Antibacterial properties obtained by low-energy silver implantation in stainless steel surfaces

- Silver implanted at low energies in stainless steel surfaces
- Ion plating diversified (IPD) is an effective and economical surface treatment technique.
- IPD process use low energies to implant silver atoms with high bactericidal activity.
- Silver ions are antibacterial agents used to prevent the biofilm formation.
- Inhibit bacterial adhesion depends of silver areal density and implantation depth.

Biofilm formations on contact surfaces is one of the main causes in several health and food industries due the high incidence of pathogenic contaminations. An approach to reduce problems is to modify the surface properties with antibacterial or antibiofilm agents. The surface modification before biofilm formation reveals to be an effective technological alternative to prevent or eradicate bacterial adhesion in biomedical devices and surgical instruments, as well as food contaminations from process equipments. In this paper we evaluated the antibacterial properties of silver atoms incorporated on stainless steel surfaces by ion implantation at low energy (4 keV) using a reactive low voltage ion plating-type equipment. The simulations by the Monte Carlo method contributed to establish the minimum self-bias voltage used in the implantation process and to provide an ideal distribution estimate of the silver dose in-depth. The surface modifications in all samples were analyzed by RBS, GD-OES and XPS. The microbiological assays were conducted using Escherichia coli and Staphylococcus aureus, and the results demonstrated an initial reduction on bacterial adhesion, and delay of the biofilm formation. The results help clarify the physicochemical conditions required to obtain a surface resistant to bacteria colonization.