Synthesis of fluorescent MOFs: live-cell imaging and sensing of a herbicide?

CrystEngComm Pub Date: 2020-06-22 DOI: 10.1039/D0CE00490A

Abstract

Various zinc and cadmium containing metal–organic frameworks using the semi-rigid 1,1′-(anthracene-9,10-diylbis(methylene))bis(pyridin-1-ium-4-olate) ligand (L = AHP) and various sulfonic acid analogs [1,5-naphthalenedisulfonic acid (1,5-NDS), 3-sulfobenzoic acid (3-SBA), 4-sulfobenzoic acid (4-SBA), 5-sulfosalicylic acid (SSA), 5-sulfoisophthalic acid (SIA) and 2,6-naphthalenedisulfonic acid (2,6-NDS)] have been synthesized by a hydrothermal method. They have been characterized by powder X-ray diffraction thermogravimetric analysis and single crystal X-ray diffraction methods. The X-ray studies showed that MOF2, 4, and 8 have two dimensional architectures whereas 1, 3, 5, 6 and 7 have three-dimensional structures. The topological analysis demonstrated that all the zinc-containing MOFs have a hexagonal (hcb) net topology with the point symbol of the framework being {63} whereas cadmium-containing MOF4 has an sql net topology with the point symbol of the framework being {44·62} and MOF5 has a hcb net topology with the point symbol of the framework being {63}. Since all synthesized MOFs have fluorescence properties, they have been used as imaging agents for MCF7 cells. The cytotoxic experiments show that more than 92% cells survive at the dose 100 μg ml?1. The cell imaging results show that the MOF particles were found in the cytoplasm rather than in the nucleus and these can be used further as a conjugate with any known anti-cancer drugs in cellular distribution. The emission properties of these MOFs have been utilized for the detection of a herbicide (simazine) as well as nitroaromatic compounds. The quenching constant for PA (picric acid) in MOF7 was found to be 5.01 × 104 M?1, which may be due to the interaction of picric acid and co-ligands present in MOF7.

Graphical abstract: Synthesis of fluorescent MOFs: live-cell imaging and sensing of a herbicide
Recommended Literature