Synergistic Effect of ZnO Thin Films with Gold as Antifungal Coatings

Microbial contamination on surfaces is a problem worldwide, affecting public health and industry. The increasing prevalence and severity of microbial infection outbreaks across various environments have highlighted the urgent need to develop antimicrobial coatings/surfaces to mitigate the risk of disease transmission through high‐touched surfaces. This work focuses on assessing the antifungal activity of thin films based on zinc oxide (ZnO), produced by reactive magnetron sputtering with varying thicknesses, and evaluating the impact of varying gold concentrations within the ZnO matrix on both microstructure and antifungal activity. The developed thin films exhibit noteworthy antifungal activity against the fungus Candida albicans, achieving 80% reduction in cell viability, regardless of thickness and gold concentration (up to 15.4 at%). Annealing treatment at 600 °C induces the formation of large and irregular gold nanostructures (sizes from 39 to 260 nm), enhancing the antifungal activity compared to the as‐deposited samples. This highlights the surface‐dependent antifungal efficacy of ZnO‐based thin films and a synergistic effect when combined with gold. Additionally, the thin films not only exhibit antifungal activity but also demonstrate potential for localized surface plasmon resonance applications. Overall, ZnO‐based thin films hold promise as antifungal coatings for diverse surfaces, offering a preventive measure against microbial contamination.