A novel FRET-based ratiometric fluorescent probe for highly sensitive detection of hydrogen sulfideElectronic supplementary information (ESI) available. See DOI: 10.1039/c4ra16578k

A novel FRET-based ratiometric fluorescent probe H 2 S-CR for the quantitative detection of H 2 S was designed and synthesized. It exhibits a response time of 20 min, a considerable fluorescence signal enhancement (15 fold), and an extremely low detection limit (19 nM). It can be successfully applied to imaging H 2 S in living cells. A novel ratiometric and colorimetric probe H 2 S-CR for the quantitative detection of H 2 S was designed and synthesized based on a H 2 S induced Michael addition-cyclization cascade reaction and the FRET modulated fluorescence off-on response.