Role of citric acid coating in enhancing applicability of CoFe2O4 nanoparticles in antibacterial and hyperthermia

Abstract

Citric acid-coated cobalt ferrite CoFe2O4 (CFO) nanoparticles (NPs) were synthesized via two-step procedures: Oleic acid (OA) coated CFO NPs by co-precipitation method and then a mechanochemical ligand exchanged with citric acid (CA). The successful fabrication of the CFO@CA sample was confirmed by the investigation of X-ray diffraction, and Fourier transform infrared spectroscopy. The significant impact of the CA coating led to the change in lattice parameter, crystallite size, and X-ray density of CFO@CA NPs as compared with pristine CFO NPs. In particular, the CFO@CA NPs have the smallest values of the crystallite size (12.4 nm) and the X-ray density (5.223 g/cm3), but they have the largest lattice parameter (8.423 Å). In addition, this CA coating improves their dispersion in water. Although this coating has almost no effect on the magnetic saturation of the CFO@CA sample (42.6 emu/g) as compared to the CFO sample (41.7 emu/g), their magnetic anisotropy (142.7 kJ/m3) was larger than that of other CFO samples. This led to a large specific absorption rate (135.2 W/g) and high antibacterial activity of the CFO@CA sample.