Thiol-selective sensor based on intramolecular energy transfer between a bichromophoric system

A pyrene and [Ru(bpy)3]2+ bichromophoric sensor (1) with efficient intramolecular energy transfer was designed for highly selective detection of thiol-containing biomolecules, such as glutathione (GSH). The sensor shows increased pyrene emission and reduced 3MLCT emission upon interaction with thiols. The interaction mechanism might be due to the cleavage of the disulfide bond connecting two chromophores with the addition of thiols, thus terminating the intramolecular energy transfer in 1. A linear relationship was found between the intensity of the pyrene emission at 395 nm and the concentration of GSH ranging from (0–240 μM). Sensor 1 also shows high selectivity toward GSH than other thiol-free analytes.