Development of Antimicrobial ZnO Nano-Spine Thin Film on Commercial Air Filter

COVID-19 is a disease caused by the novel coronavirus SARS-CoV-2. According to the U.S. Centers for Disease Control and Prevention (CDC), SARS-CoV-2 is transmitted by exposure to infectious respiratory fluids caused by infected individuals talking, coughing, or sneezing, thus, spreading the virions in airborne droplets (∼370 virions in 1 μm and ∼360,000 virions in 10 μm) and in aerosol forms, which are called 'bioaerosols'. Bioaerosols are one of the particulate matters (PMs) carrying living organisms from biological sources which include fungi, bacteria, and viruses. To reduce the exposure of biological PMs in indoor air condition, an air filter could be applied in air conditioning system in order to collect the bioaerosols on the surface of the filter membrane. However, previous studies report that viruses remain infectious on various surfaces such as polymeric fibrous filters for a few days. That triggered a tremendous effort to develop antimicrobial fiber-based filters for prevention of infectious virus transmission by fomites. Herein, we present antimicrobial thin film of zinc oxide (ZnO) nano-spines on commecial fiber-based filters and its potential for infection prevention. By developing a novel technique of dry aerosol coating process, (Zn) nano-seed was well-covered on the commercial filter fiber. After hydrothermal treatment, high aspect-ratio ZnO nano-spines were densely exhibited on the filter surface, which have significant antimicrobial effect to airborne pathogens due to. their spiky morphology. This novel thin film hold potential for airborne microbial disinfection, and the design of microbicidal materials with wide applicability to commercial air filter.