Pore wall functionalized ultrasonically synthesized cooperative MOF for luminescence sensing of 2,4,6-trinitrophenol

Abstract

Adjustments of morphology and surface area increment with the help of ultrasonic method for tunability of Luminescent MOFs make them more attractive to detection applications. More incoming guest analytes interact with the surface led to the enhanced sensitivity and selectivity of MOFs. Here in, we evaluated fluorescence quenching of bulk and nanostructure ultrasonically synthesized (nanorod) cooperative TMU-33 ([Cd3(BDC)3(OPP) (DMF)2].2DMA), (OPP:N,N’-(oxybis (1,4-phenylene)) bis(1-(pyridin-4yl) methanimine)) in the presence of nitro analytes. This strategy combined the advantages of fluorescent cooperative TMU-33 and nanoscale structures, which not only provide simultaneously imine functional group and open metal site but also promoted the interaction of the analyte with recognition sites in the pore channel. The nanorod TMU-33 demonstrated a superior selective quenching ability in the presence of 2,4,6-Trinitrophenol (TNP) with the high quenching constant (9.3 ​× ​105 ​M−1), which is 10.6 times better than of bulk TMU-33. This unprecedented selectivity could be attributed to effective interaction of guest with accessible free Brønsted base N atoms of imine sites of nanorod TMU-33. The PXRD patterns of the structures indicate the high stability of this compound after 3 times sensing. This study shows the effect of nanostructures in helping to the detection of TNP by the MOF and could be a path for further studies in this area.