Fluorescent norbornene for sequential detection of mercury and biothiols

A pyrene functionalized norbornene (1) and its homopolymer (P1), which was obtained by the ring opening metathesis polymerization (ROMP) method, have been designed and synthesized. Both 1 and P1 exhibit fluorescence ratiometric sensing of Hg2+ ions in Tris-HCl buffer solution. In addition, the in situ obtained Hg(II) complexes 1-Hg2+ and P1–Hg2+ can sequentially detect biothiols, including cysteine (Cys), homocysteine (Hcy) and glutathione (GSH) via restoration their original fluorescence. In addition, probe 1 has been successfully used for detection of Hg2+ and Cys in living cells. [Display omitted] •Fluorescence polynorbornene-based sensor was prepared.•Both the monomer and polymer probes show ratiometric sensing of Hg(II).•The in situ Hg(II) complexes can recognize thiol-containing amino acids.•Probe is used for fluorescence imaging of intracellular Hg2+ and Cys.