A Highly Selective Turn‐On Fluorescence Sensor for Detecting Hg²⁺ Based on Flavonol and Its Applications in Fluorescence Imaging

Hg 2+ has harmful toxicity to both ecosystems and biological systems, so accurate monitoring of Hg 2+ is essential. Herein, a novel turn‐on fluorescence sensor (HTZ) cooperating flavonol with thiocarbonate group was prepared. It exhibited a wider linear range (0–1 μM) and an ultra‐low detection limit (8.12 nM) in fluorescence measurement of Hg 2+ with high selectivity and excellent anti‐interference property. The corresponding recognition mechanism was investigated and verified by mass spectrometry. Moreover, this proposed probe held the ability of visualizing Hg 2+ in living cells and zebrafish with good biocompatibility and low cytotoxicity. It also exhibited its high accuracy in detecting Hg 2+ in real water samples. All the results proved that the probe was a promising tool that can be used to detect Hg 2+ in complex biological systems and real water samples.