Synthesis of magnetite/graphene oxide/chitosan composite and its application for protein adsorption

In this study, a facile and novel strategy was developed to fabricate magnetite/graphene oxide/chitosan (Fe3O4/GO/CS) composite, and the composite was used as a magnetic adsorbent for the enrichment of protein, and followed by matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF MS) analysis. The phase composition, chemical structure and morphology of the composite were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), transmission electron microscopy (TEM), scanning electronic microscope (SEM) and vibrating sample magnetometer (VSM). Protein cytochrome c was chosen as model target to evaluate the adsorptive property of Fe3O4/GO/CS. After enrichment procedure and magnetic separation, protein bounded with the material was analyzed by MALDI-TOF MS without desorption. The results indicated that Fe3O4/GO/CS composite exhibited a good adsorptive capacity for protein, and Fe3O4/GO/CS composite had a promising potential in magnetic separation research.