Natural Quercetin AIEgen Composite Film with Antibacterial and Antioxidant Properties for in Situ Sensing of Al3+ Residues in Food, Detecting Food Spoilage, and Extending Food Storage Times

Functional materials that can both accurately and conveniently sense food quality and improve food storage times would provide important benefits. To achieve a functional material, which can both sense food quality fluorescently and extend food storage times, a multifunctional film incorporating the natural AIEgen quercetin been has prepared via physically mixing quercetin and poly(vinyl alcohol) in this paper. The as-prepared film was first investigated on the physical properties. The film had a nice mechanical performance and water/CO₂ permeability. Optical properties of the film were subsequently determined by UV-vis and fluorescent spectra. The as-prepared film was transparent and showed a good AIE enhancement when exposed to foods containing Al³⁺ residues and to seafood containing biogenic amines, produced during spoilage. The film also showed good antibacterial and antioxidant activities, which enabled it to be successfully used as a coating to extend food storage times. The film has the potential to be used as a new smart food packaging material, which could both indicate food quality and extend shelf life.