Selective sensing of aliphatic biogenic polyamines by a zwitterionic Cd-MOF based on bisimidazole tetracarboxylic acid linker

Abstract

<p>A cadmium metal-organic framework, i.e., <bold>Cd-BBI</bold>, with ca. 43% solvent-accessible volume, was accessed starting from a rationally-designed tetraacid linker based on bisimidazole featuring concave shapes as the central core. The...</p>

Anthracene-Bisimidazole Tetraacid Linker-Based Metal–Organic Nanosheets for Turn-On Fluorescence Sensing of Nerve Agent Mimics

“…480 nm is ascribed to the emission arising from the diarylimidazole moiety that is coordinated. Indeed, similar emission has been observed earlier for the linker in which anthracene is replaced with benzene, 54 implying that the central anthracene moiety has no influence on the observed emission; it should be noted that the emission due to anthracene cuts off well below 420 nm. 61 The dispersion of 2D MON in methanol, obtained by UILPE, exhibited Tyndall light scattering (Figure 3), vindicating the fact that methanol delaminates 2D layers from the bulk material.…”

“…Table S1. 54 The assembly of Cd 2+ ions and ANTBI leads to the formation of undulated 2D porous neutral frameworks that stack atop each other with voids propagating down the y-axis, cf. Figure 2.…”

“…Figure ; both anthracene and di/triarylimidazoles are excellent fluorophores. In particular, di/triarylimidazoles exhibit solvent-dependent emission. − The considerations behind our strategy in the design of tetraacid linkers to access 2D LMONs were the following: (i) the 4-connecting square-planar linkers with orthogonally oriented anthracene as a bulged core can predictively lead to 2D polymeric networks upon metal-mediated self-assembly, as has been shown by our recent contributions; , (ii) the concave shapes extant to the linker contribute to creation of free void spaces for guest inclusion, , and this has been amply demonstrated in our research; − ,, and (iii) porosity in conjunction with H-bonding donor–acceptor sites inherent to imidazole moieties presents unique chemical versatility. ,, Herein, the self-assembly of H 4 ANTBI with Cd 2+ ions leading to a layered material, that is, Cd-ANTBI , which upon ultrasound-induced liquid-phase exfoliation (UILPE) affords few-layer 2D MONs by a top-down approach, is demonstrated. It is shown that exfoliation is signaled by fluorescence, which is largely quenched in the bulk material.…”

“…Our own research focus has been centered on the development of functional LMOFs by ab initio development of organic linkers. − Spurred by our own results based on benzimidazole-annulated triptycene-based 2D luminescent MONs (LMONs), whose delamination is signaled by turn-on fluorescence due to disruption of interlayer hydrogen bonds, we sought to leverage an anthracene-based bisimidazole tetraacid organic linker, that is, H 4 ANTBI , to obtain layered LMONs by metal-assisted self-assembly for sensing applications, cf. Figure ; both anthracene and di/triarylimidazoles are excellent fluorophores.…”

MOF sensors for food safety: ultralow detection of putrescine and cadaverine in protein rich foods

“…It is noteworthy that only a handful of fluorescent sensors have been reported to date for the sensing of biogenic amines. [10][11][12][13][14][15][16][17] Most of these sensors comprise purely organic materials. [10][11][12][13][14] Porous materials such as metal organic frameworks (MOFs) possessing a high surface area, permanent porosity, and good thermal and chemical stability with tuneable properties are known for various applications.…”