Study of the photophysical properties of tetraphenylporphyrins with ligands derived from imidazopyridines and efficiency of photodynamic inactivation

• Grant number: 24/02454-3
• Support Opportunities: Scholarships in Brazil - Master
• Start date: June 01, 2024
• End date: January 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Leonardo de Boni
• Grantee: Carolina Salgado do Nascimento
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 18/11283-7 - Nonlinear photonics: spectroscopy and advanced processing of materials, AP.TEM

Abstract

This work seeks to obtain and analyze the photophysical properties of a group of photosensitizing molecules with potential application in photodynamic and photothermal therapy. To date, there are few studies that quantify the absorption and fluorescence of these molecules, as well as the temporal responses, which leads to the search for determining their decay rates, mainly the intersystem crossing rate, which describes the transfer efficiency. of molecules to the triplet excited state. The study also seeks to determine in an unprecedented way the two-photon absorption cross-section spectrum, aiming to find greater applicability in biological windows of lower photon energy and greater penetrability. Furthermore, in collaboration, the interaction between photosensitizers and biological molecules will be carried out to observe the change in photodynamic processes and thus the applicability in biological environments. Finally, porphyrins will be applied for photodynamic inactivation in cells from two different bacterial lineages, Escherichia coli and Staphylococcus aureus, allowing a comparative analysis of antimicrobial susceptibility to different bacterial structures. All information obtained will be related to the characteristics of each molecule to understand how the structural change will impact its optical properties.