Surface and structure characterization of YVO4-cucurbit[n]uril multifunctional nanoscale platforms

• Grant number: 19/24955-6
• Support type: Scholarships abroad - Research Internship - Scientific Initiation
• Effective date (Start): January 06, 2020
• Effective date (End): March 05, 2020
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal researcher: Paulo Cesar de Sousa Filho
• Grantee: Giulia Rinaldi
• Supervisor abroad: Richard Ian Walton
• Home Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Research place: University of Warwick, England
• Associated to the scholarship: 18/13586-7 - Interactions between YVO4 and cucurbit[n]uryls and insertion of photosensitizing molecules with potential application in photodynamic therapy, BP.IC

Abstract

The development of multifunctional luminescent platforms for photodynamic therapy (PDT) has provided highly interesting candidates for theranostic applications, combining luminescent sensing for diagnosis and light emission for stimulation of photoactive molecules. In this sense, the functionalization of nanostructured lanthanide-doped yttrium vanadate systems (YVO4:Ln3+) can afford new multifunctional systems for PDT because of their promising luminescent properties for optical nanotermometry, and their ability to convert low-damage near infrared (NIR) excitation into visible light. The use of luminescent nanoparticles such as YVO4:Ln3+ (Ln=Eu3+, Yb3+/Er3+) in PDT can therefore help to precisely monitor the temperature with high spatial resolution, leading to the improvement of this type of treatment by accurate control of the local temperature. Hence, we used cucurbit[n]rils (CB[n]) to functionalize the surface of YVO4:Ln3+ particles, since these macrocycles can act as a bridge between the surface of the YVO4 particles and the photoactive dye molecules (e.g. methylene blue, rose Bengal), enabling to combine optical nanothermometry with photodynamic activity. Therefore, this project to accurate characterize YVO4:Ln3+-CB[n] systems in order to understand the structure and surface state of the particles after the modification with the macrocycles and with dyes. We intend to apply small angle X-ray scattering (SAXS), mass spectrometry-coupled thermogravimetry, X-ray photoelectron spectroscopy (XPS) and in situ thermodiffraction to describe the how the organic moieties impact on the surface of the vanadate phase and to detail the chemical state of the active surface of the nanoparticles. (AU)