Due to their important role in biological systems, it is urgent to develop a material that can rapidly and sensitively detect the concentration of Fe 3+ and Al 3+ ions. In this work, a brand-new Cd II -based metal−organic framework [Cd-(BTBD) 2 (AIC)] n (JXUST-18, BTBD = 4,7-bis(1H-1,2,4-triazol-1-yl)-2,1,3-benzothiadiazole and H 2 AIC = 5-aminoisophthalic acid) with a 4-connected sql topology was designed and synthesized. The symmetrical Cd II centers are linked by AIC 2− ligands with μ 3 -η 1 :η 1 :η 1 :η 1 coordination mode to form a [Cd 2 (COO) 2 ] secondary building unit (SBU). The contiguous SBUs are further connected by BTBD ligands to form a twodimensional (2D) layer structure. JXUST-18 can remain stable in aqueous solutions with pH values of 3−12 or in boiling water. Luminescent experiments suggest that JXUST-18 displays more than eightfold fluorescence enhancement in the presence of Fe 3+ and Al 3+ ions, and the detection limits for Fe 3+ and Al 3+ ions are 0.196 and 0.184 μM, respectively. Furthermore, the change in luminescence color is uncomplicatedly distinguishable with the naked eye under ultraviolet light at 365 nm. In addition, a series of devices based on JXUST-18 including fluorescence test strips, lamp beads, and composite films were developed to detect metal ions via visual changes in luminescence color. Significantly, JXUST-18 is a rare MOF-based turn-on fluorescence sensor for the detection of Fe 3+ ions. The theoretical calculation suggests that the complexation of Fe 3+ /Al 3+ ions and the −NH 2 group contributes to fluorescence enhancement.

Two novel lanthanide metal–organic frameworks (MOFs) with the formulas [Tb­(bidc)­(Hbidc)­(H2O)] n (JXUST-20) and {[Tb3(bidc)4(HCOO)­(DMF)]·solvents} n (JXUST-21) were synthesized based on 2,1,3-benzothiadiazole-4,7-dicarboxylic acid (H2BTDC) under solvothermal conditions. Interestingly, benzimidazole-4,7-dicarboxylic acid (H2bidc) was formed in situ using H2BTDC as the starting material. The self-assembly process of the targeted MOFs with different topological structures can be controlled by the solvents and concentration of the reactants. Luminescence experiments show that JXUST-20 and JXUST-21 exhibit strong yellow-green emission. JXUST-20 and JXUST-21 can selectively sense benzaldehyde (BzH) via a luminescence quenching effect with detection limits of 15.3 and 1.44 ppm, respectively. In order to expand the practical application of MOF materials, mixed-matrix membranes (MMMs) have been constructed by mixing targeted MOFs and poly­(methyl methacrylate) in a N,N-dimethylformamide (DMF) solution, which can also be used for BzH vapor sensing. Therefore, the first case of MMMs derived from TbIII MOFs has been developed for the reversible detection of BzH vapor, providing a simple and efficient platform for the future detection of volatile organic compounds.

A novel three-dimensional Eu3+-based metal-organic framework with the formula {[(CH3)2NH2][Eu(BTDI)]∙H2O∙DMF}n (JXUST-25) was prepared by solvothermal method based on Eu3+ and 5,5'-(benzothiadiazole-4,7-diyl)diisophthalic acid (H4BTDI) with benzothiadiazole (BTD) luminescent groups. Due to...

The development of a rapid and selective method for the identification of dipicolinic acid (DPA), a specific biomarker in bacillus anthracis spores, is of great importance for the avoidance of...

A stable metal–organic framework with the formula {[Co(BBZB)(IPA)]·H2O} n (JXUST-23, BBZB = 4,7-bis(1H-benzimidazole-1-yl)-2,1,3-benzothiadiazole and H2IPA = isophthalic acid) was constructed by incorporating Co2+ ions and two conjugated ligands under solvothermal conditions. JXUST-23 takes a dinuclear cluster-based layer structure with a porosity of 2.7%. In this work, JXUST-23 was used to activate peroxymonosulfate (PMS) to degrade rhodamine B (RhB), a difficult-to-degrade pollutant in water. Compared with pure PMS or JXUST-23, the JXUST-23/PMS system displays the best degradation ability of RhB in neutral solution. When the mass ratio of JXUST-23 to PMS was 2:3, 99.72% of RhB (50 ppm) was removed within 60 min, and the reaction rate was 0.1 min–1. Furthermore, free radical quenching experiments show that SO4 •– was the main free radical during the process of RhB degradation. In addition, JXUST-23 exhibits good reusability for the degradation of the organic dye RhB, making it a potential candidate for environmental remediation.