Photoluminescent Hydroxylapatite: Eu 3+ Doping Effect on Biological Behaviour.

Luminescent europium-doped hydroxylapatite (Eu _X HAp) nanomaterials were successfully obtained by co-precipitation method at low temperature. The morphological, structural and optical properties were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X -ray diffraction (XRD), Fourier Transform Infrared (FT-IR), UV-Vis and photoluminescence (PL) spectroscopy. The cytotoxicity and biocompatibility of Eu _X HAp were also evaluated using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)) assay, oxidative stress assessment and fluorescent microscopy. The results reveal that the Eu ³⁺ has successfully doped the hexagonal lattice of hydroxylapatite. By enhancing the optical features, these Eu _X HAp materials demonstrated superior efficiency to become fluorescent labelling materials for bioimaging applications.