ABSTRACT A simple Schiff-base fluorescent probe (L) was synthesised for selective detection of Zn2+ ion in CH3CN/HEPES solution (1/1, 10.0 μM, pH = 7.0). The probe L showed highly fluorescence enhancement towards Zn2+ over other metal ions with obvious fluorescence colour change from faint yellow to blue, which should be attributed to the formation of a 1:2 ligand-metal complex resulting in the inhibition of intramolecular charge transfer (ICT) and the chelation-enhanced fluorescence (CHEF) process. The bonding mechanism was confirmed by UV-vis, fluorescence, HRMS, 1 H NMR experiments and theoretical calculation. Reversibility of the probe in its binding with Zn2+ ion was established in the presence of EDTA. Furthermore, the fluorescence imaging indicated that probe L could be used to effectively identify Zn2+ in living cells. Graphical abstract A novel simple Schiff-base fluorescent probe (L) has been prepared for selective detection of Zn2+ ion in CH3CN/HEPES solution (1/1, 10.0 μM HEPES, pH 7.0). The probe L showed highly fluorescence enhancement to Zn2+ over other metal ions with obvious fluorescence colour change from colourless to yellow, which might be attributed to the formation of a 1:2 ligand-metal complex resulting in the inhibition of intramolecular charge transfer (ICT) and the chelation-enhanced fluorescence (CHEF) process. The bonding mechanism was confirmed by UV-vis, fluorescence, 1H NMR experiment and theoretical calculation. Reversibility of the probe in its binding with Zn2+ ion is established in the presence of EDTA. Furthermore, the fluorescence imaging indicated that probe L could be used to effectively identify Zn2+ in living cells.

中文翻译：

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一种用于锌（II）离子和活细胞生物成像的新型可逆荧光探针

摘要 合成了一种简单的席夫碱荧光探针 (L)，用于选择性检测 CH3CN/HEPES 溶液 (1/1, 10.0 μM, pH = 7.0) 中的 Zn2+ 离子。与其他金属离子相比，探针 L 显示出对 Zn2+ 的高度荧光增强，荧光颜色明显从淡黄色变为蓝色，这应该归因于 1:2 配体-金属络合物的形成导致分子内电荷转移（ICT）的抑制) 和螯合增强荧光 (CHEF) 过程。通过UV-vis、荧光、HRMS、1 H NMR实验和理论计算证实了键合机制。探针与 Zn2+ 离子结合的可逆性是在 EDTA 存在下确定的。此外，荧光成像表明探针 L 可用于有效识别活细胞中的 Zn2+。图形摘要 一种新型的简单 Schiff 碱荧光探针 (L) 已制备用于选择性检测 CH3CN/HEPES 溶液 (1/1, 10.0 μM HEPES, pH 7.0) 中的 Zn2+ 离子。与其他金属离子相比，探针 L 显示出对 Zn2+ 的高度荧光增强，具有明显的荧光颜色从无色变为黄色，这可能是由于形成了 1:2 的配体-金属络合物，从而抑制了分子​​内电荷转移 (ICT)和螯合增强荧光（CHEF）过程。通过UV-vis、荧光、1H NMR实验和理论计算证实了键合机制。探针与 Zn2+ 离子结合的可逆性是在 EDTA 存在下建立的。此外，荧光成像表明探针 L 可用于有效识别活细胞中的 Zn2+。