Antimicrobial properties of a multi-component alloy.

Area of Science:

• Materials Science
• Microbiology
• Surface Chemistry

Background:

• High-touch surfaces like doorknobs are pathogen transmission points.
• Developing self-sanitizing materials is crucial for public health.
• Metals offer durability and inherent antimicrobial properties.

Purpose of the Study:

• To create synergistic metallic alloys for broad-spectrum, rapid self-sanitation.
• To investigate alloys of copper, silver, nickel, and cobalt using an entropy-motivated stabilization paradigm.
• To assess the antimicrobial efficacy of these alloys against various pathogens.

Main Methods:

• Combinatorial sputtering was used to create thin-film alloys with compositional grading.
• Films were annealed to investigate alloy stability.
• Antimicrobial activity was tested against Phi6, MS2, Bacillus subtilis, and Escherichia coli.

Main Results:

• Some alloys achieved a >6.9 log reduction of Phi6 (SARS-CoV-2 surrogate) in 30 seconds.
• Significant log reductions were observed for MS2, E. coli, and B. subtilis.
• Antimicrobial activity strongly correlated with copper content; annealing enhanced efficacy in some samples.

Conclusions:

• Synergistic metallic alloys show promise for developing effective antimicrobial surfaces.
• Compositional control and annealing are key factors in optimizing self-sanitizing properties.
• These findings provide a foundation for designing advanced antimicrobial materials.