A novel colorimetric and fluorescent probe for simultaneous detection of SO32-/HSO3- and HSO4- by different emission channels and its bioimaging in living cells.

A novel fluorescent probe (E)-3-ethyl-2-(4-hydroxystyryl)-1,1-di-methyl-1H-benzo-[e]indolium iodide (probe EDB) based on benzo[e]indolium was synthesized, which provided the simultaneous detection of SO32-/HSO3- and HSO4- ion with different emission channels. Based on the principle of ion-induced rotation-displaced H-aggregates, when treated with NaHSO4, a fluorescence enhancement at 580nm was observed with the excitation wavelength at 420nm. While, in the advantage of the nucleophilic addition of SO32- to the vinyl group, strong fluorescence was obtained at 455nm when treated with Na2SO3 with the excitation wavelength at 320nm, along with obvious color change by naked eyes. So the probe could be applied to sense SO32-/HSO3- and HSO4- ion via different excited and emission channels simultaneously. The probe was also applicable for fluorescence imagings of bisulfite and hydrosulfate in HeLa cells.