Sequential and recyclable sensing of Fe3+ and ascorbic acid in water with a terbium(iii)-based metal–organic framework

• Published in: Dalton transactions : an international journal of inorganic chemistry 2019-06, Vol.48 (24), p.8911-8919
• Main Authors: Ke-Yang, Wu, Liang, Qin, Cheng, Fan, Shao-Lan, Cai, Ting-Ting, Zhang, Chen, Wen-Hua, Xiao-Yan, Tang, Jin-Xiang, Chen
• Format: Article
• Language: English
• Subjects: Absorption spectra; Ascorbic acid; Computer simulation; Crystallography; Density functional theory; Dimensional stability; Emission; Excitation spectra; Ferric ions; Fluorescence; Gravimetric analysis; Ionization; Ions; Luminescence; Mass spectra; Metal-organic frameworks; Porosity; Synthesis; Terbium; Ultraviolet radiation; Urine
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c9dt00871c

A water-stable three-dimensional (3D) metal–organic framework (MOF) of {[Tb(Cmdcp)(H2O)3]2(NO3)2·5H2O}n (1, H3CmdcpBr = N-carboxymethyl-(3,5-dicarboxyl)pyridinium bromide) has been synthesized and characterized. MOF 1 is highly emissive, giving rise to green luminescence that can be quenched by Fe3+ due to the partial overlap of its excitation spectrum with the absorption spectrum of Fe3+. The subsequent introduction of ascorbic acid (AA) leads to the reduction of Fe3+ into Fe2+, accompanied by the near-entire recovery of MOF 1 emission. The density functional theory (DFT) calculation results support the proposed mechanism. Such a sensing cycle is further transferable to urine and serum samples with a satisfactory near-quantitative recovery, highlighting its good potential in biologically relevant applications.