A cancer cell-specific two-photon fluorescent probe for imaging hydrogen sulfide in living cells

Hydrogen sulfide (H2S) could induce the proliferation of cancer cells in a concentration-dependentmanner, and has close relation with the tumor growth. Monitoring the H2S level in real-time is of great important for understanding its roles in the cancer cell proliferation and the diagnosis of the tumor. Herein, a novel cancer cell-specific two-photon fluorescent probe BN-H2S for detecting H2S in cancer cells was designed and synthesized. Biotin was selected as the cancer cell-specific group and the azide group was employed as the response site for H2S. When BN-H2S responded to H2S, a turn-on fluorescence at 544 nm was observed clearly. BN-H2S exhibited high selectivity for H2S over other relative species. Under the guidance of the biotin group, BN-H2S can be successfully used for the two-photon imaging of H2S in cancer cells, while BN-H2S showed relatively weak response for H2S in normal cells. We expect that this design concept can be further developed for selectively detecting other biomolecules in living cancer cells.