Ratiometric Turn-On Fluorophore Displacement Ensembles for Nitroaromatic Explosives Detection

Abstract

There is a recognized need in the area of explosives detection for fluorescence-based sensing systems that are capable of not only producing a turn-on response but also generating a distinctive spectral signature for a given analyte. Here, we report several supramolecular ensembles displaying efficient fluorophore-displacement that give rise to an increase in fluorescence intensity upon exposure to various nitroaromatic compounds. The synthetic supramolecular constructs in question consist of a tetrathiafulvalene (TTF)-based pyrrolic macrocycle, benzo-TTF-calix[4]pyrrole (Bz-TTF-C4P), and fluorescent dyes, namely monomeric or dimeric naphthalenediimide (NDI) and perylenediimide (PDI) derivatives, as well as chloride or hexafluorophosphate (PF6 -) salts of rhodamine 6G (Rh-6G). In chloroform solution, these assemblies exist in the form of discrete supramolecular complexes or oligomeric aggregates depending on the specific dye combinations in question. Each ensemble was tested as a potential explosiveresponsive fluorescence indicator displacement assay (FIDA) by challenging it with a series of di-and tri-nitroaromatic compounds and examining the change in fluorescence spectral characteristics. Upon addition of nitroaromatic compounds (NACs), either a "turn-on" or a "turn-off" fluorescent response was observed depending on the nature of the constituent fluorophore and, where applicable, the counter anion. The FIDAs based on the PDI derivatives were found to display not only a ratiometric fluorescence enhancement but also analyte-dependent spectral changes when treated with NACs. The NAC-induced fluorescence spectral response of each ensemble was rationalized on the basis of various solution-phase spectroscopic studies, as well as single crystal X-ray diffraction analyses.

Design, synthesis and photophysical properties of novel star-shaped truxene-based heterocycles utilizing ring-closing metathesis, Clauson–Kaas, Van Leusen and Ullmann-type reactions as key tools

“…Basically, our interest to generate pyrrole-based C 3 -symmetric truxene derivatives was because of a range of applications of the pyrrole moiety in diverse fields, for instance, a wide variety of medicinally active as well as smart functional materials possessing the pyrrole as a fundamental subunit [28][29][30]. Additionally, 3,4disubstituted pyrrole derivatives are versatile building blocks for the production of diverse bioactive molecules like co-enzyme, alkaloids, porphyrins and other related macrocycles [31,32]. Moreover, polypyrrolic systems are of extensive interest in numerous areas namely optics, medicine, and supramolecular chemistry in addition to the materials sciences and technology.…”

Revisiting β-dicyanovinyl substituted calix[4]pyrrole : toward the highly selective detection of hydrazine in solution

“…C4P possess a built-in recognition site able to recognize anions or polar guests, while its functionalization at the level of meso-carbon or pyrrole allow to achieve cation or ion-pair recognition. [16][17][18] . In this study, we repurposed a β-dicyanovinyl substituted C4P preliminary designed for the recognition of cyanide ion in order to achieve the naked eyed and spectroscopic detection of hydrazine.…”

Emergent Photostability Synchronization in Coassembled Array Members for the Steady Multiple Discrimination of Explosives

“…Driven by concerns in homeland security, military operation safety, and environmental and industrial safety control, many advances in fluorescent detection of explosives pioneered by DOI: 10.1002/advs. 202102739 Swager and co-workers [1,2] have been made, [3][4][5][6][7][8][9][10][11][12][13][14][15] including successful commercialization for real field applications. [12,14,15] In addition to simple detection, identification of the class of explosives based on fluorescent sensor arrays has also been developed.…”