A luminescent metal-organic framework as a highly sensitive and selective sensor for the detection of iodate

A Zr-based luminescent metal-organic framework, namely, [Zr6(μ3OH)4(μ3O)4(OH)4(BITD)2(H2O)4]·(DMF)6(H2O)20 (Zr-BITD), was synthesized between tetravalent zirconium ion and 5′-(4,5-bis(4carboxyphenyl)-1H-imidazol-2-yl)-[1,1′:3′,1′'-terphenyl]-4,4′'-dicarboylic acid (H4BITD) with the formic acid as the modulator. Zr-BITD was fully characterized by single-crystal and powder X-ray diffraction, thermalgravimetric analysis and fluorescence spectrum. It exhibited excellent chemical stability in the pH range from 0 to 11, while it showed enhanced fluorescence derived from its highly rigid and stable structure. Furthermore, Zr-BITD can be used to effectively detect iodate in the aqueous solution, while the S-V plot is linear in the range of 0∼80 µM with the KSV value up to 8.02 × 103 M − 1 and the limit of detection low to 2.05 μM. This work highlights the opportunity in constructing novel Zr-MOFs for their potential applications in the fluorescent detection of iodate.