Electrochemical Assessment of Cu-PIII Treated Titanium Samples for Antimicrobial Surfaces

Abstract

Titanium implant surfaces should ideally be designed to promote the attachment of target tissue cells. At the same time they should prevent bacterial adhesion, achievable through specific modification strategies. Copper could be well-suited as an antimicrobial finish, since it combines good antimicrobial properties with a certain bio-tolerance with regard to eukaryotic cells. In the present contribution, we evaluate electrochemical results of antimicrobial titanium surfaces generated by the insertion of copper. The surface was prepared via copper implantation into the titanium subsurface by means of plasma-immersion ion implantation (Cu-PIII) until a depth of about 30 nm. The amount and profile of copper ion implantation was changed by variation of the pulse length which was equivalent to the duty cycles of 0.2 % up to 90 %. Specimens containing 3 – 12 % copper (XPS) were used for electrochemical investigations with the help of the mini cell system in 0.9 % NaCl solution. The change in the shape of cyclic voltammograms demonstrated an alteration of the electrochemical behaviour. Copper oxidation peaks appeared in copper-implanted samples and their height was proportional to the copper concentration. These peaks are related to an electrochemical activity and not suppressed by the superficial titanium oxidation.