Immunoprecipitation of bisphenol A by antibody–mesoporous silica composites

Bisphenol A (BPA) is of global concern because of its disruption of endocrine systems and ubiquity in aquatic environment. In this study, BPA antibody was successfully immobilised on novel mesoporous silica (MPS) carriers that display unique properties such as high surface area, highly uniform pore distribution and high adsorption capacity. Mobil Crystalline Material MCM-41 (2.7 nm), Santa Barbara Amorphous SBA-15-1 (12.3 nm) and SBA-15-2 (24.0 nm) materials were used as supports for these antibodies. On these carriers, the BPA antibody immobilisation reached 40 μg mg−1. For each MPS, 15 ng of BPA antigen was adsorbed on 1 mg of MPS–antibody composite, which resulted in an antibody activity of 30%. The highest recovery rate of BPA antigen was observed for 80% acetonitrile in 10 mM phosphate buffer (pH 7). After six repeated runs, BPA antibodies immobilised on SBA-15-1 and SBA-15-2 retained about 30% of their initial activity. In contrast, these antibodies showed 13% lower residual activity on MCM-41 than on SBA-15-1 and SBA-15-2. This result indicated that entire antibody molecules were adsorbed inside SBA-15-1 and SBA-15-2 pores, stabilising their structural conformation.