A pyrrole-tricyanofuran-based probe for the detection of bisulfite and viscosity in lysosomes of living cells and zebrafish

A novel AIE active bifunctional probe for detecting bisulfite (HSO3−) and viscosity synchronously was developed based on pyrrole-tricyanofuran skeleton. This probe exhibited aggregation-induced emission behavior in almost pure aqueous media, and responded to HSO3− with a “turn-off” signal and viscosity changes with a “turn-on” signal in semi-aqueous solutions, respectively. The response mechanism of the probe associated with HSO3−-involving CC breakage was demonstrated via ESI-MS, 1H NMR analysis, and density functional theory calculations. Furthermore, the probe has been applied to imaging endogenous HSO3− and viscosity changes in the lysosomes of C6 cells and zebrafish.