In Ukrainian

Abstract

The aim of the work is the synthesis of nanodispersed phosphors based on lanthanum fluoride and phosphate, activated by terbium (LaF3:Tb3+ and LaРО4:Tb3+, respectively), promising for use in photodynamic therapy and optopharmacology, the study of their structural properties and luminescence spectra when excited by ultraviolet and X-ray radiation, as well as the possibility of their use in the composition of nanocomposites with magnetically sensitive nanosized Fe3O4 carriers and bioactive glass 60S. Nanocrystalline lanthanum fluoride and phosphate of hexagonal syngonium were synthesized, activated with terbium. The structural properties, chemical activity and biocompatibility of the surface, UV and X-ray luminescence spectra of the synthesized crystals were studied. The possibility of their use in the composition of nanocomposites with magnetically sensitive nanosized drug carriers and bioactive sol-gel glass is shown. The acid-base nature of the surface active centers of LaF3 and LaF3:Tb3+ NPs has been revealed. The proportions of negatively a––, positively a+ charged and neutral a0 active centers were calculated in the range of pH 2.4 – 12.7. The identified active surface centers can be represented by acidic (La3+) and basic (F-) Lewis centers, as well as basic Brønsted centers (OH- groups). The obtained data can be useful in optimizing the conditions of adsorption immobilization from a physiological solution of molecules of photosensitive substances (sensitizers) on the surface of phosphors based on lanthanum fluoride. Ensembles of particles of magnetically sensitive Fe3O4/LaF3:Tb3+ NCs of core-shell type were synthesized. The conditions of synthesis of NCs did not significantly change the magnetic properties of their cores – the initial single-domain Fe3O4 NPs. Composites of bioglass 60S with nanodispersed crystalline LaF3:Tb3+ and LaPO4:Tb3+ in the dry state and in distilled water medium demonstrated the presence of luminescence when excited by UV and X-ray radiation. The given data indicate the prospects of research of nanodispersed phosphors based on lanthanum fluoride and phosphate, their composites with magnetically sensitive nanosized carriers and bioactive glass, for use in optopharmacology and photodynamic therapy of tumor diseases, in particular, localized in organs of skull and bone tissues. In addition, research results can be useful for technical applications, in particular, in the creation of fluorescent detectors of high-energy electromagnetic radiation, development of photo- and optoelectronic devices, etc.