Preparation of molecularly imprinted polymers and application in a biomimetic biotin-avidin-ELISA for the detection of bovine serum albumin.

Immunoassay as a primary analytical tool is widely applied in the field of analysis. However, biological antibodies used in the routine immunoassay exhibit high cost and poor stability. Herein, in this study, a biomimetic ELISA method using molecularly imprinted polymers as a alternative to antibodies was developed. The molecularly imprinted polymers were prepared through dopamine polymerization using Fe3O4 nanoparticles as magnetic nuclei, bovine serum albumin as a template, dopamine as a functional monomer and crosslinking agent. The molecularly imprinted polymers were characterized by scanning electron micrographs, transmission electron microscope, X-ray photoelectron spectroscopy, thermogravimetric analysis, vibrating sample magnetometer and X-ray diffractometer, respectively. The detection range of the established biomimetic ELISA method was 5-1000 µg mL-1. The method exhibited high selectivity for bovine serum albumin compared with other proteins and good recovery ranging from 89.0% to 102.3% was obtained from spiked bovine serum samples. The results showed that the method by using molecularly imprinted polymers as biomimetic antibodies could be used to detect bovine serum albumin rapidly in bovine serum with a high sensitivity and accuracy. This study demonstrates that the preparation of molecularly imprinted polymers by dopamine polymerization can produce material with high affinity and potential to replace antibodies in biomimetic ELISA for protein detection.

A novel surface molecularly imprinted polymer as the solid-phase extraction adsorbent for the selective determination of ampicillin sodium in milk and blood samples$ / 药物分析学报

Surface molecularly imprinted polymers (SMIPs) for selective adsorption of ampicillin sodium were synthesized using surface molecular imprinting technique with silica gel as a support. The physical and morphological characteristics of the polymers were investigated by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), elemental analysis and nitrogen adsorption–desorption test. The obtained results showed that the SMIPs displayed great adsorption capacity (13.5μg/mg), high recognition ability (the imprinted factor is 3.2) and good binding kinetics for ampicillin sodium. Finally, as solid phase extraction adsorbents, the SMIPs coupled with HPLC method were validated and applied for the enrichment, purification and determination of ampicillin sodium in real milk and blood samples. The averages of spiked accuracy ranged from 92.1%to 107.6%. The relative standard deviations of intra-and inter-day precisions were less than 4.6%. This study provides a new and promising method for enriching, extracting and determining ampicillin sodium in complex biological samples.