Surface characterization and antibacterial response of silver nanowire arrays supported on laser-treated polyethylene naphthalate

- Polyethylene naphthalate (PEN) foil was patterned by excimer laser.
- Self-organized, well-separated ripples were prepared on PEN surface.
- Rippled PEN was used for the preparation of 20 nm thick Ag nanowire arrays.
- Properties of pristine and laser-patterned PEN were compared with Ag-coated one.
- The results of antibacterial tests revealed strong antibacterial effect of Ag.

Polymeric biomaterials with antibacterial effects are requisite materials in the fight against hospital-acquired infections. An effective way for constructing a second generation of antibacterials is to exploit the synergic effect of (i) patterning of polymeric materials by a laser, and (ii) deposition of noble metals in their nanostructured forms. With this approach, we prepared highly-ordered periodic structures (ripples) on polyethylene naphthalate (PEN). Subsequent deposition of Ag under the glancing angle of 70° resulted in the formation of self-organized, fully separated Ag nanowire (Ag NW) arrays homogenously distributed on PEN surface. Surface properties of these samples were characterized by AFM and XPS. Vacuum evaporation of Ag at the glancing angle geometry of 70° caused that Ag NWs were formed predominantly from one side of the ripples, near to the top of the ridges. The release of Ag+ ions into physiological solution was studied by ICP-MS. The results of antibacterial tests predetermine these novel structures as promising materials able to fight against a broad spectrum of microorganisms, however, their observed cytotoxicity warns about their applications in the contact with living tissues.

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