@misc{10481/54892,
year = {2015},
url = {https://pubs.acs.org/doi/10.1021/acs.jpca.5b07898},
url = {http://hdl.handle.net/10481/54892},
abstract = {Dyes with near-red emission are of great interest because of their undoubted advantages for use as probes in living cells. In-depth knowledge of their photophysics is essential for employment of such dyes. In this article, the photophysical behavior of a new siliconsubstituted xanthene, 7-hydroxy-5,5-dimethyl-10-(o-tolyl)dibenzo[b,e]silin-3(5H)-one (2-Me TM), was explored using absorption, steady-state, and time-resolved fluorescence. First, the near-neutral pH, ground state acidity constant of the dye, pK*N-A, was determined by both absorbance and steady-state fluorescence methods in the presence of very low buffer concentrations. Next, we determined whether the addition of phosphate buffer promoted the excited-state proton exchange reaction between the neutral and anion form of 2-Me TM in aqueous solutions at near-neutral pH. For this analysis, both the steady-state fluorescence method and time-resolved emission spectroscopy (TRES) were employed. The TRES experiments demonstrated a remarkably favored conversion of the neutral form to the anion form. Then, fluorescence decay traces recorded as a function of buffer concentration and pH were globally analyzed to determine the values of the excited-state rate constants. The revealed kinetic parameters were consistent with the TRES results, exhibiting a higher rate constant for deprotonation than for protonation, which implies an unusual low value of the excited-state acidity constant pK*N-A and therefore an enhanced photoacid behavior of the neutral form. Finally, we determined whether 2-Me TM could be used as a sensor inside live cells by measuring the intensity profile of the probe in different cellular compartments of HeLa 229 cells.},
organization = {This research was funded by MINECO (project CTQ2014-56370-R), and MINECO (project CTQ2014-53598).},
publisher = {American Chemical Society},
title = {Photophysics of a Live-Cell-Marker, Red Silicon-Substituted Xanthene Dye},
doi = {10.1021/acs.jpca.5b07898},
author = {Crovetto González, Luis and Orte Gutiérrez, Ángel and Paredes, José M. and Resa, Sandra and Valverde Pozo, Javier and Castello, Fabio and Miguel, Delia and Cuerva, Juan M. and Talavera Rodríguez, Eva María and Álvarez Pez, José María},
}