Electrochemical measurements to predict the antifungal properties of nanostructured thin films

Fungi and bacterial infections are an important problem in modern medicine and in hospitals. Even though specific drugs are available to treat these infections, a preventive solution to avoid the proliferation of such bacteria would be extremely interesting in many biotechnological applications. Silver and copper metals have antifungal and bacteriostatic properties, however a real challenge will be to obtain a continuous release of metal species in a controlled way. In this work metal/polymer nanocomposite coatings were deposited by reactive magnetron sputtering; Cu nanoparticles were incorporated in a SiOx thin film to obtain a large effective surface for metal ion release. The nanocomposite coatings were characterised by Electrochemical Impedance Spectroscopy and ion release measurements were performed to assess their bioactive behaviour against fungi. Specific tests have been performed by using both a direct measurement of the released ions amount and by means of an electrochemical impedance measurement. Both tests confirmed the possibility of obtaining such a release for more then ten days by using extremely thin coatings of the order of 100 nm, which could easily be added to any implant.