Lanthanide metal-organic frameworks (Ln-MOFs) broaden the optical sensing applications of lanthanide ions due to the antenna effect between organic ligands and metals. However, the sensitization ability of the ligand to metal ions is limited, and maximizing the sensitization of the electrochemiluminescence behavior of Eu is still a challenge for the application of Ln-MOFs. Therefore, under the guidance of the “cascade sensitization mechanism” based on the antenna effect sensitizing the electrochemiluminescence of bimetallic Ln-MOFs, we proposed Eu/Tb-MOFs with high luminescence intensity as a signal probe. According to the antenna effect, the conjugated structure and high extinction coefficient of the benzene ring of 2-amino terephthalic acid (NH-BDC) can enhance the ECL luminescence intensity of Eu/Tb-MOFs. Tb can act as an energy bridge between NH-BDC and Eu, buffering the energy gap. The bimetallic sensitization is formed between Tb and Eu, which can inhibit the reverse internal flow of energy and ensure the high luminous efficiency of Eu. In addition, the nanosphere mixed valence FeO as a co-reactant accelerator promotes the formation of transient free radical SO through the valence change of Fe/Fe. The ECL immunosensor constructed by luminophores Eu/Tb-MOFs and nanosphere FeO provided a new explanation for the ECL self-luminous of Eu/Tb-MOFs.

中文翻译：

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基于镧系双金属MOFs的电化学发光传感器，具有“级联敏化机制”，可灵敏检测CA242

由于有机配体和金属之间的天线效应，稀土金属有机框架（Ln-MOF）拓宽了稀土离子的光学传感应用。然而，配体对金属离子的敏化能力有限，最大化Eu电化学发光行为的敏化仍然是Ln-MOFs应用的一个挑战。因此，在基于天线效应敏化双金属Ln-MOFs电化学发光的“级联敏化机制”的指导下，我们提出了具有高发光强度的Eu/Tb-MOFs作为信号探针。根据天线效应，2-氨基对苯二甲酸（NH-BDC）苯环的共轭结构和高消光系数可以增强Eu/Tb-MOFs的ECL发光强度。 Tb可以充当NH-BDC和Eu之间的能量桥梁，缓冲能隙。 Tb和Eu之间形成双金属敏化，可以抑制能量的反向内部流动，保证Eu的高发光效率。此外，纳米球混合价态FeO作为共反应加速剂，通过Fe/Fe的价态变化促进瞬态自由基SO的形成。由发光体Eu/Tb-MOFs和纳米球Fe3O构建的ECL免疫传感器为Eu/Tb-MOFs的ECL自发光提供了新的解释。