Construction of cationic meso -thiazolium-BODIPY AIE fluorescent probes for viscosity imaging in dual organelles.

Two new cationic meso -thiazolium-BODIPY-based water-soluble and red-shifted fluorescent probes were constructed for the first time. They can monitor cellular viscosity in dual organelles and show aggregation-induced emission (AIE), which is ascribed to the efficient restricted rotation of meso -thiazolium in viscous or hindered systems. Probe 3 with an N -benzyl group shows better AIE as compared to probe 2 with an N -methyl group.