One stone, three birds: Polydopamine-hybridized ZIF-8 for constructing superhydrophobic paper with synergistic photothermal and photodynamic antibacterial activity for active food packaging

The widespread environmental issues caused by plastic packaging have driven the search for sustainable alternatives. In this study, we report a facile and scalable layer-by-layer (LBL) spraying strategy to fabricate superhydrophobic paper-based packaging materials with integrated photothermal and photodynamic antibacterial activities. Cellulose paper was modified through the alternate deposition of collagen (COL) and polydopamine-hybridized ZIF-8 (PDA@ZIF-8) nanoparticles to construct hierarchical micro/nano structures, followed by polydimethylsiloxane (PDMS) treatment. The resulting superhydrophobic paper demonstrated remarkable water repellency, self-cleaning and antibacterial adhesion performance. In contrast to original paper, this functional paper also exhibited enhanced mechanical properties and gas barrier. Under 808 nm near-infrared (NIR) irradiation, it generated localized heat and reactive oxygen species (ROS), achieving up to 100 % inhibition against Staphylococcus aureus and Escherichia coli . Moreover, the modified paper demonstrated good biocompatibility and biodegradability, meeting food safety requirements while addressing environmental sustainability. Preservation packaging tests revealed that this functional paper, when combined with NIR irradiation, effectively preserved the quality and freshness of blueberries for 8 days during ambient storage. This work presents a promising strategy for the development of multifunctional and biodegradable paper-based packaging materials, showing great potential for green and active food packaging applications.