Ultrasound Irradiation Assisted Synthesis of Luminescent Nano Amide-Functionalized Metal-Organic Frameworks; Application Toward Phenol Derivatives Sensing

Abstract

Two nano amide-functionalized metal-organic frameworks (MOFs) with molecular formula [Co(oba) (bpta)]·(DMF)2 TMU-50 and [Co2(oba)2 (bpfn)]·(DMF)2.5 TMU-51 obtained under ultrasonic method without any surfactants. The only difference between the two selected amide functionalized pillar ligands, N,N′-bis(4-pyridinyl)-terephthalamide (bpta), and N,N′-bis-(4-pyridylformamide)-1,5-naphthalenediamine (bpfn), is related to the naphthyl group, which led to the different luminescence properties of the nano frameworks. In this study, the special ability of the luminescent nano MOFs were investigated to sensitize nitroaromatic compounds. Due to its unique and porous framework, Nano TMU-50 shows a good sensitivity towards nitro phenol by strong fluorescence emission with a detection limit of 2 × 10–3 mM−1. Both nano MOF structures were characterized via many analyses such as powder X-ray diffraction, Field Emission Scanning Electron Microscopy (FE-SEM), elemental analysis, and FTIR spectroscopy. Moreover, the effect of a number of important parameters including initial reagent concentrations, power of ultrasound, time on morphology, and size of nano structures were examined. According to the fluorescence titration results, the activated nano-TMU-50 detected NP selectively with a quick response.

Recent progress of metal–organic frameworks as sensors in (bio)analytical fields: towards real-world applications

“…Ultrasonic-assisted and microwave-assisted methods [ 95 – 97 ] can produce uniformly seeded MOFs with better size control [ 98 , 99 ]. This is the case of a recent study for the preparation of Co-MOFs (TMU-51) by an ultrasound-assisted technique, in which, by tuning the power of ultrasound, smaller particles with controlled morphology were achieved, which finally resulted in an improved sensing performance for nitrophenol detection [ 100 ]. Therefore, advances in unconventional synthetic methods are expected to lead to significant advances in MOF synthesis in the coming years.…”