"Yb(III)-Curcumin Complexes: A two-photon excitation strategy for theranostic applications"

• Grant number: 25/23933-0
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: January 01, 2026
• End date: December 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Sergio Antonio Marques de Lima
• Grantee: Alessandra Mara Garbosa Mutti
• Supervisor: Fabio Piccinelli
• Host Institution: Faculdade de Ciências e Tecnologia (FCT). Universidade Estadual Paulista (UNESP). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil
• Institution abroad: Università degli Studi di Verona, Italy
• Associated to the scholarship: 20/13039-6 - NO-donating luminescent bioactive compounds applicable to viral inhibition of COVID-19, BP.PD

Abstract

Luminescent materials based on lanthanide ions have attracted considerable interest in the biomedical field due to their unique optical properties, which enable simultaneous applications in diagnostics and therapy, known as theranostics. In this context, curcumin, a natural molecule with recognized biological activity and excellent light absorption capacity, stands out as a promising ligand for the formation of complexes with metal ions. This project proposes the development of ytterbium(III) complexes with curcumin and curcuminoid derivatives, exploiting the two-photon excitation strategy and near-infrared (NIR) emission, aiming to obtain efficient and biocompatible luminescent systems for cellular imaging and phototherapy. Initially, Yb(III)-curcumin complexes will be synthesized and characterized using spectroscopic techniques (UV-Vis, FTIR, NMR, photoluminescence, and lifetime) to investigate the energy transfer mechanisms between the ligand and the metal. Photophysical studies under biphotonic excitation will be performed to evaluate the efficiency of NIR emission, the photoinduced generation of reactive oxygen species (ROS), and the stability of the systems in biological media. In a later stage, we intend to apply these materials as luminescent probes in two-photon microscopy, enabling tissue imaging with greater penetration depth and minimal phototoxicity. This study aims to understand the fundamental mechanisms of energy transfer in Yb-curcumin complexes and develop multifunctional probes capable of integrating NIR emission diagnostics and photodynamic therapy, contributing to the advancement of new theranostic platforms based on luminescent materials. (AU)