Incorporation of Chlorophyllin-Loaded, Copper-Doped Cyclodextrin-Based Metal–Organic Framework into Microporous Polylactic Acid Coatings for Enhanced Light-Activated Microbial Inactivation

Microbial contamination and cross-contamination of food-contact surfaces remain major challenges to food safety and contribute significantly to spoilage and food waste. Antimicrobial photodynamic inactivation (aPDI) represents a sustainable, nonthermal approach for microbial control, but its effectiveness is often limited by low reactive oxygen species (ROS) generation and poor stability under complex practical conditions. Herein, this study aims to (i) develop a copper (Cu)-doped cyclodextrin-based metal–organic framework to enhance the photodynamic activity of CCS, thereby increasing ROS generation and light-activated antimicrobial efficacy; and (ii) incorporate the resulting CCS-loaded, Cu-doped cyclodextrin-based metal–organic framework (CCS/MOF-Cu) nanoparticles into a microporous polylactic acid (PLA) coating to enable a light-activated antimicrobial surface. The CCS/MOF-Cu was synthesized via a rapid microwave-assisted method and exhibited enhanced aqueous stability for at least 30 days. The Cu-doped framework demonstrated an approximately 140-fold enhancement in ROS generation compared to free CCS. A phase separation strategy produced microporous surfaces that promote bacterial localization and improve ROS–microbe interactions. The resulting coating achieved a >5-log reduction of Pseudomonas fluorescens and Bacillus cereus within 30 min of red LED exposure. This work demonstrates a scalable coating platform that integrates ROS amplification with an engineered surface design, offering a promising self-disinfecting solution to reduce microbial risks in food systems.