Novel Multifunctional Samarium–Organic Framework for Fluorescence Sensing of Ag(+), MnO(4)(–), and Cimetidine and Electrochemical Sensing of o-Nitrophenol in Aqueous Solutions

[Image: see text] A novel Sm-metal–organic framework (MOF) sensor with the molecular formula Sm(8)(HDBA)(6)·H(2)O has been prepared based on a penta-carboxyl organic ligand (H(5)DBA = 3,5-di(2′,4′-dicarboxylphenyl)benzoic acid) and samarium nitrate under solvothermal conditions. Sm-MOF is characterized by single-crystal X-ray diffraction analysis, elemental analysis, thermogravimetric analysis, and powder X-ray diffraction analysis. Structural analysis shows that the dimer metal units are alternately connected to form a one-dimensional chain, and this chain is connected by the bridging carboxyl oxygen of the ligand H(5)DBA to form a two-dimensional double-layer plane, which then expands into a three-dimensional microporous framework. Fluorescence detection studies show that Sm-MOF can detect Ag(+) ions, MnO(4)(–) anions, and cimetidine tablets with high sensitivity and selectivity and can also be used to electrochemically detect o-nitrophenol in water. High-sensitivity detection capability of the Sm-MOF can enrich the application of samarium complexes in multifunctional sensors.