Lanthanide Ce(III)/Tb(III) bimetallic coordination polymer as an advanced electrochemiluminescence emitter for epinephrine sensing application

By rationally introducing Ce(III) and Tb(III) into a coordination polymer (CP), a series of lanthanide bimetallic coordination polymers (Tb:Ce-BCPs) has been prepared in this work. Compared with pure Tb-CP and Ce-CP, bimetallic Tb:Ce-BCPs show stronger and more stable ECL intensity, which is mainly attributed to the "dual sensitization effect" combined with the energy transfer from Ce(III) to Tb(III) and the antenna effect from the ligand to the center atoms of Ce(III) and Tb(III). In the meantime, after explore the ECL intensity and morphologies of all these Tb:Ce-BCPs, the results show that the morphologies and ECL intensities of Tb:Ce-BCPs can be adjusted by doping different molar ratios of Ce(III) in Tb:Ce-BCP. Excitingly, Ce(III) can also act as a co-reaction accelerator, effectively promoting S₂O₈^2- to generate more SO₄^•-, thereby enhancing the ECL intensity of Tb:Ce-BCP. That is to say, Ce(III) plays a triple role in Tb:Ce-BCP. Furthermore, the ECL strength of Tb:Ce-BCP decreased by only 1.8% and 3.5%, respectively after the modified electrode was scanned for 800 s and stored for one month. Enlightened by the excellent ECL properties of Tb:Ce-BCP, we modified Tb:Ce-BCP directly on the surface of electrode, and explored its application in electroanalytical chemistry through the detection of epinephrine (EP) and the detection limit is 33 fmol L^-1. Significantly, our ECL sensing strategy promotes the application of lanthanides in ECL sensor and opens vast possibilities for the synthesis of a new generation of ECL emitter in electroanalytical fields.

Novel Enhanced Lanthanide Electrochemiluminescence Luminophores: Ce3+-Doped TbPO4 Facile Synthesis and Detection for Mucin1

Despite the upsurging interest in electrochemiluminescence (ECL) of lanthanides, the research in this field is still in its infancy due to the low intensity. In this work, a series of Ce³⁺-doped terbium orthophosphates (TbPO₄:Ce) in different proportions have been synthesized through the co-precipitation method at room temperature. Meanwhile, through the investigation of morphologies and ECL properties of these TbPO₄:Ce, it is concluded that the ECL intensity reaches the maximum when the molar ratio of Tb/Ce is 9:1 and the material is nanorod-shaped. The ECL intensity of TbPO₄:Ce is significantly improved by doping with Ce³⁺ due to the dual sensitization strategy of the antenna effect from PO₄^3- to Tb³⁺ and the energy transfer from Ce³⁺ to Tb³⁺. Interestingly, doping with Ce³⁺ can not only adjust morphology of TbPO₄:Ce but also improve the ECL intensity. In addition, to verify the application of TbPO₄:Ce, two single mucin1 (MUC1) aptamers are linked together to form a dual MUC1 aptamer chain. Then, a simple and sensitive ECL biosensor is constructed for the detection of MUC1, which can recognize the double amount of MUC1 and quench the ECL signal. As expected, the proposed biosensor shows good stability and acceptable selectivity and achieves sensitive detection of MUC1 with a dynamic range from 1 fg·mL^-1 to 10 ng·mL^-1 and a limit of detection of 0.5 fg·mL^-1. This work may pave a new avenue for the study of direct ECL emission of lanthanides and prove to be ideal for the research of new ECL luminophores in electrochemical analysis.

Self-Assembly of 1D Double-Chain and 3D Diamondoid Networks of Lanthanide Coordination Polymers through In Situ-Generated Ligands: High-Pressure CO2 Adsorption and Photoluminescence Properties

Two new lanthanide-based coordination polymers, [Sm2(bzz)(ben)6(H2O)3]·0.5H2O (1) and [Eu(bbz)(ben)3] (2), were synthesized and characterized. The described products were formed from in situ-generated benzoate (ben) and N'-benzoylbenzohydrazide (bbz) ligands, which were the products of transformation of originally added benzhydrazide (bzz) under hydrothermal conditions. Compound 1 exhibits a one-dimensional (1D) double-chain structure built up from the connection of the central Sm3+ ions with a mixture of bzz and ben ligands. On the other hand, 2 features a 3D network with a 4-connected (66) dia topology constructed from dinuclear [Eu2(ben)6] secondary building units and bbz linkers. High-pressure CO2 sorption studies of activated 1 show that maximum uptake increases to exceptionally high values of 376.7 cm3 g-1 (42.5 wt%) under a pressure of 50 bar at 298 K with good recyclability. Meanwhile, 2 shows a typical red emission in the solid state at room temperature with the decay lifetime of 1.2 ms.