Microwave-assisted modular fabrication of nanoscale luminescent metal-organic framework for molecular sensing.

Miniaturizing the size of metal-organic framework (MOF) crystals to the nanometer scale is challenging, but it provides more advanced applications without changing the characteristic features itself. It is especially useful to investigate the correlation between the porous properties and the interfacial structures of nanocrystals. Using amino acids as capping agents, nanoscale Tb-MOF-76 is fabricated rapidly by means of microwave-assisted methods. Both the modular effects of the amimo acids and the acid-base environment of the reaction medium have an important impact on the morphologies and dimensions of Tb-MOF-76. The structures of the samples are confirmed by powder X-ray diffraction, and the morphologies are characterized by SEM. Photoluminescence studies reveal that these Tb-MOF-76 materials exhibit a green emission corresponding to the transition (5)D(4) → (7)F(J) of Tb(3+) ions under UV-light excitation, which is sensitive to small organic molecules in solution.