Nanocomposite multifunctional polyelectrolyte thin films with copper nanoparticles as the antimicrobial coatings.

The work presents the formation and physicochemical characterization of polyelectrolyte-copper nanocomposite coatings using: poly(diallyldimethylammonium chloride) (PDADMAC) as a polycation, poly(sodium 4-styrenesulfonate)(PSS) as a polyanion and negatively charged copper nanoparticles (CuNPs) to obtain biocompatible surfaces with an antibacterial functionality. The mass and thickness of composite films were investigated by the quartz crystal microbalance with dissipation monitoring (QCM-D) and the ellipsometry whereas, the structure and morphology of coatings were examined using scanning electron microscopy (SEM). The increase of the UV-Vis absorption confirmed the formation of the consecutive layers of the film. Antibacterial activity of the coatings was tested on a representative Gram-positive bacteria strain, Staphylococcus aureus. The microbiological tests were performed and bacteria visualized using fluorescent staining and microscopic technique. It was demonstrated that nanostructured films had antibacterial properties, which makes polyelectrolyte multilayer films containing copper an interesting material in biomedical applications area, e.g., for the prevention of microbial deposition on surfaces.