Copper-containing plasma polymer surfaces: Interface-controlled incorporation, release behavior, and antibacterial functionality

The controlled functionalization of material surfaces with antimicrobial properties requires a detailed understanding of the relationship between surface composition, interfacial structure, and the release of active species. In this work, copper-containing plasma polymer surfaces are fabricated using a DC-driven atmospheric-pressure plasma jet, enabling controlled incorporation and spatial distribution of copper within a hydrocarbon matrix. X-ray photoelectron spectroscopy (XPS) combined with depth profiling reveals the chemical state and distribution of copper across the near-surface region, while atomic absorption spectroscopy (AAS) is used to quantify copper release into aqueous environments. The results demonstrate that plasma deposition parameters govern copper incorporation and its interfacial distribution, which in turn controls release kinetics. A direct correlation between surface composition, copper release, and antibacterial performance against Staphylococcus aureus is established. Furthermore, cytocompatibility studies with osteoblast-like cells indicate that controlled copper incorporation enables antibacterial functionality while maintaining cell compatibility. These findings highlight the critical role of interface-controlled copper distribution in determining functional performance and demonstrate a versatile plasma-based approach for designing biofunctional surfaces with tunable properties.