A new layer-like metal–organic framework {[Cd₄(NDIC)₄·5DMF·H₂O]DMF}_n (NDIC = 5-(5-norbonene-2,3-dicarboximide) isophthalic acid) was synthesized by solvothermal method. It was used as a parent framework to encapsulate Tb³⁺ cations in Cd-MOF. The obtained composite Tb(3+)@Cd-MOF exhibited excellent luminescence and produced a remarkable quenching effect in the luminescence emission of Tb³⁺ upon the introduction of Cr³⁺. Subsequently, Tb(3+)@Cd-MOF was developed as a highly selective and sensitive probe for detection of Cr³⁺. In particular, the luminescence probe of Cr³⁺ had a low detection limit (7.5 × 10⁻⁸ M), a broad linear range (1 × 10⁻⁷–5 × 10⁻⁶ M). A paper strip coated with Tb(3+)@Cd-MOF was also shown to be highly selective to Cr³⁺ under the irradiation of 254 nm UV light of by the naked eyes. This is the first example for detecting metal ions based on a lanthanide functionalized new metal–organic framework (MOF).

中文翻译：

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一种新型的Tb（iii）功能化层状Cd MOF作为发光探针，用于高选择性地检测Cr ³⁺ †

溶剂热法合成了一种新的层状金属有机骨架{[Cd ₄（NDIC）₄ ·5DMF·H ₂ O] DMF} _n（NDIC = 5-（5-降冰片烯-2,3-二苯甲酰亚胺）间苯二甲酸）方法。它被用作母体框架将Tb ³⁺阳离子封装在Cd-MOF中。引入Cr ³⁺后，所得复合材料Tb（3 +）@ Cd-MOF表现出优异的发光性能，并在Tb ³⁺的发光发射中产生了显着的猝灭效果。随后，开发了Tb（3 +）@ Cd-MOF作为检测Cr ³⁺的高选择性和灵敏探针。尤其是Cr ³⁺发光探针的检出限低（7.5×10^-8 M），较宽的线性范围（1×10 ^-7 –5×10 ^-6 M）。还显示了用Tb（3 +）@ Cd-MOF涂覆的纸条在裸眼在254 nm紫外线的照射下对Cr ³⁺具有高度选择性。这是基于镧系元素官能化的新型金属-有机骨架（MOF）检测金属离子的第一个示例。