One-pot template-free synthesis of water-dispersive Fe3O4@C nanoparticles for adsorption of bovine serum albumin

Water-dispersive Fe3O4@C nanoparticles have been successfully synthesized on a large scale via a one-pot template-free solvothermal process. The core–shell structure of the product was confirmed by transmission electron microscopy (TEM) observations. Fourier transform infrared (FT-IR) and X-ray photoelectron spectra (XPS) of the sample indicated that abundant amide carbonyl groups are formed on the surface of the Fe3O4@C nanoparticles. Based on the thermogravimetric analysis (TGA) results, the contents of Fe3O4 and carbon are calculated to be 77.5% and 6.1%, respectively. Magnetic measurements illustrated that the prepared composites are superparamagnetic magnets with a saturation magnetization of 69.2 emu g−1. Because of their hydrophilic core–shell structure, the prepared Fe3O4@C nanoparticles show a high bovine serum albumin (BSA) protein adsorption capacity (82.78 mg g−1) and a fast adsorption rate (60 min) in aqueous solutions. This work demonstrates that the prepared magnetic nanoparticles have promising applications in enzyme and protein immobilization.