Development of new magnetic nanoparticles: Oligochitosan obtained by γ-rays and –coated Fe₃O₄ nanoparticles

Highlights: • Oligochitosan was prepared by gamma irradiation method. • A new potential magnetic nanoparticles based on Fe₃O₄ coating with oligochitosan (Fe₃O₄@OCS) were successfully developed. • Spherical-shaped Fe₃O₄@OCS nanoparticles with superparamagnetic property and average diameter of approximately 14 nm were obtained. - Abstract: Oligochitosan (OCS) have been utilized as a potential bioactive material for improving food quality and human health. In this study, superparamagnetic iron oxide (Fe₃O₄) nanoparticles were originally coated with OCS irradiated by gamma rays for their possible biomedical applications. The formation of Fe₃O₄@OCS was characterized by Fourier transform infrared (FT-IR), X-ray diffraction patterns (XRD), energy dispersive X-ray spectroscopy (EDS) and thermogravimetric analysis (TGA). In addition, the superparamagnetic properties and sizes and morphologies of Fe₃O₄ and Fe₃O₄@OCS nanoparticles were demonstrated by vibrating sample magnetometer (VSM) and transmission electron microscopy (TEM), respectively. These results indicated that Fe₃O₄@OCS nanoparticles still maintained their superparamagnetic properties after polymeric coating, and were nearly spherical in shape with average diameter of 14.4 ± 0.31 nm, compared with 11.8 ± 0.52 nm of bare Fe₃O₄ nanoparticles, respectively. As a result, Fe₃O₄@OCS nanoparticles may serve as a promising platform for the development of new magnetic materials, which could be useful for biomedical applications.