An ultra-sensitive fluorescent “Turn On” biosensor for glutathione and its application in living cells

In this work, a novel fluorescent biosensor for ultrasensitive and highly selective detection of intracellular GSH was fabricated successfully by coupling the controlled-release of cargo molecules from gated Au nanocages (AuNCs) and the cleavage of S-S bonds in disulfide-containing DNAs by GSH. A detection limit of as low as 4.8 × 10−13 M could be achieved. The results of fluorescence microscopy imaging of GSH in living cells indicate that the fabricated system is an efficient controlled-release biosensor in response to intracellular target molecules and predict its potential use for in situ molecular imaging in living systems.227