A dynamic word conversion indicator based on water resistance poly (vinyl alcohol)/basic lead acetate nanofibers for monitoring shrimp freshness

Abstract

Visual monitoring of seafood is particularly important for dietary health. Hydrophilic materials provide more direct visual results, yet improving their water resistance while maintaining high sensitivity is challenging. In response, we introduce a visual monitoring fibrous film characterized by high water resistance and sensitivity. A poly (vinyl alcohol)/basic lead acetate (PVA/Pb) nanofiber film responding to hydrogen sulfide (H2S) released during seafood spoilage, employing poly (vinyl alcohol) (PVA) as the support and basic lead acetate (Pb(Ac)2) as the indicator, has been fabricated through electrospinning. Through studies on different crosslinking durations, 4 h was found optimal, giving the film satisfactory water resistance (with a mass loss rate of 35.93%) and sensitivity (2.3 ppm−1), alongside investigations into its operational mechanism. To enhance the widespread application of the PVA/Pb nanofiber film, we employed its color transition from white to brown as a dynamic word conversion indicator (DWCI), accurately indicating shrimp freshness from “edible" to “inedible". This innovative design provides a clear and convenient solution for special populations (including visually impaired individuals, older people, and children), enabling barrier-free real-time detection of seafood freshness.