Hydroxypropyl Guar/Cellulose Nanocrystal Film with Ionic Liquid and Anthocyanin for Real-Time and Visual Detection of NH₃

Abstract

Simple, fast, and accurate detection of food freshness is of considerable significance to ensure food safety. The pH values of foods can be good indicators of their freshness, which can be used for real-time detection of food quality. Herein, we fabricated a pH-sensing film for flexible smart labels based on hydroxypropyl guar (HPG), cellulose nanocrystal (CNC), 1-butyl-3-methylimidazolium chloride (BmimCl), a kind of ionic liquid (IL), and anthocyanin (Anth). We investigated the structure, optical properties, and mechanical strength of the composite films. These films can be used to detect ammonia (NH 3 ) generated from seafood during storage by pH-sensing capability and monitor the real-time freshness of seafood. The HPG/CNC/IL/Anth film exhibited several advantages, such as wide color-change range, easy identification, high sensitivity, good reversibility, excellent stability, and low detection limit. The pH-sensing films can function as flexible smart labels for real-time, visual, and accurate detection of food freshness in cold chain logistics and other fields.

Novel Anthocyanin-Based Colorimetric Assay for the Rapid, Sensitive, and Quantitative Detection of Helicobacter pylori

“…Anthocyanins act as food additives and as a natural food colorant pigment. Compared to synthetic dyes, they are preferred in many areas from food to cosmetics due to both their safety and pharmacological effects. − As noted above, with its major component consisting of anthocyanins, RCE was found to be a stable, sensitive, cheap, and biocompatible pH indicator in this work. We detected H.…”

A solid-state fluorescent probe for α,β-diamine based on tetraphenylethylene skeleton construction

“…1 H NMR spectra were recorded on a Bruker DPX 400 spectrometer ( 1 H: 400 MHz, 13 C: 100 MHz) in CDCl 3 unless otherwise stated. Spectra were referenced internally using the residual solvent resonances (d = 7.28 ppm from CDCl 3 for 1 H NMR) relative to SiMe 4 (d = 0 ppm).…”

“…Spectra were referenced internally using the residual solvent resonances (d = 7.28 ppm from CDCl 3 for 1 H NMR) relative to SiMe 4 (d = 0 ppm). 13 C NMR spectra were referenced internally by using the solvent resonances (d = 77.00 ppm for CDCl 3 ). Ground state UV-vis absorption spectra were recorded on a Hitachi U-2900 spectrophotometer.…”

“…In recent years, solid fluorescent sensors have been widely used in the amine detection due to their advantages of high selectivity and portability. [12][13][14] In particular, as one of the most promising fluorescent dyes, the aggregation-induced emission (AIE) fluorophore 15 showed a unique advantage in solid state fluorescent sensors, which could emit strong fluorescence in the aggregation state. The reported responsive mechanisms of the solid-state AIE sensors include inducing aggregation or restricting the intramolecular motion of AIE dyes 16 with functional group reaction, 17 photoactivated cycloaddition, 18 bioconjugation 19 and photophysical processes, such as photoinduced electron transfer (PET), 20,21 intramolecular charge transfer (ICT), 22 energy transfer (ET) and excited intramolecular proton transfer (ESIPT).…”

Chiral Cellulose Nanocrystal Humidity-Responsive Iridescent Films with Glucan for Tuned Iridescence and Reinforced Mechanics

“…Practically, biopolymers (such as polysaccharides) act as the main material of composite films, and CNCs act as reinforcing materials. − Nevertheless, there are some reports concerning biocomposites with CNCs as the main component and polysaccharides as the additive. In addition, there have been successful cases of using glucose as an additive to prepare CNC films .…”