3-hydroxychromone dyes undergo a photo-induced intramolecular proton transfer in the excited state (ESIPT) giving rise to dual emission in the fluorescence spectra, which are attributed to originate from two forms, namely, an excited normal (N*) form and the proton-transferred tautomer (T*) form, respectively. The ratio of the intensities of this dual emission is sensitive to solvent polarity and hydrogen-bonding ability owing to a modulation of the dynamics of the ESIPT reaction.
Towards the application of these dyes as ratiometric sensors of their environment in complex biological systems, photophysics and associated ESIPT dynamics of the 3-hydroxychromones were explored in biomimetic systems such as lipid vesicles, micelles and cyclodextrins which has paved the way to development of novel 3-hydroxychromone and 3-hydroxyflavone dyes for monitoring site-specific probing and imaging of peptide interactions.
Department of Chemistry, West Bengal State University, Calcutta – 700126, India