Two-photon probes based on arylsulfonyl azides: Fluorescence detection and imaging of biothiols

• Arylsulfonyl azide-based two-photon fluorescent probes for biothiols (H2S, GSH, Cys, Hcy) are developed for the first time.
• The probes show turn-on fluorescence response to biothiols through the reduction of arylsulfonyl azides to arylsulfonamides.
• The relative response of the sensing system to typical biothiols is compared at their biological concentrations.
• Fluorescence imaging of the biothiols in mitochondria is demonstrated by one- and two-photon microscopy.

Two-photon probes for biothiols are developed based on arylsulfonyl azides for the first time. Thus, 6-(dimethylamino)naphthalene-2-sulfonyl azide and its triphenylphosphonium derivative undergo a fast reduction with turn-on fluorescence change by typical biothiols such as hydrogen sulfide, glutathione, cysteine, and homocysteine to produce the corresponding sulfonamides that is two-photon excitable. The cationic probe enables the selective imaging of the biothiols in mitochondria by two-photon fluorescence microscopy.

6-(Dimethylamino)naphthalene-2-sulfonyl azide and its triphenylphosphonium derivative show fluorescence turn-on response to biothiols; the cationic probe enables two-photon fluorescence imaging of the biothiols in mitochondria.Figure optionsDownload as PowerPoint slide