The detection of metal ions is of particular importance for monitoring environmental pollution and life metabolic activities. However, it is still a challenge to achieve Fe³⁺ detection with specific sensitivity and rapid response, especially in the presence of chelating agents for Fe³⁺ ions. Herein, a novel fluorescence probe for Fe³⁺, i.e., amide derivative of [1,2,4]triazolo[1,5-a] pyrimidine (TP, Id), was synthesized, featuring specific Fe³⁺ selectivity, rapid quenching (5 seconds), low limit of detection (0.82 μM), good permeability and low cytotoxicity. More importantly, Id can be used to identify and detect Fe³⁺ in the presence of existing strong chelating agents (e.g., EDTA) for Fe³⁺ ions. The results show that the as-synthesized fluorescence probe is particularly suitable as a bioimaging reagent to monitor intracellular Fe³⁺ in living HeLa cells. Furthermore, we proposed the binding mode for Id with Fe³⁺ ions and the light-emitting mechanism through high-resolution mass spectra and density function theory calculations, respectively. An Id-based test paper can be used to rapidly identify Fe³⁺. These results are expected to improve the development of new sensitive and specific fluorescent sensors for Fe³⁺.

金属离子的检测对于监测环境污染和生命代谢活动具有特别重要的意义。然而，实现具有特定灵敏度和快速响应的Fe ³⁺检测仍然是一个挑战，尤其是在存在 Fe ³⁺离子螯合剂的情况下。在此，合成了一种新型的Fe ³⁺荧光探针，即[1,2,4]三唑并[1,5-a]嘧啶(TP, Id )的酰胺衍生物，具有特异性Fe ³⁺选择性、快速淬灭的特点（5 秒）、低检测限（0.82 μM）、良好的渗透性和低细胞毒性。更重要的是，Id可用于识别和检测Fe ³⁺在存在针对 Fe ³⁺离子的强螯合剂（例如 EDTA）的情况下。结果表明，合成的荧光探针特别适合作为生物成像试剂来监测活 HeLa 细胞中的细胞内 Fe ³⁺。此外，我们分别通过高分辨率质谱和密度函数理论计算提出了Id与Fe ³⁺离子的结合模式和发光机制。基于Id的试纸可用于快速识别Fe ³⁺。预计这些结果将改进对 Fe ³⁺的新型灵敏和特异性荧光传感器的开发。