Bis-naphthalimide-based supramolecular self-assembly system for selective and colorimetric detection of oxalyl chloride and phosgene in solution and gas phase

Reusable, Green, Portable Ionogels Based on Terpyridine-Imidazole Salt for Visual Monitoring of Pork Spoilage

Ionogels have emerged as a promising approach because they combine the advantageous properties of ionic liquids and gels. Herein, a novel gelator bearing terpyridine and imidazolium salt units was designed and synthesized, which assembled into ionogels in three ionic liquids by a heating-cooling procedure. The properties of ionogels were characterized by FT-IR, UV-vis spectroscopy, POM, XRD, and rheology, and resonance light scattering and opacity measurements were conducted to investigate the gelation kinetics. Furthermore, the ionogels incorporating pH-sensitive dyes (BTB and MR) were exploited as colorimetric sensor to monitor total volatile basic nitrogen (TVB-N) of meat at -4 °C, which can easily and reliably estimate the quality of meat by naked eye recognition, and the results demonstrated a positive correlation between the color variation and TVB-N levels. Notably, the hydrophobic ionogel indicators are more suitable for potential application at high humidity thanks to their antiswelling advantage, which could prevent the inaccurate information produced by hydrogel indicators. In addition, the ionogels could be reused up to three times as colorimetric indicators, suggesting potential applications and competitiveness. Our research sheds new light on the novel application of ionogels in the food industry.

Comparison and analysis of mechanism of β-lactoglobulin self-assembled gel carriers formed by different gelation methods

Based on the findings of our previous studies, a comprehensive comparative investigation of the quality and formation mechanism of gels obtained from protein self-assemblies induced by different methods is necessary. Self-assembled heat-induced gels had higher gel mechanical strength, and hydrophobic interactions played a greater role. Whether or not heat treatment was used to induce gel formation may play a more important role than the effect of divalent cations on gel formation. Hydrogen bonds played an important role in all gels formed using different gelation methods. Furthermore, Self-assembled cold-induced gels were considered to can load bioactive substances with different hydrophilicity properties due to the high water-holding capacity and the smooth, dense microstructure. Therefore, β-lactoglobulin fibrous and worm-like self-assembled cold-induced gels as a delivery material for hydrophilic bioactive substances (epigallocatechin gallate, vitamin B2) and amphiphilic bioactive substance (naringenin), with good encapsulation efficiency (91.92 %, 97.08 %, 96.72 %, 96.52 %, 98.94 %, 97.41 %, respectively) and slow-release performance.

Bis-Pyridine-Based Organogel with AIE Effect and Sensing Performance towards Hg2

A novel gelator (1) based on a bis-pyridine derivative was designed and synthesized, which could form stable gels in methanol, ethanol, acetonitrile, ethyl acetate, DMF/H₂O (4/1, v/v) and DMSO/H₂O (4/1, v/v). The self-assembly process of gelator 1 was studied by field emission scanning electron microscopy (FESEM), UV–vis absorption spectroscopy, fluorescence emission spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction and a water contact angle experiment. Gelator 1 exhibited obvious AIE behavior. On the base of its AIE, the gel of 1 could detect Hg²⁺, which resulted in fluorescence quenching and a gel–sol transition. ¹H NMR titration experiments with Hg²⁺ revealed that the metal coordination interaction induced the fluorescence quenching and the breakdown of the noncovalent interaction in the gel system. This research provides a new molecular mode for designing a functional self-assembly gel system.