Two-Luminogen Hydrogel Chemosensor Detects Seafood Freshness by Changing Color Written by AZoMMay 7 2021 A team of researchers from Germany and China has developed a novel artificial color-changing material that imitates the skin of a chameleon, through luminogens (molecules that cause crystals to glow) arranged into different core and shell layers of hydrogels rather than a single uniform matrix. This image shows the color change of the “chameleon skin” hydrogel-based chemosensor in response to biogenic volatile amine vapors, which are a well-known indicator of fish and shrimp spoilage. Image Credit: Lu et al./Cell Reports Physical Science. The results, recently published in the