Evaluation of the superparamagnetic and biological properties of microwave assisted synthesized Zn & Cd doped CoFe₂O₄ nanoparticles via Pechini sol–gel method

Recently, cobalt ferrite nanoparticles have attracted much attention due to their physical, chemical and magnetic properties. Numerous studies have focused on facile production of these nanoparticles. In this study, CoFe₂O₄, Zn_0.4Co_0.6Fe₂O₄, Cd_0.4Co_0.6Fe₂O₄, and Cd_0.2Zn_0.2Co_0.6Fe₂O₄ were successfully synthesized by using economical and simple microwave-modified Pechini sol–gel method, calcined by microwave radiation. The nanoparticles were characterized by some techniques such as X-ray diffraction, energy dispersive spectroscopy, field emission scanning electron microscopy, Fourier transform infrared, and vibrating sample magnetometer analyses. The X-ray diffraction, energy dispersive spectroscopy and Fourier transform infrared results confirmed the formation of CoFe₂O₄ nanoparticles. Fourier transform infrared indicated two fundamental absorption bands of spinel structure. The diameters of the spherical and rod form structures of nanoparticles ranged from 18 to 39 nm. The results indicated that the substitution of Co with Zn and Cd in cobalt ferrite influenced the physical properties, magnetic properties and cytotoxicity of these nanoparticles as medical devices. Zn doping had the significant effect on decreasing the size of cobalt ferrite nanoparticles and improving the magnetic properties. Zn-doped nanoparticles exhibited super paramagnetic behavior (coercivity was nearly 0oe and saturation magnetization was 52.78 emu/g). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (in vitro cytotoxicity MTT assay) assay confirmed that all samples were non-toxic and potentially can be used in biomedical application.