Facile synthesis of a Ni(ii)-immobilized core-shell magnetic nanocomposite as an efficient affinity adsorbent for the depletion of abundant proteins from bovine blood.

In this study, a facile and efficient separation of abundant proteins from bovine blood using core-shell structure nanoparticles with a magnetic core and an immobilized metal affinity ligand iminodiacetic acid (IDA) chelating Ni(ii) is presented. Firstly, FeO magnetic nanoparticles (MNPs) were synthesized through a solvothermal method and then were conveniently surface-modified with 3-(methacryloyloxy) propyltrimethoxylsilane as anchor molecules to donate vinyl groups. Next a high density poly(4-vinylbenzylchloride) (PVBC) shell was synthesized on the surface of silica-coated FeO MNPs via distillation-precipitation polymerization. After the PVBC shell reacted with iminodiacetic acid (IDA) in alkaline aqueous solution, the magnetite was charged with Ni to form Ni(ii)-IDA functionalized hybrid FeO@PVBC@IDA-Ni MNPs. Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and a vibrating sample magnetometer (VSM) were employed to evaluate the size, morphology and magnetic property of the resulting magnetic nanospheres. The high saturation magnetization (48.1 emu g) provides the materials with the convenience of magnetic separation under an external magnetic field and they can be subsequently reused. The core-shell FeO@PVBC@IDA-Ni MNPs exhibit excellent performance in the separation of protein bovine hemoglobin (BHb), and the binding capacity is as high as 1988 mg g. In addition, the FeO@PVBC@IDA-Ni MNPs can be used in selective removal of abundant protein Hb in the bovine blood samples. This opens a novel route for its future application in removing abundant protein in proteomic analysis.