Synthesis of gold-coated CoFe 2 O 4 and their potential in magnetic hyperthermia

CoFe2O4 nanoparticles (CFO) were synthesized via co-precipitation method and then gold coating (Au@CFO) was carried out by direct reduction of gold salt using citric acid and sodium citrate. Au coating was systematically observed by UV–Vis spectroscopy and afterwards confirmed by scanning electron microscopy, energy dispersive X-ray spectroscopy and Fourier-transform infrared spectroscopy. Gel electrophoresis was used to check the dispersive stability of Au@CFO dispersion which showed no agglomeration and indicated uniform size distribution. Magnetic characteristics before and after coating were studied via hysteresis loops which indicated reduction in magnetization of CFO after Au coating. Radio frequency (RF) heating measurements were done on powder and dispersed samples to evaluate their magnetic heating. Specific loss power was calculated from RF heating, which was greater for powdered samples than the dispersion of Au@CFO nanoparticles, but temperature can be controlled to reach the therapeutic range with respect to time and concentration.