A solvatofluorochromic silicon-substituted xanthene dye useful in bioimaging

Abstract

In this work, we have performed an in-depth study of the photophysics and solvatofluorochromism of a red-emitting Si-xanthene dye, an analog of Tokyo Magenta (TM) historically developed by Egawa et al. (Chem. Commun. 2011, 47, 4162–4164). The results show a strong dependency of the emission properties of 2-Me-4-OMe-TM on the polarity of the solvent. For instance, the dye exhibited an increase in its fluorescence lifetime with the decrease in solvent polarity. Therefore, in this work, this spectral behavior has been used as a new approach for determining the intracellular microenvironment polarity through the measurement of its fluorescence lifetime by Fluorescence Lifetime Imaging Microscopy (FLIM). Our experiments confirmed the ability of the dye to detect changes in polarity between different intracellular compartments.