Physicochemical and biological properties of iron and zinc ions co-doped nanocrystalline hydroxyapatite, synthesized by ultrasonication

Nanocrystalline hydroxyapatite (nHAp) co-doped with Fe3+ and Zn2+ ions, was prepared by the ultrasound assisted wet-chemical technique. The samples were characterized for their physicochemical properties by X-ray Diffraction (XRD), Fourier Transform Infrared spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), Scanning Electron Microscopy (SEM), and Vibrating Sample Magnetometry (VSM). Photoluminescence (PL) and dielectric properties were also investigated, in addition to the biological properties such as hemocompatibility, in vitro bioactivity and antimicrobial activity. The XRD patterns of pristine nHAp, and the Fe3+–Zn2+ ions co-doped HAp, confirmed the HAp phase. The TEM showed both spherical and rod-like morphology at higher dopant concentration (82 ppm Fe3+, 44 ppm Zn2+). The magnetization (Ms) and retentivity (Mr) were increased in the Fe3+–Zn2+ co-doped samples. The samples were having an enhanced superparamagnetic behavior. The co-doped samples are highly blood-compatible (<5% hemolysis), with high antimicrobial and in vitro bioactivity. The multifunctional properties of the samples enable them to be a promising candidate for biomedical applications.