A pH-Stable Tb-MOF as Luminescence Sensor for Highly Sensitive Detection of Amino Acids through Diverse Sensing Mechanism
Runzhong Guo, Ting-Hui Mai, Zhen-Ni Yang, Haiying Wang, Huiyan Liu
Abstract
A luminescent Tb-MOF with excellent stability and dual-emitting properties was constructed with an amide-functionalized tetracarboxylate ligand. Tb-MOF s were initially assembled on one-dimensional Tb 3+ chains, then formed a two-dimensional double–decker layer through the synergistic linking of organic ligands and bridging formic acid anions, and further fabricated the final three-dimensional structure through the connection of the organic ligands. Powder X-ray diffraction experiments revealed that Tb-MOF s not only exhibited excellent stability in water but also maintained structural integrity in the pH range of 2–12. Importantly, this Tb-MOF provided the first example of a metal–organic framework (MOF)-based luminescence sensor that can simultaneously detect two acid amino acids (aspartic and glutamic acids) through a turn-off sensing mechanism and two basic amino acids (lysine and arginine acids) through unusual turn-on and turn-off-on sensing mechanisms. Moreover, high sensitivity, low detection limit, and excellent recyclability of this sensor endow Tb-MOF s with great potential as a highly efficient amino acid fluorescence sensor in chemical detection and biological environments.