Antibacterial properties of fluorinated diamond-like carbon films deposited by direct and remote plasma

Abstract

The antibacterial activity and cell viability of fluorinated diamond-like carbon (F-DLC) films as bio coating were investigated. The F-DLC films were deposited on polycarbonate substrates by the radiofrequency (RF) plasma (direct mode) and microwave (MW) afterglow plasma (remote mode). The influences of RF and MW power on the fibroblast cell proliferation and antibacterial activity against E.coli were studied. Additionally the relevance of F atoms concentration, surface roughness and surface energy with the antibacterial activity was investigated. The fibroblast cell cultivation tests revealed that the F-DLC films have no toxicity for cells. Increasing the RF power increased the F concentration and surface roughness, lowered the surface energy and eradicated 70% of E.coli bacteria. A drop in this growing trend happened in the remote mode. As the MW power increased, the F content and surface roughness decreased, the films became hydrophilic, and only thirty percent of bacteria was killed.