A fluorescent probe based on an enhanced ICT effect for Hg detection and cell imaging.

The mercury ion (Hg) has hindered society to some extent due to its high biological toxicity, and a rapid method for Hg detection is urgently needed. In the present work, two fluorescent probes, YF-Hg and YF-Cl-Hg, were developed. YF-Cl-Hg was produced by introducing an electron-withdrawing substituent (-Cl) into the structure of YF-Hg. The probe YF-Cl-Hg possesses a larger Stokes shift and a more pronounced UV-vis absorption redshift compared to YF-Hg in a pH = 7.4 environment. The reasons for the superior spectral performance of YF-Cl-Hg over YF-Hg were explored by density functional theory (DFT) calculations and UV-vis absorption spectroscopy. Furthermore, the good biocompatibility suggests that YF-Cl-Hg possesses the potential to be a tool for Hg detection in cells.