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

Two-photon probes for biothiols are developed based on arylsulfonyl azides for the first time. Thus, 6-(dimethylamino)naphthalene-2-sulfonyi 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. (C) 2013 Elsevier Ltd. All rights reserved.