The antimicrobial effect of silicon nanowires decorated with silver and copper nanoparticles

Abstract

The paper reports on the preparation and antibacterial activity of silicon nanowire (SiNW) substrates coated with Ag or Cu nanoparticles (NPs) against Escherichia coli (E. coli) bacteria. The substrates are easily prepared using the metal-assisted chemical etching of crystalline silicon in hydrofluoric acid/silver nitrate (HF/AgNO3) aqueous solution. Decoration of the SiNWs with metal NPs is achieved by simple immersion in HF aqueous solutions containing silver or copper salts. The SiNWs coated with Ag NPs are biocompatible with human lung adenocarcinoma epithelial cell line A549 while possessing strong antibacterial properties to E. coli. In contrast, the SiNWs decorated with Cu NPs showed higher cytotoxicity and slightly lower antibacterial activity. Moreover, it was also observed that leakage of sugars and proteins from the cell wall of E. coli in interaction with SiNWs decorated with Ag NPs is higher compared to SiNWs modified with Cu NPs.

All-nanocellulose nonvolatile resistive memory

“…Before the disposal, the Ag electrode should be removed from the device because Ag has an antibacterial effect 39,40 that suppresses the fungus-based biodegradation of the nanopaper in the natural environment. We found that the removal of the Ag electrode can be achieved by simply applying sonication in water (details are discussed in Supplementary Information S6).…”

H2 sensing properties of modified silicon nanowires

“…Moreover, this process is simple in operation, reliable and inexpensive [11]. The silicon samples are immerged into metal-salt solutions containing HF, and various kinds of metals can be deposited [12][13][14][15].…”

A review of the ecotoxicological effects of nanowires

“…Wang et al (2011) confirmed that Si NW arrays modified with quaternized poly (2-(dimethylamino ethyl) methacrylate) (pDMA-EMA) led to high bacterial adhesion and cell death of E. coli after an 18-h exposure. Fellahi et al (2013) reported that Si NW arrays decorated with AgNPs or CuNPs showed antibacterial activity after a 24-h exposure and induced leakage of sugars and proteins from the cell membranes of bacteria, reducing cell viability. Li et al (2014) observed antibacterial effects of Si NW arrays on E. coli, B. subtilis, and S. aureus.…”

“…Nanowires have potential applications in the biomedical and clinical industries (Brammer et al 2009;Johansson et al 2010;Nataraj et al 2014;Singh et al 2013), as antibacterial agents (Fellahi et al 2013;Holtz et al 2010Holtz et al , 2012Wu et al 2011), as sensors of metals (Luo et al 2009;Mu et al 2007), in solar cells (Garnett and Yang 2010;Hamilton et al 2009), in the removal of metals (Jia et al 2013;Youssef and Malhat 2014), and in energy storage (Chen et al 2009;Tiwari et al 2012).…”