Antimicrobial activity of cuprous oxide-coated and cupric oxide-coated surfaces

Area of Science:

• Materials Science
• Microbiology
• Surface Chemistry

Background:

• Disease transmission occurs via contaminated surfaces (fomites), implicated in spreading pathogens like MRSA and Pseudomonas aeruginosa.
• Antimicrobial surface treatments offer a strategy to mitigate fomite-mediated disease spread, with broad-spectrum efficacy being highly desirable.

Purpose of the Study:

• To evaluate the antimicrobial efficacy of cuprous oxide (Cu2O) and cupric oxide (CuO) coatings against a panel of 12 microorganisms.
• To assess the durability and safety of these novel antimicrobial coatings.

Main Methods:

• Two surface coatings were fabricated: Cu2O using polyurethane binder and CuO via heat treatment of Cu2O.
• Antimicrobial activity was quantified by counting colony-forming units (cfu) after microbial suspension droplet application.
• Coating durability was tested through abrasion and cleaning procedures; cytotoxicity was assessed using human cells.

Main Results:

• Both Cu2O and CuO coatings exhibited rapid killing of nine diverse microorganisms, including Gram-negative bacteria, Gram-positive bacteria, mycobacteria, and fungi.
• The Cu2O/PU coating achieved over 99.999% reduction of Pseudomonas aeruginosa and Staphylococcus aureus within one hour.
• Antimicrobial efficacy remained consistent after repeated cleaning and abrasion, and the coatings demonstrated no cytotoxicity to human cells.

Conclusions:

• The Cu2O coating possesses broad-spectrum antimicrobial properties, excellent abrasion resistance, and low cytotoxicity.
• These characteristics suggest significant potential for the application of Cu2O coatings in healthcare environments to enhance infection control.