong Tae
YT
Hammock
Bruce D
BD
Lee
Hye-Sung
HS
D000818:Animals; D000918:Antibody Specificity; D001667:Binding, Competitive; D018556:Crops, Agricultural / Q000737:chemistry; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006241:Haptens / Q000276:immunology; D007106:Immune Sera; D007306:Insecticides / Q000032:analysis*; D063086:Organothiophosphates / Q000032:analysis* / Q000276:immunology; D011817:Rabbits; D014867:Water / Q000032:analysis
D006241:Haptens; D007106:Immune Sera; D007306:Insecticides; D063086:Organothiophosphates; D014867:Water; C100092:bromophos