An efficient iodide ion chemosensor and a rewritable dual-channel security display material based on an ion responsive supramolecular gel

Abstract

The ion stimuli-responsive metallogel PbG could act as a highly selective and sensitive I− sensor and a rewritable dual-channel security display material.

A novel acylhydrazone-based self-assembled supramolecular gel for ultrasensitive alternating fluorescence detection of Fe3+ and H2PO4−

“…Although on addition of H 2 PO 4 − to the metal gel Fe-ODN the resulting competitive coordination of H 2 PO 4 − with Fe 3+ occurred, the aggregated state of the gel ODN was not disrupted. 49,50…”

Recent Advances in Aggregation-Induced Emission Chemosensors for Anion Sensing

“…Two iodide-responsive supramolecular organogel systems, A22 and A23 , were separately reported by Wei et al The organogelator A22a (Scheme 4b) could self-assemble with Pb 2+ to form organogel A22 , which exhibited blue fluorescence. Treatment of A22 with iodide ions can reversibly switch off the fluorescence under gel–gel state by competitively binding with Pb 2+ leading to changes in interlamellar supramolecular interactions between A22 and a reduction of π-π stacking distance [67]. Similarly, pillar [5]arene-based organogelator A23a can self-assemble into stable organogel A23 via a series of supramolecular interactions, including hydrogen bonding and host–guest interactions (Scheme 4c), which exhibited blue fluorescence [68].…”

“…Treatment with iodide in the gel–gel state disrupted hydrogen bonding and hence assembly of gel A23 , leading to an 80% decrease in fluorescence intensity. The detection limits of A22 and A23 were determined to be 0.1 μM and 94 nM, respectively, and their iodide-responsive capabilities make them useful as potential fluorescent security display materials [67,68].…”

“…Chemical structures of AIE-based iodide chemosensors A21 ( a ) , A22 ( b ) and A23 ( c ), with selected sensing mechanisms (for A22 and A23 ) shown in ( b ) and ( c ), respectively. Reproduced with permission from [66,67,68]. Copyright 2016 and 2017, the Royal Society of Chemistry.…”

Beyond Covalent Crosslinks: Applications of Supramolecular Gels

“…Upon testing 14 anions, it was discovered the system’s fluorescence could be selectively quenched only with I − . Further addition of Pb 2+ to the system allowed for the effect to be reversed [33]. Two further supramolecular gels investigated by Lin et al, which operate in a similar fashion and are also most stable in ethanol, when coordinated (1) with Mo 2+ and Co 2+ and (2) with Ca 2+ and Fe 3+ could reversibly and visually sense Cl - and H 2 PO 4 − , respectively [34,35].…”