A highly responsive and selective fluorescent probe for imaging physiological hydrogen sulfide.

The discovery of hydrogen sulfide (H2S) as a novel gasotransmitter for cell signaling and other pathophysiological processes has spurred tremendous interest in developing analytical methods for its detection in biological systems. Herein, we report the development of a highly responsive and selective genetically encoded H2S probe, hsGFP, for the detection of H2S both in vitro and in living mammalian cells. hsGFP bestows a combination of favorable properties, including large fluorescence responses, high efficiency in folding and chromophore formation, and excellent sensitivity and selectivity toward H2S. As a genetically encoded probe, hsGFP can be readily and precisely localized to subcellular domains such as mitochondria, cell nuclei, and ion channels. hsGFP was further utilized to image H2S enzymatically produced from l-cysteine in human embryonic kidney (HEK) 293T cells.