A novel and stable fluorescent probe for tracking Hg²⁺ with large Stokes shift and its application in cell imaging

Giving the fact that mercury ions (Hg²⁺) is highly toxic, migratory and bioaccumulative and even very small amounts of mercury can cause serious damage to health, resulting in many diseases, such as abdominal pain, renal failure, nervous system damage. The content of mercury in drinking water quality standard of our country has been strictly limited. Therefore, it is of good research interest to develop a stable fluorescent probe capable of detecting the presence of mercury in biological cells. In this study, a novel fluorescent probe based on isophoronitriles scaffold, DNC-Hg, was designed and synthesized for monitoring mercury ion in living HeLa cells. The good properties of the probe may be attributed to the unique strong electron-absorbing group in the structural design, the good conjugation effect, and the mature Hg²⁺ recognition site. The probe exhibited good selectivity and stability, large Stokes shift(174 nm) and low cytotoxicity. Furthermore, this stable probe DNC-Hg could be used for cellular imaging.