Magnetic nanoparticles

containing a magnetic core and a polymer shell

were synthesized by coating magnetic fluid with chitosan. Novel affinity magnetic microspheres were obtained after immobilizing dye\|ligand (Cibacron Blue 3GA)onto the nanoparticles by covalent coupling. Under the preparation conditions

the microspheres had a spherical appearance

narrow distribution of diameter

and 14.5μmol/mL immobilization capacity for reactive dye. The microspheres can be separated by magnetic field. Bovine serum albumin (BSA) and lysozyme (Lys) were used as target proteins to examine the adsorption properties of the adsorbent. Under appropriate conditions

the adsorbent had a capacity of 4 and 28mg/g for BSA and Lys

respectively

Adsorption could be expressed by the Langmuir adsorption model.Unlike adsorption time

the liquid phase ionic strength affects the adsorption prperties dramatically.