Eco-friendly fabrication of propolis-derived silver nanocomposites on graphene oxide for advanced chitosan-based food packaging

This study presents a sustainable approach for developing multifunctional chitosan (CS) food packaging films by incorporating propolis-mediated silver nanoparticles (AgNPs) anchored onto graphene oxide (GO). The biosynthesized AgNPs (≈51 nm) were uniformly dispersed, and their attachment to GO increased the composite particle size to about 258 nm while enhancing structural stability. GO incorporation strengthened the CS matrix, leading to a 47.62% improvement in tensile strength and effectively limiting AgNP migration. The CS/GO–AgNP films exhibited strong antibacterial activity (83.25–100% inhibition) against Escherichia coli ATCC 15597 and Staphylococcus aureus ATCC 12600 , enabled by the combined effects of AgNPs and propolis, together with a controlled Ag release (33.42–45.34%) that supported sustained antimicrobial function. When applied to blueberries, the films reduced weight loss by 43.32% and surface wrinkling by 49.10%, helping maintain postharvest quality. Structural characterizations (SEM, FTIR, XRD) further confirmed improved uniformity and interfacial compatibility among CS, AgNPs and GO. Overall, this work provides a practical and environmentally friendly strategy for designing high-performance food packaging materials, offering theoretical support and reference for developing antimicrobial systems with enhanced mechanical stability and reduced nanoparticle migration. • Green synthesis of AgNPs using propolis extract (PR) for eco-friendly fabrication. • Graphene oxide (GO) employed as an immobilization template to stabilize PPE-AgNPs effectively. • Chitosan (CS)-based film developed with sustained-release behavior of immobilized Ag NPs. • GO/PPE-AgNPs/CS composite packaging film exhibits superior blueberry preservation.