title: Competitive immunochromatographic assay for the detection of the organophosphorus pesticide chlorpyrifos.
abstract: An immunochromatographic assay (ICA) based on competitive antigen-coated format using colloidal gold as the label was developed for the detection of the organophosphorus insecticide chlorpyrifos. The ICA test strip consisted of a membrane with a detection zone, a sample pad and an absorbent pad. The membrane was separately coated with chlorpyrifos Hapten-OVA conjugate (test line) and anti-mouse IgG (control line). Based on the fact that the competition is between the migrating analyte in the sample and the analyte hapten immobilized on the test strip for the binding sites of the antibody-colloidal gold (Ab-CG) conjugate migrating on the test strip, this study suggests that the relative migration speed between the two migrating substances is a critically important factor for the sensitive detection by competitive ICA. This criterion was utilized for the confirmation of appropriateness of a nitrocellulose (NC) membrane for chlorpyrifos ICA. The detection limit of the ICA for chlorpyrifos standard and chlorpyrifos spiked into agricultural samples were 10 and 50 ng mL(-1), respectively. The assay time for the ICA test was less than 10 min, suitable for rapid on-site testing of chlorpyrifos.
authors.affiliation: Department of Food Science and Nutrition, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Young Ah
authors.initials: YA
authors.lastname: Kim
authors.forename: Eun-Hye
authors.initials: EH
authors.lastname: Lee
authors.forename: Kwang-Ok
authors.initials: KO
authors.lastname: Kim
authors.forename: Yong Tae
authors.initials: YT
authors.lastname: Lee
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Hammock
authors.forename: Hye-Sung
authors.initials: HS
authors.lastname: Lee
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001665:Binding Sites; D001667:Binding, Competitive; D004390:Chlorpyrifos / Q000032:analysis* / Q000302:isolation & purification; D003101:Collodion / Q000737:chemistry; D003429:Cross Reactions; D006046:Gold / Q000737:chemistry; D006241:Haptens / Q000737:chemistry; D007118:Immunoassay / Q000379:methods*; D007306:Insecticides / Q000032:analysis* / Q000302:isolation & purification; D051379:Mice; D010047:Ovalbumin / Q000737:chemistry
chemical_list: D000911:Antibodies, Monoclonal; D006241:Haptens; D007306:Insecticides; D006046:Gold; D003101:Collodion; D010047:Ovalbumin; D004390:Chlorpyrifos