Preparation of Polyelectrolyte Brush Layer Modified Magnetic Particles for Separation of Proteins

Magnetic particles are a promising tool for separation of substantial proteins by applying an external magnetic field to collect the particles after adsorption of proteins. To provide much functionality on the magnetic particles for protein separation under mild condition and by easy procedures, polyelectrolyte brush layer was constructed on the surface. Magnetic polystyrene particles were prepared by mini-emulsion polymerization. Then the particles were modified with hydrophilic polyelectrolyte brush layer with different electric charges via atom transfer radical polymerization (ATRP). The polyelectrolyte brush layer could play an important role to endow the particles with good dispersion ability and also, control protein adsorption by electrostatic interaction. That is, the proteins having electric charges under biological environment could be adsorbed onto the magnetic particles with opposite-charged polymer brush layer and quickly collected from the solution. Thus we conclude that the magnetic particles with a polymer brush layer provide excellent functions. (paper)