Fiche publication
Date publication
mars 2020
Journal
Physical chemistry chemical physics : PCCP
Auteurs
Membres identifiés du Cancéropôle Est :
Pr MELY Yves
,
Pr DIDIER Pascal
Tous les auteurs :
Didier P, Kuchlyan J, Martinez-Fernandez L, Gosset P, Léonard J, Tor Y, Improta R, Mély Y
Lien Pubmed
Résumé
The thienoguanine nucleobase (thGb) is an isomorphic fluorescent analogue of guanine. In aqueous buffer at neutral pH, thGb exists as a mixture of two ground-state H1 and H3 keto-amino tautomers with distinct absorption and emission spectra and high quantum yield. In this work, we performed the first systematic photophysical characterization of thGb as a function of pH (2 to 12). Steady-state and time-resolved fluorescence spectroscopies, supplemented with theoretical calculations, enabled us to identify three additional thGb forms, resulting from pH-dependent ground-state and excited-state reactions. Moreover, a thorough analysis allowed us to retrieve their individual absorption and emission spectra as well as the equilibrium constants which govern their interconversion. From these data, the complete photoluminescence pathway of thGb in aqueous solution and its dependence as a function of pH was deduced. As the identified forms differ by their spectra and fluorescence lifetime, thGb could be used as a probe for sensing local pH changes under acidic conditions.
Référence
Phys Chem Chem Phys. 2020 Mar 25;:
