CC BY
20B-O-6
Antibacterial silicon-based laser-fabricated nanocoatings
A. Ionin1, S. Kudryashov1, A. Nastulyavichus1, I. Saraeva1, N. Smirnov1, A. Rudenko1, E. Tolordava2, D. Zayarny1, S. Gonchukov3, Y. Romanova2
1P. N. Lebedev Physics Institute of Russian Academy of Science, Quantum Radiophysics, Moscow, Russian Federation
2N.F. Gamaleya Federal Research Centre of Epidemiology and Microbiology, Laboratory of gene engineering of pathogenic microorganisms, Moscow, Russian Federation 3National Research Nuclear University MEPhI Moscow Engineering Physics Institute, Laser Plasma, Moscow, Russian Federation
Antibacterial coatings were fabricated by laser ablation of silicon in liquid media. Laser radiation (1030 nm, 10 ps, 10 J was focused on the Si wafer under the 5-mm layer of liquid carbon disulfide (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. Fig.1. demonstrates SEM image of Si NS with S. aureus biofilm (a), optical images of bacteria, stained with fluorescent dye (b) - dead and alive on the smooth Si wafer (c) and on the silica glass (d).
The 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 Biofilm Viability Kit" allowed assuming, that no any biofilm was formed on the 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 (1064nm, 120ns, 0.1mJ) of silicon plate under the 3-mm layer of either isopropanol or deionized water. Fig.2. demonstrates angles and optical images of alive (green) and dead (red) bacteria on the surface of smooth Si wafer (a, d, g), wafer with Si NPs, prepared in isopropanol (b, e, h) and in deionized water (c, f, i). The resulting Si NP colloidal solutions were air-dried, and their antibacterial activity and hydrophobic properties were tested using S. aureus and P. aeruginosa.
The research was supported by the Russian Science Foundation (Project #18-15-00220).
