Bactericidal properties of silver implanted pyrolytic carbon

The bactericidal properties of Ag+-implanted pyrolytic carbon was investigated using gram positive staphylococcus aureus. The pyrolytic carbon samples were implanted by silver ions with the dose ranging from 5 x 1014 to 5 x 1018 ions/cm2 at the energy of 70 keV. The samples were characterized by X-ray diffraction (XRD), Rutherford backscatterring spectrum (RBS) and scanning electron microscopy (SEM). The results show that the bactericidal ratio increases with the ion dose when silver ion dose under the saturated dose of 5 x 1017 ions/cm2. The bactericidal ratio is over 97% when the ion dose exceeds that. RBS analysis shows that the silver atoms penetrate into the sample surface and forms a Gaussian-like distribution in pyrolytic carbon substrate. The sputtering effect is helpful to form a silver-rich surface region which plays an important role to kill bacteria. XRD analysis shows that silver mainly existed in (1 1 1) (2 0 0) (3 1 1) crystal plane in accordance with the fcc crystal structure. SEM characterization shows that the surface morphology also important for killing germs