Confining Thiolysis of Dinitrophenyl Ether to a Luminescent Metal-Organic Framework with a Large Stokes Shift for Highly Efficient Detection of Hydrogen Sulfide in Rat Brain.

Hydrogen sulfide (HS) is a gaseous signaling molecule that regulates various physiological and pathological processes in the central nervous system. It is vital to develop an effective method to detect HS in vivo to elucidate its critical role. However, current fluorescent probes for accurate quantification of HS still face big challenges due to complicated fabrication, small Stokes shift, unsatisfactory selectivity, and especially delayed response time. Herein, based on simple postsynthetic modification, we present an innovative strategy by confining HS-triggered thiolysis of dinitrophenyl (DNP) ether within a luminescent metal-organic framework (MOF) to address those issues. Due to the cleavage of the DNP moiety by HS, the nanoprobe gives rise to a remarkable fluorescence turn-on signal with a large Stokes shift of 190 nm and also provides high selectivity to HS against various interferents including competing biothiols. In particular, by virtue of the unique structural property of the MOF, it exhibits an ultrafast sensing ability for HS (only 5 s). Moreover, the fluorescence enhancement efficiency displays a good linear correlation with HS concentration in the range of 0-160 μM with a detection limit of 0.29 μM. Importantly, these superior sensing performances enable the nanoprobe to measure the basal value and monitor the change of HS level in the rat brain.