Sensitive and rapid detection of endogenous hydrogen sulfide distributing in different mouse viscera via a two-photon fluorescent probe.

Development of efficient methods for detection of endogenous H2S in living cells and tissues is of considerable significance for better understanding the biological and pathological functions of H2S. Two-photon (TP) fluorescent probes are favorable as powerful molecular tools for studying physiological process due to its non-invasiveness, high spatiotemporal resolution and deep-tissues imaging. Up to date, several TP probes for intracellular H2S imaging have been designed, but real-time imaging of endogenous H2S-related biological processes in tissues is hampered due to low sensitivity, long response time and interference from other biothiols. To address this issue, we herein report a novel two-photon fluorescent probe (TPP-H2S) for highly sensitive and fast monitoring and imaging H2S levels in living cells and tissues. In the presence of H2S, it exhibits obviously improved sensitivity (LOD: 0.12 μM) and fast response time (about 2 min) compared with the reported two-photon H2S probes. With two-photon excitation, TPP-H2S displays high signal-to-noise ratio and sensitivity even no interference in cell growth media. As further application, TPP-H2S is applied for fast imaging of H2S in living cells and different fresh tissues by two-photon confocal microscope. Most importantly we first measured the endogenous H2S level in different viscera by vivisection and found that the distribution of endogenous H2S mostly in brain, liver and lung. The excellent sensing properties of TPP-H2S make it a practically useful tool for further studying biological roles of H2S.