A Novel Near-Infrared Ratiometric Fluorescence Probe for Hg2+ Based on Quinoline-Fused Rhodamine Dye

As one of the most toxic metals, Mercury ions cause serious environmental pollution and threaten the health of living organisms. Hence, we designed and synthesised a new near-infrared (NIR) ratiometric fluorescent probe toward monitoring of Hg2+ based on quinoline-fused rhodamine dye. Owing to the specific spirolactam ring-opening reaction, the probe exhibits a ratiometric fluorescent change after treatment of Hg2+ with increased emission in NIR and significantly reduced emission in visible region. The specific response mechanism and dual-channel fluorescence change allow the probe to have remarkable detection selectivity, fast response and high detection sensitivity. Moreover, with the properties of excellent cell permeability and low cytotoxicity, probe can be applied as detection tool for mercury ions with dual-channel ratiometric fluorescence imaging in living cell.

Automated summary

We designed and synthesized a new near-infrared ratiometric fluorescent probe for monitoring mercury ions based on quinoline-fused rhodamine dye. The probe shows a ratiometric fluorescent change after treatment with mercury ions, with increased emission in the near-infrared region and significantly reduced emission in the visible region. The probe has remarkable detection selectivity, fast response, and high detection sensitivity, and can be applied as a detection tool for mercury ions with dual-channel ratiometric fluorescence imaging in living cells.