BPA Endocrine Disruptor Detection at the Cutting Edge: FPIA and ELISA Immunoassays

Abstract

BPA is a chemical commonly used in the production of polymer-based materials that can have detrimental effects on the thyroid gland and impact human reproductive health. Various expensive methods, such as liquid and gas chromatography, have been suggested for detecting BPA. The fluorescence polarization immunoassay (FPIA) is an inexpensive and efficient homogeneous mix-and-read method that allows for high-throughput screening. FPIA offers high specificity and sensitivity and can be carried out in a single phase within a timeframe of 20–30 min. In this study, new tracer molecules were designed that linked the fluorescein fluorophore with and without a spacer to the bisphenol A moiety. To assess the influence of the C6 spacer on the sensitivity of an assay based on the respective antibody, hapten–protein conjugates were synthesized and assessed for performance in an ELISA setup, and this resulted in a highly sensitive assay with a detection limit of 0.05 g/L. The lowest limit of detection was reached by employing the spacer derivate in the FPIA and was 1.0 μg/L, working range from 2 to 155 μg/L. The validation of the methods was conducted using actual samples compared to LC–MS/MS, which served as the reference method. The FPIA and ELISA both demonstrated satisfactory concordance.

Detection of Dibutyl Phthalate in Surface Water by Fluorescence Polarization Immunoassay

“…For the development of a highly sensitive FPIA assay, the quality of the immunoreagents plays an important role [54,55]. A special role is assigned to the conjugate of a low molecular weight analyte with a fluorescent label-a tracer [56].…”

“…In this work, to obtain DBP tracers with fluorescein derivatives, two haptens were used, 4-amino-DBP and 4-succinate-DBP, which have different functional groups, NH 2 -and -COOH, respectively. Therefore, to obtain tracers, DTAF and 5-AMF were used, which react with these haptens [54,55]. Note that the structures of DBP-AMF and DBP-DTAF (Figure 1) tracers differ in such parameters as length and rigidity of the spacer between fluorescein and DBP.…”