Abstract It is imperative to exploit simple and rapid methods for the detection of total iron in foods to ensure food quality and human health. Herein, we construct the MIL-53(Al)-NH2-MPA nanosensor synthesized by post-synthetic modification process for fluorescent detection of total iron in food matrix. The nanosensor emits intense blue fluorescence with excellent stability. The fluorescence can be efficiently quenched by Fe(III) due to the fact that Fe(III) can preferentially bind with O-quinone bands or –NH2 of MIL-53(Al)-NH2-MPA to form strong coordination complex, and that the heteroatoms (N, O and S) in MIL-53(Al)-NH2-MPA can donate lone-pair electrons to Fe(III) to promote the electron transfer. Moreover, the competitive absorption of excitation energy of MIL-53(Al)-NH2-MPA by Fe(III) endows the nanosensor with superior sensitivity. The fluorescent sensor exhibits excellent anti-interference performances toward other metal ions, and reveals a LOD of 0.36 μM with the broad linear range of 0–110 μM for the detection of Fe(III). Satisfactory recoveries of 92.90–112.70% with RSDs of 0.54–2.48% have been achieved in water and food samples, which are well agreement with inductively coupled plasma mass spectrometry (ICP-MS) (P > 0.05), indicating that MIL-53(Al)-NH2-MPA is applicable for detecting total iron in food matrix.

中文翻译：

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用于荧光检测食品基质中总铁的后功能化铝基金属有机框架

摘要 开发简便、快速的食品中总铁检测方法对保证食品质量和人体健康势在必行。在此，我们构建了通过后合成修饰工艺合成的 MIL-53(Al)-NH2-MPA 纳米传感器，用于荧光检测食品基质中的总铁。纳米传感器发出强烈的蓝色荧光，稳定性极佳。由于 Fe(III) 可以优先与 O-醌带或 MIL-53(Al)-NH2-MPA 的 –NH2 结合形成强配位络合物，因此 Fe(III) 可以有效地淬灭荧光，并且MIL-53(Al)-NH2-MPA 中的杂原子（N、O 和 S）可以向 Fe(III) 提供孤对电子以促进电子转移。此外，Fe(III) 对 MIL-53(Al)-NH2-MPA 激发能的竞争吸收使纳米传感器具有优异的灵敏度。该荧光传感器对其他金属离子表现出优异的抗干扰性能，检测 Fe(III) 的 LOD 为 0.36 μM，线性范围为 0-110 μM。在水和食品样品中实现了 92.90–112.70% 的令人满意的回收率，RSD 为 0.54–2.48%，这与电感耦合等离子体质谱 (ICP-MS) 非常吻合 (P > 0.05)，表明 MIL-53( Al)-NH2-MPA 适用于食品基质中总铁的检测。