Polydopamine-based superparamagnetic molecularly imprinted polymer nanospheres for efficient protein recognition.

A new strategy for synthesis of superparamagnetic molecularly imprinted polymer nanospheres (MIPNSs) for efficient protein recognition is described here. Homogeneous hydroxyl group functionalized Fe3O4/polymethyl methacrylate (PMMA) composite nanospheres were prepared using improved miniemulsion polymerization. Uniform superparamagnetic MIPNSs were obtained via self-polymerization of dopamine (DA) on the surface of Fe3O4/PMMA composite nanospheres in the presence of lysozyme (lyz) template. The as-synthesized Fe3O4/PMMA/PDA MIPNSs had average diameters of 180 nm, high saturation magnetization and a good magnetic response. The lyz-imprinted Fe3O4/PMMA/PDA MIPNSs exhibited specific recognition and efficient adsorption capacity toward lyz template. The amount of lyz adsorbed onto the lyz-imprinted Fe3O4/PMMA/PDA MIPNSs was about 4 times greater than that of the Fe3O4/PMMA/PDA non-imprinted polymer nanospheres (NIPNSs) and about 14, 5, and 5 times greater than that of BSA, BHb, and cyt C, respectively.