Visual Colorimetric Sensing of the Animal-Derived Food Freshness by Juglone-Loaded Agarose Hydrogel

The visual colorimetric sensing of total volatile basic nitrogen (TVB-N) allows for conve- nient dynamic monitoring of animal-derived food freshness to ensure food safety. The agarose hydrogel loaded with the natural dye juglone (Jug@AG) prepared in this study exhibits visible multicolor changes from yellow to grayish-yellow and then to brownish with increasing TVB-N gas concentration, achieving sensitive detection of TVB-N gas at concentrations as low as 0.05 mg/dm3 within 8 min. The minimum...