A Terbium‐Based MOF as Fluorescent Probe for Selective Sensing of Nitrobenzene and Fe³⁺

Abstract

A three‐dimensional metal‐organic framework named as [TbL(OH)2](COOH)3·(solvent)x (Tb‐MOF), was successfully obtained by using Tb(NO3)3·6H2O and 1,1′,1″‐(2,4,6‐trimethylbenzene‐1,3,5‐triyl)tris(methylene)‐tris(4‐carboxy‐pyridinium)tribromide (H3LBr3) as raw materials. A series of fluorescence detection experiments demonstrate that Tb‐MOF shows a fluorescence quenching effect on NB. Moreover, Tb‐MOF also exhibits a very fast fluorescence quenching response to trace Fe3+ ions, which is unaffected by the existence of other competitive metal cations. The linear curve between the fluorescence intensity of Tb‐MOF and the concentration of Fe3+ was plotted by the fluorescence titration experiments data. The calculated LOD for Fe3+ ions is 2.86 × 10‐6 M. Therefore, based on the characteristics of Tb‐MOF, it can be regarded as a luminescent sensor for detecting NB and Fe3+. We have also explored the quenching mechanism of Tb‐MOF as a fluorescent sensing material.