Development of an Enzyme-Linked Immunosorbent Assay to Carbaryl. 1. Antibody Production from Several Haptens and Characterization in Different Immunoassay Formats

With the aim of developing a highly sensitive immunoassay for the insecticide carbaryl, seven compounds were synthesized, conjugated to carrier proteins, and used as immunizing haptens in mice and rabbits. Polyclonal and monoclonal antibodies were subsequently obtained and characterized for their affinity to carbaryl. Three monoclonal antibodies (MAbs) that showed the highest affinity ( I 50 < 3.0 nM) were chosen for immunoassay development and further tested in the coating conjugate and coating antibody enzyme-linked immunosorbert assay (ELISA) formats, against both homologous and heterologous conjugates. Among several immunoassays developed, the combination of LIB-CNH36 MAb with the heterologous conjugate ovalbumin− N -(1-naphthoyl)-6-aminohexanoic acid in the coating conjugate ELISA format afforded the highest sensitivity for carbaryl determination ( I 50 = 1.1 nM). This work also provided some insights into the influence of the immunizing hapten structure on the affinity of the antibodies obtained, as well as into the effect of the ELISA format and hapten heterology on the assay sensitivity.