Antibacterial Au nanostructured surfaces

We present here a technological platform for engineering Au nanotopographies by
templated electrodeposition for antibacterial surfaces. Three different types of nanostructures were
fabricated: nanopillars, nanorings and nanonuggets. The nanopillars are the basic structures and are 50 nm
in diameter and 100 nm in height. Particular arrangement of the nanopillars in various geometries formed
nanorings and nanonuggets. Flat surfaces, rough substrate surfaces, and various nanostructured surfaces
were compared for their abilities to attach and kill bacterial cells. Methicillin-resistant Staphylococcus
aureus, a Gram-positive bacterial strain responsible for many infections in health care system, was used
as the model bacterial strain. It was found that all the Au nanostructures, regardless their shapes, exhibited
similarly excellent antibacterial property. The comparison of live cells attached to nanotopographic
surfaces showed that the number of live S. aureus cells was < 1 % of that from flat and rough reference
surfaces. Our micro/nanofabrication process is a scalable approach based on cost-efficient selforganization
and provides potential for further developing functional surfaces to study the behavior of
microbes on nanoscale topographies.