Building Rhodamine-BODIPY fluorescent platform using Click reaction: Naked-eye visible and multi-channel chemodosimeter for detection of Fe3+ and Hg2+

A novel ratiometric fluorescent probe RhB-BODIPY-OH based on Rhodamine and boron dipyrromethene (BODIPY) platform for sensing Fe 3+ and Hg 2+ ions was synthesized by Click reaction. RhB-BODIPY-OH dendron was a hybrid fluorescent probe with reaction-based as well as lock/key-based detection sites, which contains four recognition positions including Schiff base C N functionality, triazole–triazole linker and the spirocyclic ring of the Rhodamine unit. Naked eye detection was realized with the obvious color change. In addition, low detection limit was calculated from titration results with the value were 7.74 × 10 −8  M for RhB-BODIPY-OH/Hg 2+ as well as 3.91 × 10 −7  M for RhB-BODIPY-OH/Fe 3+ , separately. The probe is highly sensitive, the detection time is less than 2s. On top of that, living cell imaging experiment was carried out, which demonstrated that RhB-BODIPY-OH is a good bioimaging agent in living cells. Eventually, amino-group-functionalized silica fluorescent nanoparticles (FNPs) encapsulating the RhB-BODIPY-OH dyes were prepared and characterized by transmission electron microscopy.