Biosynthesis of Silver Nanoparticles on Polypropylene Nonwovens: towards Antimicrobial Protection

The utilization of disposable face masks is an essential approach to mitigate the transmission of microorganisms. Composed mainly of polypropylene (PP) nonwoven material, these masks do not exhibit any antimicrobial properties. This study examines the feasibility of employing Ag-based nanoparticles (NPs) as an antimicrobial agent. To activate the chemically inert PP samples, corona discharge was applied at atmospheric pressure. Subsequently, a sol-gel coating with (3-aminopropyl) triethoxysilane was performed, which introduced amino groups necessary for the absorption of silver ions. The in situ biosynthesis of Ag-based NPs was conducted using extracts from Cannabis sativa L., Cannabaceae, and Paliurus spina-christi Mill., Rhamnaceae. Morphological and chemical changes were evaluated using FESEM, FTIR, and XPS analyses. The antimicrobial activity of the fabricated substrates was tested against the Gram-negative bacterium Escherichia coli, the Gram-positive bacterium Staphylococcus aureus, and the yeast Candida albicans. Cytotoxicity assessments were conducted utilizing HaCaT and MRC5 cell lines. Findings from FESEM and AAS revealed that the size and quantity of the synthesized NPs were influenced by the plant extract used. XPS analysis confirmed the presence of NPs as a mixture of Ag₂O and AgO, which achieved a remarkable bacterial reduction of 99.9% without exhibiting cytotoxic effects.