A multifunctional gelatin-based bifunctional film for visual ratiometric fluorescence detection of hydrogen peroxide...

Hydrogen peroxide (H₂O₂) is a widely used bleaching agent in food processing, and excessive intake of residual H₂O₂ can cause severe health risks to humans. Herein, a bifunctional gelatin film that combined H₂O₂ ratio fluorescence sensing and antibacterial capability was developed. Two functional units, aggregation-induced emission (AIE)-featured silica nanoprobe (TSN) with specific fluorescence response to H₂O₂ and europium-based complex Eu(AC)₃OP with antibacterial activity, were co-doped into a gelatin matrix, with glycerol used as a plasticizer. The ratio fluorescence film was finally fabricated via intermolecular hydrogen bonding cross-linking, which exhibited sensitive, selective, and visual ratiometric detection of H₂O₂, with a detection limit as low as 23 μM. It also achieved outstanding antibacterial activity against Escherichia coli and Staphylococcus aureus, with an inhibition rate up to 99%. This flexible film enables real-time monitoring of excessive residual H₂O₂ in chicken wings via adjacent placement. Moreover, the film exerts antibacterial activity on food surfaces to extend shelf life and maintain food quality. Furthermore, it can be naturally degraded in soil. Our work reveals that the proposed bifunctional film holds great promise in the fields of chemical analysis and food safety.