Heavy metal ions and antibiotic contamination have become a major environmental concern worldwide. The development of efficient recognition strategies of these pollutants at ultra‐low concentrations in aqueous solutions as well as the elucidation of the intrinsic sensing mechanism are challenging tasks. In this work, unique luminescent Ln‐MOF materials (NIIC‐3‐Ln) were assembled by rational ligand design. Among them, NIIC‐3‐Tb demonstrated highly selective luminescence quenching response toward Hg2+ and sulfadiazine (SDI) at subnanomolar concentrations in less than 7 s. In addition, a Hg2+ sensing mechanism through chelation was proposed on the basis of single‐crystal X‐ray diffraction analysis and Hg2+ adsorption study. The interaction mechanism of NIIC‐3‐Tb with SDI was revealed using a newly developed approach involving a (TD‐)DFT based quantification of the charge transfer of a MOF‐analyte supramolecular complex model in the ground and excited states. Effect of ultrasonic treatment on the surface morphology important for MOF sensing performance was revealed by gas adsorption experiments. The presented results indicate that NIIC‐3‐Ln is not only an advanced sensing material for the efficient detection of Hg2+ and SDI at ultra‐low concentrations, but also opens up a new approach to study the sensing mechanism at the molecular level at ultra‐low concentrations.

中文翻译：

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Ln-MOF 高效 Hg2+ 和磺胺嘧啶传感中的发光猝灭机制的实验和理论阐明


重金属离子和抗生素污染已成为全球主要的环境问题。开发对水溶液中超低浓度污染物的有效识别策略以及阐明其内在传感机制是一项具有挑战性的任务。在这项工作中，通过合理的配体设计组装了独特的发光Ln-MOF材料（NIIC-3-Ln）。其中，NIIC-3-Tb 在不到 7 秒的时间内表现出对亚纳摩尔浓度的 Hg2+ 和磺胺嘧啶 (SDI) 的高度选择性发光猝灭响应。此外，在单晶X射线衍射分析和Hg2+吸附研究的基础上，提出了通过螯合的Hg2+传感机制。使用一种新开发的方法揭示了 NIIC-3-Tb 与 SDI 的相互作用机制，该方法涉及基于 (TD-)DFT 的 MOF 分析物超分子复合物模型在基态和激发态的电荷转移定量。通过气体吸附实验揭示了超声波处理对 MOF 传感性能重要的表面形貌的影响。研究结果表明，NIIC-3-Ln不仅是一种用于高效检测超低浓度Hg2+和SDI的先进传感材料，而且为研究超低浓度Hg2+和SDI的传感机制开辟了新途径。低浓度。