Solvo-thermal synthesis of a unique cluster-based nano-porous zinc(II) luminescent metal-organic framework for highly sensitive detection of anthrax biomarker and dichromate

In this work a flexible multi-dentate 4,4'-(1H-1,2,4-triazole-1-yl) methylene-bis(benzonic acid) (H2L) ligand has been employed, a unique cluster-based nano-porous luminescent zinc(II) metal-organic framework {[Zn(mu(6)-L)]center dot(DMAC)(2))(n) (1) (DMAC = Dimethylacetamide) has been isolated under solvothermal conditions. The H2L ligand adopts hexa-dentate coordination modes via one triazole nitrogen atom and four aromatic carboxylate oxygen atoms, which bridge the neighboring six-coordinated Zn-II centers, leading to a three-dimensional (3D) nano-porous metal organic framework. A PLATON program analysis suggests the total potential solvent area volume is 2028.9 angstrom(3), which occupy 62.5% percent of the unit cell volume (3248.4 angstrom(3)). PXRD Patterns of the as-synthesized samples 1 have been determined confirming the purity of the bulky samples. Photo-luminescent properties indicate strong fluorescent emissions of 1 at the room temperature. Further photo-luminescent measurements show that 1 can exhibit highly sensitive real-time luminescence sensing of anthrax biomarker dipicolinic acid (DPA) with high quenching efficiency (K-SV = 1.48 x 10(5) M-1) and low detection limit (0.298 mu M (S/N = 3)). Meanwhile 1 also exhibits highly selective and sensitive luminescence sensing for Cr2O72- ions in aqueous solutions with high quenching efficiency K-SV = 1.22 x 10(4) L.mol(-1) and low detection limit (0.023 mu M (S/N = 3)). Therefore 1 can be used a unique multi-functional 3D cluster-based metal organic material in sensitive detection and effective detection of environment pollutants and biomarker molecules. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

A unique cluster-based nano-porous luminescent zinc(II) metal-organic framework has been synthesized using a flexible multi-dentate ligand. The framework exhibits strong fluorescent emissions and shows highly sensitive luminescence sensing capabilities towards anthrax biomarker dipicolinic acid and Cr2O72- ions. This material can be used for the sensitive detection of environmental pollutants and biomarker molecules.