Development of an enzyme-linked immunosorbent assay for the pyrethroid fenpropathrin

Abstract

An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) for the detection of fenpropathrin was developed. Two haptens, FPa (α-carboxy-3-phenoxyphenyl-2,2,3,3-tetramethyl-cyclopropane-carboxylate) and FPb (α-(N-butyrical)-3-phenoxybenzyl-2,2,3,3-tetramethyl-cyclopropane-carboxylate), were synthesised and conjugated with ovalbumin (OVA) by the mixed anhydride method as coating antigens (FPa–OVA and FPb–OVA), and the hapten FPb was conjugated to bovine serum albumin (BSA) by the carbodimide method to produce an immunogen (FPb–BSA). Polyclonal antibody against fenpropathrin was raised for screening the more sensitive coating antigen. Under optimised assay conditions, the 50% inhibitory concentration (IC50) was 0.34±0.090 mg/L and the limit of detection (LOD) was 0.0093±0.00065 mg/L. The cross-reactivities with other pyrethroids, such as deltamethrin, cypermethrin, fenvalerate and cyhalothrin, were all lower than 0.1%. Water samples spiked with different concentrations of fenpropathrin (0.01–1.0 mg/L) were analysed according to this method. The ic-ELISA developed could successfully be applied to residue analysis of fenpropathrin in aquatic.