Dual-emission fluorescent probe for discriminative sensing of biothiols

Abstract

• A new dual-emission fluorescent probe ( RED-NBD ) was developed. • RED-NBD has high sensitivity and can discriminate Cys/Hcy from GSH. • Probe RED-NBD can operate under a single wavelength excitation. • RED-NBD can be used for differentiate imaging of Cys/Hcy and GSH in cells. Herein, a dual-emission fluorescent probe ( RED-NBD ) for discriminative detection of cysteine/homocysteine (Cys/Hcy) and glutathione (GSH) was reported. Probe RED-NBD was prepared by conjugating a new red-emissive fluorophore ( RED ) with nitrobenzofurazan moiety ( NBD ). Upon reacting with Cys/Hcy, RED-NBD can be cleaved into fluorophore RED and NBD-Cys/Hcy, which can display distinct red and green fluorescence under a single-wavelength excitation, respectively. While the reaction between RED-NBD with GSH generates the red-emissive NBD and nonfluorescent NBD-SH. Thus, the RED-NBD can differentiate Cys/Hcy from GSH and realize the sensitive detection of these biothiols with low detection limits. Additionally, RED-NBD has also been used for discriminative visualizing of Cys/Hcy and GSH in cells.