Mechanical properties and antibacterial activity of copper doped diamond-like carbon films

A hydrogenated diamond-like carbon (a-C:H) with a copper dopant (Cu/a-C:H) was deposited on glass substrates using a combined radio-frequency plasma and magnetron sputtering deposition process under various Ar/CH₄ gas mixtures. The effects of the Cu content on the structure and properties of the a-C:H matrix were investigated using X-ray diffraction (XRD), Raman transmission electron microscopy, high-resolution transmission electron microscopy (TEM), and nano-indentation. The bacterial activity of a Cu/a-C:H film was evaluated with Escherichia coli (E. coli). TEM images and XRD spectra demonstrated that composite films containing copper nanoparticles embedded in the a-C:H were deposited on the glass substrates. The Raman spectra showed the structure of a-C:H film was substantially changed by the incorporation of Cu. The Cu/a-C:H films offered superior antibacterial activity against E. coli indicating that they could be suitable for surface coatings in cardiovascular applications.