A steric control specific probe for visualizing drug induced fluctuations of enzymatic H2S generation in living cells

Hydrogen sulfide (H2S) is an important gas transmitter in living system, and is of great significance in many pathological and physiological processes. It is an attractive challenge to specific detect H2S due to its lower level in cell plasma compared to other three mercaptan compounds (cysteine, homocysteine, and glutathione). The hydroxylated dye DCI-Br, with ortho-site substituted by bromine atoms, exhibited highly activated near infrared fluorescence at pH 7.4, and was selected for constructing the "recognition group hidden" probe DCI-Br-NBD. Owing to the spatial protection effect, the probe showed specific response to H2S over three large volume biothiols, with good linear detection range of 0-50 mu M and detection limit of 0.4 mu M. Moreover, the probe has been successfully applied for visualizing exogenous H2S, and fluctuation process of H2S enzymatic generation caused by enzyme activator and inhibitor. The present strategy of adjusting the probe structure by steric hindrance, may provide guidance for the highly selective recognition of specific analyte in complex systems.