"Rare earth ion-doped tantalate nanoparticles with persistent luminescence, energy upconversion and near-infrared emission for applications in nanomedicine"

• Grant number: 22/16692-8
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: June 01, 2023
• End date: November 30, 2023
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Rogéria Rocha Gonçalves
• Grantee: Hayra do Prado Labaki
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 21/08111-2 - Development of rare earth based light converters: luminescent markers, optical sensors, and amplifiers, AP.TEM

Abstract

This project aims at the preparation, characterization and application of nanoparticles with controlled morphology and dimensions for application in nanomedicine. For these purposes, nanoparticles based on Y3TaO7 or YTaO4 (yttrium tantalates) and NaTaO3, doped with rare earth ions (Pr3+, Tm3+ and Nd3+) and alkaline or transition metals (Na+, K+, Cr3+, Ti4+ and Nb5+) will be studied, as well as the Y2O3@YTaO4 and Ta2O5@YTaO4 core-shell systems for the best doping results. The morphological, structural and spectroscopic properties of these materials will be the basis of the study to be carried out, in order to evaluate the performance of the materials and improve them to increase their technological potential as optical markers, scintillators and systems that present persistent luminescence.Since one of the main purposes of this work will be the application in biological systems, for the doping of these materials, lanthanides will be used that present emission in the so-called biological transparency windows in the near infrared region. Luminescence in the visible region will also be studied, aiming at the great emission potential resulting from energy upconversion processes, enabling application as infrared to visible energy converters. Studies on the dependence of luminescent properties on doping will be explored, resulting in different crystalline structures depending on the concentration and nature of the rare earth dopant ion. Furthermore, the investigation of persistent luminescence in these materials, as well as the elucidation of its mechanism, will also be an integral part of this project. The study of luminescence and decay time as a function of temperature is also proposed with a view to applying these systems as nanothermometers.At the same time, a study of radioluminescence and persistent luminescence upon excitation in the X-ray will be explored. The combination of persistent luminescence and radioluminescence of scintillator materials is quite relevant, as it is possible to prolong the time in which photosensitizers are activated by the luminescence of scintillators without the need for additional applications of other doses of radiation.In addition, the evaluation of cell viability and cytotoxicity will be carried out, mainly for the systems that presented the best luminescent performance, as well as in vivo and in vitro studies aiming at the application of the particles as light converters in Theranostic. This project is linked to the Thematic Project "LIGHT CONVERTER MATERIALS BASED ON RARE EARTHS: LUMINESCENT MARKERS, SENSORS AND OPTICAL AMPLIFIERS" (2021/08111-2).