Autor(es): Pereira, Nelson A. M. ; Laranjo, Mafalda ; Casalta-Lopes, João ; Serra, Arménio C. ; Piñeiro, Marta ; Pina, João ; Seixas de Melo, J. Sérgio ; Senge, Mathias O. ; Botelho, M. Filomena ; Martelo, Liliana ; Burrows, Hugh D. ; Pinho e Melo, Teresa M. V. D.
Data: 2017
Identificador Persistente: https://hdl.handle.net/10316/41710
Origem: Estudo Geral - Universidade de Coimbra
Novel near-infrared luminescent compounds based on platinum(II) 4,5,6,7-tetrahydropyrazolo[1,5-a]pyridine-fused chlorins are described. These compounds have high photostability and display light emission, in particular simultaneous fluorescence and phosphorescence emission in solution at room temperature, in the biologically relevant 700-850 nm red and near-infrared (NIR) spectral region, making them excellent materials for biological imaging. The simultaneous presence of fluorescence and phosphorescence emission at room temperature, with the phosphorescence strongly quenched by oxygen whereas fluorescence remains unaffected, allows these compounds to be used as ratiometric oxygen sensors in chemical and biological media. Both steady-state (fluorescence vs phosphorescence intensities) and dynamic (dependence of phosphorescence lifetimes upon oxygen concentration) luminescence approaches can be used. Photocytotoxicity studies against human melanocytic melanoma cells (A375) indicate that these compounds display potential as photosensitizers in photodynamic therapy.
This work was funded by FEDER - Fundo Europeu de Desenvolvimento Regional through the COMPETE 2020 - Operational Programme for Competitiveness and Internationalisation (POCI), and by Portuguese funds through FCT - Fundação para a Ciência e a Tecnologia in the framework of the project POCI-01-0145-FEDER-PTDC/QEQ- MED/0262/2014.), Portuguese Agency for Scientific Research. The Coimbra Chemistry Centre (CQC) is supported by FCT through project no 007630 UID/QUI/00313/2013, co-funded by COMPETE2020-UE. The FCT is also acknowledged for a post-doctoral grant to J. Pina (ref. SFRH/BPD/108469/2015). We acknowledge the UC-NMR facility for obtaining the NMR data (www.nmrccc.uc.pt), and Professor Mário N. Berberan- Santos (Instituto Superior Técnico) for valuable discussions The authors also gratefully acknowledge Perkin-Helmer, Inc. and Intrumentos de Laboratório Científico, Lda (ILC) for providing the EnSpire Multimode Plate Reader and Dr. Hans-Peter Steffens (Perkin-Helmer, Inc) for technical support. MOS acknowledges grant SFI IvP 13/1894.
