Aloe emodin functionalized dual-channel label with self-adhesion and hydrophobicity for visual monitoring of seafood freshness.

In this study, aloe emodin and β-d-glucose pentaacetate were added into potato starch/polyvinyl alcohol for the construction of colorimetric/fluorescent dual-pass intelligent response labels. Inspired by the lotus leaf structure, retained the advantages of the label itself and solved the hydrophilic problem of the label, and further developed a multi-functional dual-channel smart label with hydrophobicity and self-adhesion. The water contact angle of the prepared T-AEB label was 120.1 ± 0.8°, and the adhesion was 8 to 12 kPa. After burying T-AEB label in the soil for 35 days, the degradation rate reached 85 %, reflecting excellent ecological security. At pH (7-13) and volatile ammonia (25 to 25,000 ppm) conditions, the label's own color would change dramatically to indicate the effect. In sunlight, as the ammonia concentration increases, the color of the label changed from yellow to purplish red. Correspondingly, the fluorescent color of the label changed from yellow to blue. Under a 365 nm UV lamp. In addition, the label was successfully used for freshness monitoring of shrimp and razor clams during storage at 4 °C, 25 °C and - 20 °C. The smart label was a novel, economical, convenient and food freshness dual monitoring system, which was of great significance to improve food safety and quality monitoring.