Catalyst Droplet-Based Puncturable Nanostructures with Mechano-Bactericidal Properties Against Bioaerosols

摘要

Bioaerosol contamination problems have led to the need for new technologiesthat effectively collect and inactivate airborne microorganisms. Typicalnanomaterial-based filter membranes are usually sterilized using photocatalysts,electrical stimulation, and thermal treatment, which are expensiveand require additional devices and cumbersome manufacturing. In thisstudy, a membrane with nanotopographical features is manufactured via acatalyst droplet-based procedure to mechanically damage airborne bacteria.The catalyst droplets are used as templates for in situ novel puncturablenanopillar growth on the membrane surface. Numerical simulations andmicroscopic observations show that puncturable nanopillars with a thin andrough nano-edge are advantageous for rupturing the bacterial cell comparedto flat nanopillars without a thin edge. A puncturable nanostructuredair filter (PNAF) is compared to a bare air filter and exhibits higher bioaerosolcollection efficiencies (>98 and 89.3–95.7, respectively). PNAFis tested under breathing conditions as part of a face mask, where iteffectively captures and deactivates E. coli aerosols through a mechanobactericidaleffect, resulting in the inhibition of bacterial proliferation andfinally death. Thus, PNAF can be applied as an air purifier or face mask filterfor bioaerosol collection presenting antibacterial effects without externalstimulation.