ANTIMICROBIAL EFFECT OF SILVER NANOPARTICLE-BASED THIN FILMS

The global pandemic of disease COVID-19 caused by the pathogenic SARS-Cov-2 virus brought more interest in the public health community for known silver with its potential antimicrobial properties to fight infection. One of the ways to stop virus to protect community transmission is the application of nanotechnology of silver nanoparticles on the exposed surfaces of daily used materials in public, e.g., transportation, community spaces, hospitals, and everywhere where the potential infection load is increased. Published technology to coat AgNPs on surfaces differs in the preparation of nanocomposites and substrates, which results in different mechanical and antimicrobial properties. In our study, we focused on the properties of AgNPs prepared by HiTUS and PVD technology with a challenge to test the antimicrobial effect towards the model of gram-negative bacteria (Escherichia coli), fungi (Trichoderma harzianum) and related enteroviruses (Poliovirus and Coxsackie). All tested materials showed 59% or more growth inhibition of E. coli. Growth of T. harzianum was inhibited by 16% in the presence of AgTiB2 50W, and other materials caused 37% to 68% inhibition. Enteroviruses infection was completely inhibited after 1 hour of AgNPs treatment. Only Coxsackie A7 retained infection capability after 30 minutes of treatment with AgNPs. Moreover, the ICP-OES-measured amounts of silver released in cultivation media are lower than most published studies of silver nanoparticles with a comparable antimicrobial effect. Keeping silver concentration at the lowest possible limit is one of the most critical factors for producing environmentally safe antimicrobial materials for everyday use.