Photosensitizer design: Environmental effect on excited state properties and triplet state lifetime.

• Grant number: 22/13192-4
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: June 01, 2023
• End date: May 31, 2027
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Paula Homem-de-Mello
• Grantee: Mateus Martins Zanotto de Toledo
• Host Institution: Centro de Ciências Naturais e Humanas (CCNH). Universidade Federal do ABC (UFABC). Ministério da Educação (Brasil). Santo André , SP, Brazil
• Associated research grant(s): 25/05779-3 - WATOC 2025 - 13th Triennial Congress of the World Association of Theoretical and Computational Chemists, AR.EXT

Abstract

The photodynamic therapy (PDT) is a noninvasive and selective treatment for cancer and otherdiseases. The excitation of a photosensitizer by a laser with a specific wavelength. This excitedphotosensitizer can react with oxygen present in biological systems, generating reactive oxygenspecies (ROS) and triggering cellular damage. To do so, the photosensitizer must undergo anIntersystem Crossing, going from an singlet excited state to a triplet excited state. It's still achallenge to design photosensitizers that absorb in the therapeutic window (600-800nm) speciallywithout heavy metals, which increase the triplet state lifetime, but at the cost of adding darktoxicity. Excited state geometries are really sensitive to the local molecular environment, speciallyin complex systems such as biological medium. This project aims to study and understand howthe xanthene and BODIPY derivatives behave in a biological system using the hybrid QuantumMechanics/Molecular Mechanics (QM/MM) method. As the PDT involves a intersystem crossing,a process between two states with different spins, we will use non-adiabatic dynamics using amachine learning surface hopping algorithm based on the Landau-Zener formula to calculate thetransition rates for the hopping between states.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

PAULA HOMEM-DE-MELLO; ANA CLARA GONZALEZ DE SOUZA; DIÊGO U. MELO; GABRIEL S. MOL; JHONATHAN R. DE SOUZA; LEONARDO M. CARNEIRO; MAÍRA G. NOBREGA; MATEUS ZANOTTO; RAISSA LOHANNA G. Q. CORRÊA; HUEDER P. M. DE OLIVEIRA; et al. DESIGN BIOINSPIRADO DE CORANTES. Química Nova, v. 48, n. 3, 2024-09-06. (18/25576-6, 22/13192-4)

MARINGOLO, VIVIAN; CARVALHO, ALEXANDRE Z.; HOMEM-DE-MELLO, PAULA; ZANOTTO, MATEUS; MARTINS, FERNANDA C. O. L.; MELCHERT, WANESSA R.; ROCHA, DIOGO L.. Spectrophotometric determination of bisphenol A in beverages using multi-dispersion calibration. FOOD CONTROL, v. 168, p. 9-pg., 2024-09-11. (22/13192-4, 18/05559-0)