Lithium is a potent mood stabilizer and has unusual clinical, pharmacological, and biochemical properties. Therefore, it is of great significance to develop fluorescent probes to monitor Li⁺ in living cells visually. The emission wavelength of the reported Li⁺ fluorescent probes was mostly in the short-wave region, which is greatly interfered by the biological background fluorescence and not suitable for biological imaging. In view of the above shortcomings, we constructed a red emitted fluorescent probe by utilizing the spiropyran derivative as fluorophore and integrating the aza-12-crown-4 as the recognition site of Li⁺. Li⁺ induced the isomerization of spiropyran (fluorescent emission) to release oxygen negative ions, which combined with the coordination effect of crown ether to realize the specific fluorescence detection of lithium ion. The system was used for biological imaging in Hela cells and zebrafish. We believe that the current project will provide an effective visualization tool for studying the biological functions of lithium ions.

锂是有效的情绪稳定剂，具有非同寻常的临床，药理和生化特性。因此，开发可视化监测活细胞中Li ^+的荧光探针具有重要意义。报道的Li ⁺荧光探针的发射波长主要在短波区域，这受到生物学背景荧光的极大干扰，不适合生物学成像。鉴于上述缺点，我们利用螺吡喃衍生物作为荧光团并整合了aza-12-crown-4作为Li ⁺的识别位点，构建了红色发射荧光探针。李⁺诱导螺吡喃异构化（荧光发射）释放出氧负离子，再结合冠醚的配位作用，实现了锂离子的特异性荧光检测。该系统用于Hela细胞和斑马鱼的生物成像。我们相信当前的项目将为研究锂离子的生物学功能提供有效的可视化工具。