2,6-pyridine dicarboxylic acid (DPA) is an exceptional biomarker of notorious anthrax spores. Therefore, the rapid, sensitive, and selective quantitative detection of DPA is extremely significant and urgent. This paper reports a Zn(II) metal–organic framework with the formula of {[Zn₆(NDA)₆(DPBT)₃] 2H₂O·3DMF}_n (MOF-1), which consists of 2,6-naphthalenedicarboxylic acid (2,6-NDA), 4,7-di(4-pyridyl)-2,1,3-benzothiadiazole (DPBT), and Zn(II) ions. Structural analysis indicated that MOF-1 is a three-dimensional (3D) network which crystallized in the monoclinic system with the C2/c space group, revealing high pH, solvent, and thermal stability. Luminescence sensing studies demonstrated that MOF-1 had the potential to be a highly selective, sensitive, and recyclable fluorescence sensor for the identification of DPA. Furthermore, fluorescent test paper was made to detect DPA promptly with color changes. The enhancement mechanism was established by the hydrogen-bonding interaction and photoinduced electron transfer transition between MOF-1 and DPA molecules.

Two new luminescent metal-organic frameworks (MOFs), namely [Cd₄(TFBA)₃(H₂O)₄]_n (CdMOF-1) and [Cd(TFBA) (bipy)]_n (CdMOF-2) (H₃TFBA = tris(3′-F-4′-carboxybiphenyl)amine, 4,4′-bipy = 4,4’-bipyridine), have been prepared and successfully constructed via solvothermal conditions. Single-crystal structure analysis reveals that CdMOF-1 are two-dimensional network containing [Cd₄O₂₆] units. CdMOF-2 shows a non-interpenetration 3D microporous structure with a hexagon pore of 24.6 × 25.9 Å. Notably, CdMOF-2 exhibits turn off fluorescence behavior towards picric acid (TNP) and 4-Nitrophenol (PNP) with a limit of detection (LOD) value of 9.2 × 10⁻⁶ M and 1.81 × 10⁻⁵ M, respectively. Furthermore, CdMOF-2 shows obvious turn-on luminescence responses toward acetylacetone (Acac) with luminescence red-shift and a detection limit of 19.40 ppm. Additionally, the possible quenching or enhancing mechanism during the sensing process were evaluated by PXRD, UV-vis, and luminescence decay lifetime.