Specific recognition of bovine serum albumin using superparamagnetic molecularly imprinted nanomaterials prepared by two-stage core–shell sol–gel polymerization
A novel type of uniform magnetic imprinted nanomaterial for the recognition of bovine serum albumin (BSA) was prepared by anchoring MIP shells on the surface of silica deposited Fe3O4 NPs via a surface imprinting process and two-stage core–shell sol–gel polymerization. The resulting magnetic nanomaterials were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and a vibrating sample magnetometer (VSM). The measurements indicated that the as-synthesized nanospheres exhibited good dispersion, high crystallinity, and satisfactory superparamagnetic properties. Moreover, the obtained Fe3O4@BSA–MIPs had a high saturation magnetization (43.82 emu g−1), which allowed them to be easily separated from solution by means of an external magnetic field. The thickness of the imprinted polymer layer was approximately 5 nm, which would be effective for the mass transport between the solution and the surface of Fe3O4@BSA–MIPs. The kinetic adsorption experiment showed that the imprinted nanomaterials could reach equilibrium within 15 min and be well described by the second-order kinetics model, indicating chemical adsorption might be the rate-limiting step. Meanwhile, the imprinting factor and selectivity coefficient of the Fe3O4@BSA–MIPs were as high as 16.4 and 4.65, displaying excellent selectivity towards BSA. In addition, the resulting imprinted polymers were without obvious deterioration after ten adsorption–desorption cycles and different batches of which exhibited excellent reproducibility. Successful application in the selective separation and enrichment of BSA from a bovine blood sample and good recovery after a reasonably mild elution suggested that the Fe3O4@BSA–MIPs could specifically capture BSA from a real complex matrix and had potential value in practical applications.