A fluorescence polarization immunoassay method for detection of the bisphenol A residue in environmental water samples based on a monoclonal antibody and 4′-(aminomethyl)fluorescein

Abstract

Based on a sensitive monoclonal antibody against bisphenol A (BPA) and a new tracer named BVA–AMF, a homogeneous fluorescence polarization immunoassay (FPIA) was developed and applied in the determination of bisphenol A in environmental water samples. BVA was selected as the hapten to couple with bovine serum albumin and the conjugate was used as the immunogen for the monoclonal antibody production. Three fluorescein-labeled BVA tracers with different structures (BVA–AMF, BVA–EDF, and BVA–lysFITC) were synthesized. Under the same optimal conditions, BVA–AMF showed the highest sensitivity for FPIA and the detection of BPA exhibited a limit of detection of 5.60 ng mL⁻¹, an IC₅₀ of 140 ng mL⁻¹ and a dynamic range of 11.32–904.21 ng mL⁻¹ approximately. In this assay, several similar compounds were shown of little significantly with the cross-reactivity being less than 0.15%. Four different kinds of water samples were analyzed, with recoveries being 87.91–114.28%. The detection standard curve of BPA exhibited a good linearity (R² = 0.9913, n = 3). Compared with ELISA and HPLC methods, FPIA showed reliability and a high correlation with ELISA of 0.9964 and HPLC of 0.9971. The proposed immunoassay technique is suitable for detection of BPA in authentic environmental water samples.