Ferric ions (Fe³⁺) play an important role in various biological and chemical processes in living organisms, natural environments, and industry. To understand these roles, a fast and accurate sensor for the selective detection and quantification of Fe³⁺ is highly desirable. Herein, we report the development and assessment of a luminescent europium metal–organic framework (MOF, with specific acronym EuMTA, named for the ligand used in the synthesis: 2-methoxyterephthalic acid)─polymer composite material. Immobilizing EuMTA within a cross-linked poly(2-hydroxyethyl methacrylate) (PHEMA) matrix resulted in a significant enhancement in the ligand-Eu antenna effect, as well as an increase in the Fe³⁺ sensing range (detection of Fe³⁺ at concentrations between 2 and 120 ppm) compared to native EuMTA powder (0.16–4 ppm). The PHEMA matrix also functioned to protect the embedded MOF, improving the stability of the sensor under acidic conditions, while enhancing Fe³⁺ ion selectivity compared to a EuMTA powder suspension. The MOF-composite sensor exhibited excellent luminescence intensity, stability over prolonged storage (21 days), and reusability. Furthermore, the application of the MOF-composite sensor for mineral processing was successfully demonstrated by monitoring Fe³⁺ concentrations using a simulated mineral leaching model.

中文翻译：

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具有增强发光和选择性铁离子传感功能的铕金属-有机骨架聚合物复合材料

三价铁离子 (Fe ³⁺ ) 在生物体、自然环境和工业的各种生物和化学过程中发挥着重要作用。为了了解这些作用，非常需要一种快速、准确的传感器来选择性检测和定量 Fe ³⁺ 。在此，我们报告了发光铕金属有机骨架（MOF，具体缩写为EuMTA，以合成中使用的配体命名：2-甲氧基对苯二甲酸）─聚合物复合材料的开发和评估。将 EuMTA 固定在交联聚（甲基丙烯酸 2-羟乙酯）(PHEMA) 基质中导致配体-Eu 天线效应显着增强，以及 Fe ³⁺传感范围的^增加（在与天然 EuMTA 粉末 (0.16–4 ppm) 相比，浓度在 2 至 120 ppm 之间。 PHEMA 基质还起到保护嵌入的 MOF 的作用，提高传感器在酸性条件下的稳定性，同时与 EuMTA 粉末悬浮液相比增强 Fe ³⁺离子选择性。 MOF 复合传感器表现出优异的发光强度、长期储存（21 天）的稳定性和可重复使用性。此外，通过使用模拟矿物浸出模型监测 Fe ³⁺浓度，成功证明了 MOF 复合传感器在矿物加工中的应用。