Multiple-state pattern encrypted superhydrophobic-icephobic colorimetric sensing film for anticounterfeiting and food freshness monitoring

Exploring high-sensitive and convenient anticounterfeiting as well as food freshness monitoring technologies to combat food safety is urgently needed but remains a great challenge. Herein, the color dynamic response and transparency encryption features of colorimetric label with heteronetwork structure can effectively cope with the above problems. The colorimetric label demonstrates excellent superhydrophobic with water contact angle of 156.2° and roll-off angle of 8.9°, and icephobic that delays the freezing time of 40 μL water droplets from 38 s to 162 s and reduces the bonding strength of ice from 249.00 kPa to 15.20 kPa. Furthermore, the colorimetric label exhibits a colorimetric shift of 126 nm and a detection limit of 0.8 ppm for NH3, making it successfully applicable for shrimp freshness monitoring. Notably, a locking encryption system featuring multiple logics can be achieved by combining the colorimetric properties and transparency changes of the colorimetric tags. This work proposes an ingenious, cost-effective, and convenient dual system for anticounterfeiting and food freshness monitoring, which inspired the development of an intelligent monitoring system for food quality, and has significant implications for enhancing food safety.