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A novel 3D Eu(iii) metal-organic framework (Eu-MOF-1) formulated as [Eu(L)(H2O)(DMA)] (L = 2-(2-nitro-4-carboxylphenyl)terephthalic acid) has been successfully synthesized under solvothermal conditions and characterized by structural analyses. Eu-MOF-1 displays a new 3D framework containing EuIII ions, ligand L, and coordinated DMA molecules and water molecules. The fluorescence investigations indicate that Eu-MOF-1 emits bright red luminescence, and shows relatively high water stability and outstanding chemical stability under a relatively wide range of pH conditions. It is noteworthy that Eu-MOF-1 can quantitatively detect p-aminophenol (PAP) which is a metabolite of phenylamine in human urine. More significantly, Eu-MOF-1 is the first reported multi-responsive luminescent sensor for detecting the biomarker PAP, and MnVII and CrVI anions with high selectivity, sensitivity, recyclability and relatively low detection limits in aqueous solutions. Furthermore, the possible sensing mechanisms of Eu-MOF-1 for selective sensing have also been explored in detail. Eu-MOF-1 could be an ideal candidate as a multi-responsive luminescent sensor in biological and environmental areas.

Metal-organic frameworks (MOFs) have emerged as a promising electrode material for supercapacitors owing to their high porosity and a regular porous structure, however, the capacitance performance and/or ion conduction rate performance of most MOFs with poor electrical conductivity are greatly hindered. To increase the bulk electrical conductivity and the efficiency of MOFs, an effective method was proposed by interweaving organic conductive polymer polyaniline (PANI) and MOF crystals (ZIF-67) grown in situ. As a result, the highly conductive PANI that interlink the MOF particles (denoted as ZIF-67@PANI) increase the electron transfer between MOF particles while the effective porosity of the MOF is maintained, which greatly improves the electrical conductivity and capacitance of MOFs. Electrochemical studies indicates that the ZIF-67@PANI exhibits ultrahigh specific capacity of 1123.65 C g−1 at a current density of 1 A g−1 in a three-electrode system, superior rate capability (648.9 C g−1 at 10 A g−1 current density) and excellent cycling stability (92.3% capacity retention after 9000 cycles). Furthermore, a symmetrical supercapacitor device based on ZIF-67@PANI network exhibits ultrahigh energy density of 71.1 W h kg−1 at a power density of 504.72 W kg−1 at 1 A g−1 current density. The capacitance performance of ZIF-67@PANI- 2 we report here is the best among the supercapacitor materials formed by MOFs and conductive polymers up to date, confirming the importance of hybrid materials on the nanoscale and the significance of in situ synthetic chemistry. PANI-coated in-situ growth of ZIF-67 can greatly improve the conductivity of ZIF-67 and exhibit excellent capacitor performance. Image 1 • The ZIF-67@PANI hybrids are prepared and exhibit excellent capacitor behaviors. • The ZIF-67@PANI- 2 capacitor shows specific capacity of 2497 F g−1 at 1 A g−1 in a 3-electrode system. • The capacitance of the capacitor remains 92.3% at 5 A g−1 after 9000 cycles. [ABSTRACT FROM AUTHOR]

• A new metal–organic framework (Eu-MOF- 1) based on Eu(III) and carboxylate linker was synthesized. • Eu-MOF- 1 exhibits an unusual 3D framework based on 1D metal-carboxylate chains. • Eu-MOF- 1 was used as multi-responsive fluorescence sensor for the detection of biomarker 1-naphthol. • Eu-MOF- 1 as a sensor shows high selectivity, sensitivity and remarkable recyclability. A new three-dimensional Eu(III) metal–organic framework Eu(III)-MOF- 1 formulated as [Eu 3 (BDC) 4.5 (H 2 O)(DMF) 2 (H 2 BDC = 1,4-benzenedicarboxylic acid), has been successfully synthesized by solvothermal methods and characterized by structural analyses and luminescence studies. Crystallographic studies reveal that the Eu-MOF- 1 exhibits an unusual 3D framework based on 1D metal-carboxylate chains. Significantly, the luminescence explorations demonstrate that the Eu-MOF- 1 is the first multi-responsive fluorescence sensor for sensing biomarker 1-naphthol (1-N) of carbaryl exposure, Fe3+ ions and MnO 4 − ions with high sensitivity, selectivity and excellent recyclability through luminescence quenching. Moreover, the possible mechanisms of selective detection have been investigated in detail. This material could be a promising luminescent sensor for practical applications. [ABSTRACT FROM AUTHOR]