Visible light-trigged photodynamic antibacterial film with mild temperature enhancement for long-term preservation of perishable products

To address the microbial spoilage of perishable products, this study developed an advanced multi-modal antibacterial packaging solution that combines bacterial capture and visible light-driven photothermal synergistic photodynamic antibacterial effects to effectively control microbial growth and prolong preservation. By innovatively combining curcumin-loaded porous hollow carbon spheres with a chitosan matrix, a composite film has been created that demonstrates exceptional visible light utilization performance through the integration of the following innovative characteristics: (i) enhanced electron dynamics that reduce the recombination of photo-generated electrons and holes; (ii) broadened absorption and reflective properties of PHC to maximize visible light utilization; (iii) improved carrier functionality that mitigates the tendency of curcumin to aggregate in water; and (iv) the excellent bacterial capture efficiency of chitosan for the short-range effectiveness of reactive oxygen species. The system achieved a high sterilization rate (99.9 %) after a short treatment with visible light (10 min) and effectively extended the shelf life of kumquats to 27 days. Furthermore, the low hemolysis rate (≤2.0 %) and high 3T3 cell viability (≥ 86 %) demonstrated the biosafety, laying the foundation for the practical application. Above all, the composite film holds great promise as a microbial control barrier, capable of efficiently utilizing visible light for antibacterial preservation of perishable products.