Antibacterial Evaluation of Ag/Cu Doped in DLC Coatings
Date
2024-09-23
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
Type
Thesis
Degree Level
Masters
Abstract
The development of antimicrobial coatings is an emerging technology to reduce infections acquired from high-touch surfaces in hospitals. Among these, metal-doped coatings have gained attention for their antimicrobial effects. Diamond-like carbon (DLC) coatings, known for their excellent tribological properties, are also being explored for biomedical applications. This research on the antibacterial activity of metal-doped DLC coatings, particularly those synthesized via magnetron sputtering, has the potential to significantly impact the field of biomedical materials and contribute to the development of safer healthcare environments.
Due to their potent antimicrobial properties, silver (Ag) and copper (Cu) have become increasingly crucial in hospital surface coatings. Despite this, studies explicitly focusing on the antibacterial activity of Ag/Cu-doped DLC are scarce.
In this study, Ag/Cu-DLC coatings were synthesized using the direct current (DC) magnetron sputtering method, with varying Ag target power between 0-20 W and Cu target power between 0-36 W. The coatings' chemical composition and structural characteristics were analyzed using XRD, XPS, Raman spectroscopy, and SEM. The antibacterial activities of the coatings against pathogens Klebsiella pneumoniae and Staphylococcus aureus were evaluated using a modified disk diffusion assay, Minimum Inhibitory Concentration (MIC), and time-course antimicrobial assays.The results demonstrated that Ag/Cu-doped DLC coatings exhibited superior antibacterial properties compared to undoped DLC coatings, mainly when tested in an LB medium. The doped DLC coatings effectively inhibited bacterial growth, making them suitable for application on material surfaces to prevent bacterial spread. The study also highlighted the initial effectiveness of both coatings in inhibiting bacterial proliferation. However, the longevity of this effect differed, with Ag-DLC displaying more prolonged antibacterial action due to the continuous release of silver. At the same time, Cu-DLC showed a rapid decline in effectiveness over time.
Description
Keywords
Antimicrobial , Diamond Like Carbon (DLC), Coating, Magnetron Sputtering
Citation
Degree
Master of Science (M.Sc.)
Department
Mechanical Engineering
Program
Mechanical Engineering