Preparation and characterization of surface molecularly imprinted films coated on multiwall carbon nanotubes for recognition and separation of lysozyme with high binding capacity and selectivity

In this work, a series of facile and efficient molecularly imprinted polymers (MIPs) for the selective recognition and separation of lysozyme were synthesized by combining self-polymerization and nanosized matrix. The imprinted materials containing recognition sites for the lysozyme were formed via using both carboxyl-functionalized multi-walled carbon nanotubes (MWCNTs-COOH) as a support and dopamine (DA) with excellent biocompatibility as a functional monomer. The obtained polymers were characterized and evaluated by using field-emission scanning electron microscopy (FESEM), field-emission transmission electron microscopy (FETEM), nitrogen physisorption experiments, Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analysis (TGA). The optimum reaction conditions and adsorption performance of the resultant nanomaterials were also investigated. MIPs synthesized by this method exhibited excellent imprinting factor (4.1) and high binding capacity (418 mg g(-1)) for lysozyme. After six adsorption-desorption cycles, the adsorption capacity of the MIPs was only reduced by 7.4%. In addition, the prepared MIPs were used to separate and condense lysozyme from chicken egg white successfully, which showed potential values in industrial protein purification, basic biomedical research and clinical diagnostics.