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A colorimetric and ratiometric fluorescent probe for selective detection and cellular imaging of glutathione

Author:
Xu, Chang, Li, Hongda, Yin, Bingzhu
Source:
Biosensors & bioelectronics 2015 v.72 pp. 275-281
ISSN:
0956-5663
Subject:
absorption, aldehydes, biosensors, cations, colorimetry, cysteine, fluorescence, fluorescent dyes, glutathione, homocysteine, image analysis, permeability
Abstract:
A new colorimetric and ratiometric fluorescent probe 1 based on a chlorinated coumarinyl aldehyde was developed for selective detection and cellular imaging of glutathione (GSH) over cysteine (Cys) and homocysteine (Hcy). Probe 1 exhibits a dramatic colorimetric and ratiometric fluorescence responses toward biothiols Cys, Hcy and GSH with high selectivity over other amino acids. Cys (or Hcy) induces a tandem SNAr-rearrangement reaction to form the corresponding amino-coumarins (2a or 2b), which result in about 75nm and 35nm blue-shifts in absorption and emission, respectively. By comparison, the thio-coumarin (3′) derived from the SNAr reaction with GSH, which does not occur rearrangement because of steric hindrance, undergoes an intramolecular aldimine condensation lead to a cyclic iminium cation (3) with 47nm and 39nm red-shifts in absorption and emission, respectively. The significantly difference of photophysical properties enable excellent selectivity towards GSH over Cys and Hcy. Further application to cellular imaging indicates that the probe has appreciable cell permeability and is highly responsive to the changes of GSH level. As a result, it is applicable to monitor GSH level in living cells.
Agid:
5534822