Abstract Calcium is an essential element for living systems and involved in numerous intracellular signaling cascades. In this work, a novel fluorescent probe based on a coumarin and pyrazoline scaffold was designed and synthesized for the detection of Ca2+ by a photoinduced electron transfer (PET) strategy. The probe showed good selectivity for Ca2+ compared to other substances in ethanol with a low detection limit (1.37 × 10−7 M). Meanwhile, following the addition of Ca2+ ions, the probe showed an obvious “turn on” with a rapid response of less than 5 s and 1:1 binding with an association constant of 7.97 × 103 M−1. Furthermore, the fluorescence imaging of the probe was also performed in the presence of Ca2+ in living A549 cells.

中文翻译：

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香豆素基吡唑啉支架荧光测定钙离子及其在活细胞中的应用

摘要 钙是生命系统的必需元素，参与众多细胞内信号级联。在这项工作中，设计并合成了一种基于香豆素和吡唑啉支架的新型荧光探针，用于通过光诱导电子转移 (PET) 策略检测 Ca2+。与乙醇中的其他物质相比，该探针对 Ca2+ 显示出良好的选择性，检测限较低 (1.37 × 10−7 M)。同时，在加入 Ca2+ 离子后，探针显示出明显的“开启”，快速响应小于 5 秒，结合率为 1:1，结合常数为 7.97 × 103 M-1。此外，还在活 A549 细胞中存在 Ca2+ 的情况下进行探针的荧光成像。