A novel fluorescent probe CN3, containing 1,8‐naphthalimide and picolinate units, was synthesized, and its structure was characterized by ¹H nuclear magnetic resonance spectroscopy (H NMR), ¹³C nuclear magnetic resonance spectroscopy (C NMR), and mass spectroscopy techniques. The detection property of CN3 toward copper ions (Cu²⁺) has been investigated in ethanol–HEPES buffer (v/v = 1/1, pH = 7.40) solution by UV–Vis absorption and fluorescence emission spectra. The results showed that CN3 had a highly selective and sensitive fluorescence quenching response to Cu²⁺, which was attributed to the generation of weak fluorescent N‐ethyl‐4‐hydroxyphenyl‐1,8‐ naphthalimide (compound 2) in polar ethanol–HEPES buffer (v/v = 1/1, pH = 7.40) via selective hydrolysis reaction. The detection of CN3 for Cu²⁺ was not influenced in the presence of other competing metal ions, and the limit of detection was as low as 50.0 nM. Therefore, the color of CN3 changed from colorless to yellowish when the Cu²⁺ was added. Furthermore, the fluorescent probe CN3 was utilized to detect Cu²⁺ in real water samples with fine performance.

中文翻译：

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一种基于萘二甲酰亚胺的高灵敏度荧光探针，可通过选择性水解反应检测Cu2 +及其在实际样品中的应用

合成了一种新型荧光探针CN3，它包含1,8-萘二甲酰亚胺和吡啶甲酸单元，并通过¹ H核磁共振波谱（H NMR），¹³ C核磁共振波谱（C NMR）和质谱对结构进行了表征技术。通过UV-Vis吸收和荧光发射光谱研究了乙醇-HEPES缓冲液（v / v = 1/1，pH = 7.40）中CN3对铜离子（Cu ²⁺）的检测特性。结果表明，CN3对Cu ²⁺具有高度选择性和灵敏的荧光猝灭响应。，这归因于极性乙醇-HEPES缓冲液（v / v = 1/1，pH = 7.40）中通过选择性水解反应生成的弱荧光N-乙基-4-羟基苯基-1,8-萘二甲酰亚胺（化合物2） 。在存在其他竞争性金属离子的情况下，CN3对Cu ²⁺的检测不受影响，并且检测限低至50.0 nM。因此，当添加Cu ²⁺时，CN3的颜色从无色变为淡黄色。此外，荧光探针CN3用于检测真实水样中的Cu ²⁺具有良好的性能。