Sustainable Gamma-Crosslinked Hyaluronic Acid-Carbon Quantum Dots Films for Active Packaging and Extended Fruit Shelf Life

This study presents a sustainable approach for developing multifunctional hyaluronic acid–TMSPMA hydrogel films incorporated with banana stem-derived carbon dots (BCDs) via gamma radiation. The solvent-free radiation process enables sterile synthesis, homogeneous crosslinking, and uniform BCD distribution. FTIR and XPS confirmed oxygen- and nitrogen-rich functional groups on BCDs; TGA demonstrated excellent thermal stability. The nanocomposite films (HT series) exhibited improved structural integrity, enhanced thermal resistance, and smooth compact morphology. Cytocompatibility verified non-toxicity and biocompatibility. Surface and barrier analyses indicated increased hydrophilicity and reduced oxygen/moisture permeability. The films showed strong antioxidant performance exceeding 60% (DPPH) and 70% (ABTS) radical scavenging for HT3, and a controlled, diffusion-mediated BCD release. In banana packaging, the films delayed ethylene and CO2 evolution, prolonging shelf life and reducing greenhouse gas emissions. Overall, this work introduces a green and scalable route for producing BCD-reinforced hydrogel films combining antioxidant functionality, biocompatibility, and biodegradability for next-generation active food packaging.