Combining Topography and Chemistry toward Polydopamine Antibacterial Surfaces.

Microporous antibacterial surfaces offer a promising route for preventing bacterial adhesion and biofilm formation, yet their fabrication often involves complex and energy consuming processes. In this work, we present a sustainable strategy for producing multifunctional antibacterial surfaces by combining a microporous cellulose acetate butyrate (CAB) substrate, a bioinspired polydopamine (PDA) coating, and in situ synthesized silver nanoparticles (AgNPs). CAB, selected for its film-forming capability and ease of microstructuring via spin-coating, provides a tunable platform for topographical control. PDA, formed through the oxidative self-polymerization of dopamine, serves as a conformal adhesive layer and simultaneously acts as a reductive matrix for AgNP formation. Immersion in silver nitrate solution enables the direct deposition of AgNPs without external reducing agents, facilitated by the catechol functionalities of PDA. The resulting CAB-PDA-AgNP surfaces exhibit enhanced antibacterial activity through the combined effects of patterning, surface chemistry, and silver-mediated bactericidal action. The fabrication process is low-energy and solvent-minimized, aligning with principles of sustainable material development and offering a versatile platform for antibacterial coatings.