Development of a Si-rhodamine-based NIR fluorescence probe for highly specific and quick response of Hg2+ and its applications to biological imaging

Mercury is highly toxic to human health and ecological environment. Aiming to realize real-time and efficient detection of Hg2+, a key strategy for constructing the reaction-type fluorescent probes is to expedite their response to the target ion. Herein, we present a novel fast-response and highly specific Si-rhodamine-based near-infrared (NIR) fluorescence probe, AnSiR-R1, for sensing Hg2+ in biological and ecological media. Assembling an electron–deficient anthraquinonyl function to the probe largely improved the detection efficiency via facilitating its desulfurization process. AnSiR-R1 features a specific turn-on NIR response for Hg2+ with a low detection limit of 6.4 nM, a short response time (<10 s), and a strong anti-interference ability. Especially, it can be qualified as a practical probe for visualizing Hg2+ in living cells and zebra fish.