Hubenko K. Optical spectroscopy of the electron excitation energy transfer in hybrid organo-inorganic complexes based on ReVO4 (Re = Gd, Y, Eu) and CaWO4 nanoparticles

Object of the study: mechanisms of interaction between nanoparticle and photosensitizer organic molecules in aqueous solutions and mesoporous nanocontainers. Objective: study of physical mechanisms of nonradiative electron excitation energy transfer between inorganic nanoparticles and photosensitizer organic molecules and determination of the redox activity of the hybrid organic/inorganic compositions. Methods: spectrophotometry, fluorescence spectroscopy and fluorescence excitation spectroscopy; time-resolved fluorescence spectroscopy, transmission electron microscopy, scanning electron microscopy, and dynamic light scattering. Theoretical and practical results, scientific novelty: for the first time, the formation of an acridine orange fluorescence excimer was revealed at excitation of acridine orange adsorbed in a near-surface layer of nanoparticles. An effective nonradiative electron excitation energy transfer in nanoparticles – photosensitizer complexes in aqueous solutions and calcium carbonate mesoporous microcontainers under UV and X-ray excitation was shown. Generation of reactive oxygen species in aqueous solutions of calcium carbonate mesoporous microcontainers with nanoparticles – photosensitizer complexes under UV irradiation was shown. For the first time the ability of vanadate nanoparticles to destroy hydroxyl radicals formed during water radiolysis upon X-ray irradiation of aqueous solutions was determined. Practical significance: the fundamental knowledge about the interaction between organic molecules and inorganic nanoparticles obtained in the thesis can be used for the development of the new hybrid organo/inorganic compositions for application in theranostics. The results open wide prospects for using the complexes in such a modern biomedical field as X-ray-stimulated photodynamic therapy to increase significantly the therapy effectiveness. Scope of application: at carrying out the research work in the Department of Nanostructured Materials of the Institute for scintillation materials of the National Academy of Sciences of Ukraine and in joint work with colleagues from the S.P. Grigoriev Institute of Medical Radiology of National Academy of Medical Sciences of Ukraine.