Anodized Aluminum with Nanoholes Impregnated with Quaternary Ammonium Compounds Can Kill Pathogenic Bacteria Within Seconds of Contact

Bacterial contamination of surfaces results in the spread of pathogens in public spaces such as hospitals and public transport. The development of antibacterial surfaces that rapidly kill bacteria is therefore highly desirable. Here, we investigate the antibacterial efficacy of a novel anodized aluminum surface featuring nanoholes impregnated with quaternary ammonium compounds, referred to as A3S. The antimicrobial activity of A3S was assessed using both Gram-positive and Gram-negative bacteria in a novel assay which simulates pathogen transfer from a contaminated “finger” to a clean finger in a real-world scenario. Enumeration of colony-forming units shows that the number of viable bacteria on the second “finger” contacting A3S is significantly reduced compared to a control surface. Furthermore, bacterial contact with the A3S material results in compromised cell membranes in less than 1 min, and a kill zone assay shows that an exposure time as short as 5 s is sufficient to kill pathogenic bacteria. The r...