School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, 150001, China.
Tianjin Key Laboratory for Photoelectric Materials and Devices, School of Materials Science & Engineering, Tianjin University of Technology, Tianjin, 300384, China.
Org Biomol Chem. 2020 Jul 15;18(27):5238-5244. doi: 10.1039/d0ob00507j.
The mercury ion (Hg2+), one of the most notorious heavy metal ions, not only causes environmental pollution, but also endangers human health. There is evidence that Hg2+ tends to accumulate in the mitochondria and to induce apoptosis. However, mitochondria-targeted near-infrared (NIR) fluorescent probes with large Stokes shifts are still scarcely described for the specific detection of Hg2+. In this work, a novel near-infrared fluorescent probe JRQNS with a large Stokes shift (78 nm) was reported, and applied for sensitive and specific detection of Hg2+ in mitochondria by incorporating an additional amine group with fused rings to rhodamine dyes to enhance the electron donating ability of amine groups. As expected, the probe exhibited high selectivity and sensitivity to Hg2+ with a detection limit as low as 1.5 nM and fast response times (3 min), revealing that JRQNS could be used as a practical probe for quantitative detection of Hg2+ in real-time. Importantly, JRQNS can be used as an efficient organelle-targeting probe for imaging Hg2+ in the mitochondria of living cells, and thus detect Hg2+ in real-time there. The application of the probe for its selective localization in mitochondria along with the nanomolar level of limit of detection to Hg2+ ions provided a potential tool for studying the cytotoxic mechanisms of Hg2+.
汞离子（Hg2+）是最臭名昭著的重金属离子之一，不仅造成环境污染，还危害人类健康。有证据表明，Hg2+ 容易在线粒体中积累，并诱导细胞凋亡。然而，用于特异性检测 Hg2+的具有大斯托克斯位移的线粒体靶向近红外（NIR）荧光探针仍然很少见。在这项工作中，报道了一种新型的具有大斯托克斯位移（78nm）的近红外荧光探针 JRQNS，通过将额外的胺基与融合环引入到罗丹明染料中，增强了胺基的供电子能力，从而对 Hg2+具有高选择性和灵敏度。探针的检测限低至 1.5 nM，响应时间快（3 分钟），预期可用于线粒体中 Hg2+的灵敏和特异性检测。重要的是，JRQNS 可以用作活细胞线粒体中 Hg2+成像的有效细胞器靶向探针，从而实时检测 Hg2+。该探针选择性定位于线粒体，检测限低至纳摩尔级，为研究 Hg2+的细胞毒性机制提供了一种潜在的工具。
