Optics, Photonics & Lasers

Biography

Biography: Andrey Ionin

Abstract

Antibacterial coatings were fabricated by laser ablation of silicon in liquid media. Laser radiation (λ=1030 nm,τ=10 ps, E=10 μJ) was focused onto the Si wafer under the 5-mm layer of liquid carbon disulfi de (CS2) and raster-scanned across the surface. The resulting laser-induced morphology consisted of nanosheets (NS) with high height-to-width ratio, and its antibacterial properties were tested on S. aureus strain. Th e S. aureus strain was grown in a nutrient medium and incubated for 24 h at 37°C on the surface of Si NS, smooth Si wafer and silica glass as a control. Their staining with “Live/Dead Biofi lm Viability Kit” allowed assuming, that no any biofilm was formed onthe Si NS, unlike smooth Si and silica glass. The bacterial death was possibly caused by the mechanical damage of the cell membrane on the sharp edges of Si NS, or its possible chemical activity. Another type of antibacterial coating was fabricated by placing Si nanoparticles (NPs) on a smooth Si wafer. NPs were prepared by laser ablation (λ=1064 nm,τ=120 ns, E=0.1 mJ) of silicon plate under the 3-mm layer of either isopropanol or deionized water. Th e resulting Si NP colloidal solutions were air-dried, and their antibacterial activity and hydrophobic properties were tested using S. aureus and P. aeruginosa.