An activatable AIEgen for imaging of endogenous H2S: Reticulation based H2S gas sensor

Novel 2,4-dinitrophenylether functionalized hydroxybenzothiazole derivative (HBT 3) has been synthesized and characterized for selective and rapid detection of H2S in aqueous medium, gas phase and live cells. The H2S induced thiolysis of 2,4-dinitrophenylether leads to morphological transformation in HBT 3 from spherical to reticulate with aggregation induced emission (AIE + ESIPT) at 550 nm (greenish yellow aggregates) as evidenced by optical, DLS, NMR and AFM studies. The HBT 3 can specifically detect H2S with limits of detection as low as 0.45 and 1.22 mu M in CH3CN; 2.9 mu M and 6.8 mu M in 70% HEPES buffer-CH3CN solution. The HBT 3 based solution- and solid- supported point-of-care testing (POCT) kits have been explored for detection of 75-400 ppm H2S gas; 2.4 mu g H2S with fluorescence color change from non-fluorescent to fluorescent yellow. HBT 3 has been successfully utilized for endogenous and exogenous detection of H2S in live L929 cells.