One‐Step Nanoimprinting of Fe₂O₃/AgBr Thin Films for Dark‐Light Active Antibiofilm and Bacterial‐Free Cell Culture Surfaces

The resuscitation of bacteria through biofilms presents a critical challenge in controlling microbial pathogenesis and addressing antimicrobial resistance. Continuous antibiofilm activity, particularly on frequently contacted surfaces, is therefore critical. In this study, a scalable is introduced, one-step fabrication of Fe₂O₃/AgBr nanoimprints using a polymerizable sol-gel (PSG) approach to create functional nanostructured thin films with strong antimicrobial properties. Fe₂O₃, a visible-light photocatalyst, is coupled with AgBr, a photosensitizer and dark-active antimicrobial, forming a heterojunction that demonstrated potent antibacterial activity against Escherichia coli and Pseudomonas putida under both dark and light conditions. The heterojunctions exhibit significant biofilm inhibition in the dark, particularly against the robust biofilm-forming P. putida, while visible light irradiation ensures complete biofilm clearance. These surfaces also achieve optimal reactive oxygen species (ROS) production, selectively targeting bacteria without compromising the integrity of mammalian cells. The biocompatibility is confirmed through MTT, TBARS, and apoptosis assays, demonstrating the non-cytotoxic nature of the substrates. Moreover, the surfaces enable cell patterning and recovery of mammalian cells from microbial contamination, highlighting their potential in creating bacterial-free environments for cell culture. This innovative method offers a promising route to next-generation, self-cleaning antimicrobial coatings, combining continuous biofilm inhibition with excellent biocompatibility and scalability.