Biosynthesized Silver Nanoparticles for Antibacterial Treatment of Cellulosic Fabrics Using O ₂ -Plasma

A silver-tolerant (3.5 mM silver nitrate) marine bacterial isolate ( Bacillus sp.) was used for biosynthesis of Ag-nanoparticles. UV-Vis spectra showed an absorption peak between 410 and 440 nm. Transmittance electron microscopic (TEM) analysis indicated the presence of 2 to 7 nm Ag-nanoparticles. O ₂ -plasma pretreatment, followed by subsequent treatment with biosynthesized Ag-nanoparticles, improved loading and fixation onto the activated surfaces of the cellulosic fabrics (linen, cotton, and lyocell), and improved antibacterial activities against Gram-positive ( Staphylococcus aureus) and Gram-negative ( Escherichia coli) bacteria. Presence of Ag-nanoparticles on linen and lyocell surfaces was confirmed using scanning electron microscope (SEM) images. Antibacterial activity showed no severe reduction even after 15 washing cycles. Surface modification extent, Ag-nanoparticle loading, as well as antibacterial activity, was determined by the nature of cellulosic substrate.