Affinity adsorption of albumin on Cibacron Blue F3GA-coupled non-porous micrometer-sized magnetic polymer microspheres

Non-porous micrometer-sized magnetic polymer microspheres were prepared for affinity protein adsorption utilizing Cibacron Blue F3GA as a dye ligand. Magnetic poly (styrene-divinylbenzene-glycidyl methacrylate) (PSt-DVB-GMA) microspheres were prepared by a modified suspension polymerization method. The magnetic microspheres were modified with ethylenediamine by ring-opening reaction of epoxy groups to produce surface functional amino groups. Then, Cibacron Blue F3GA was covalently immobilized onto the above magnetic microspheres for bovine serum albumin (BSA) adsorption from aqueous solution. Scanning electron microscopy showed that the magnetic microspheres had an average size of 6 μm and magnetic measurement revealed they were superparamagnetic with saturation magnetization of 7.3 emu/g. Albumin adsorption showed that the dye ligand attached magnetic microspheres had high adsorption capacity of BSA (80.2 mg/g) and low non-specific adsorption (<10 mg/g). The adsorption conditions, such as pH, ionic strength and initial concentration of BSA were investigated. Desorption of BSA was obtained using 1 M NaSCN solution.