Antimicrobial activity of copper and copper(i) oxide thin films deposited via aerosol-assisted CVD

Hospital acquired infections are prevalent in many hospitals and contaminated touch surfaces are a route of transmission. To find a solution for this, copper and copper oxide thin films were deposited via aerosol assisted chemical vapour deposition using copper nitrate as the precursor and the films were characterised by a range of techniques including powder X-ray diffraction and scanning electron microscopy. The antimicrobial activity of the deposited copper and copper oxide films were investigated against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). A 5-log₁₀ reduction in the viable counts of E. coli was observed on the copper thin films after 30 minutes while a 2-log₁₀ reduction was observed on copper oxide films after 1 hour. In the case of S. aureus both copper and copper oxide films exhibited 4-log₁₀ reduction after 1 hour. The high antimicrobial efficacy of the Cu₂O films, approaching that of the pure copper films, suggests that oxide formation on copper objects should not significantly impair their antimicrobial activity.