General immunoassay for pyrethroids based on a monoclonal antibody

For the development of class-specific antibody against pyrethroids, four haptens were designed and synthesised. A hybridoma 3E9 was successfully selected for production of antibody, which originated from mouse immunised with conjugates of hapten 1 [(RS)-cyano-3-phenoxybenzyl-2, 2, 3, 3-tetramethylcyclopropane-carboxylic acid] and keyhole limpet hemocyanin. A sensitive general immunoassay was developed with a monoclonal antibody from 3E9 cell line and coating antigen from conjugates of hapten 4 [N-(3-phenoxybenzoyl)-4-amino-L-phenylalanine] and bovine serum albumin. Under the optimised conditions, the antibody has good recognition to cypermethrin with 50% inhibition concentration (IC₅₀) value of 1.7±0.76 ng mL^?1. The cross-reaction to analogues was calculated as 12% for fenpropathrin, 4% for esfenvalerate. Besides, the antibody showed affinity to bifenthrin, deltamethrin and fenvalerate in different degrees with IC₅₀ value ranging from 191.8 to 298.5 ng mL^?1. The performance of this immunoassay was evaluated by fortified real water samples with three representative compounds. Recoveries were 76–118%, and the results showed that this immunoassay could be applied to monitor pyrethroid residues.