Nanoparticle-coated silicon nanowires kill bacteria
doi:10.1038/nindia.2013.169 Published online 17 December 2013
Researchers have fabricated nanosized silicon wires embedded with silver and copper nanoparticles that can help kill disease-causing bacteria . These nanowires are very promising for fighting bacterial infections.
To devise a simple and cost-effective technique to produce antibacterial nanoparticles, the researchers synthesized silicon nanowires by simple chemical etching of crystalline silicon using an aqueous solution of hydrofluoric acid and silver nitrate. They then coated the surfaces of these silicon nanowires with silver and copper nanoparticles.
They evaluated the antibacterial activities of the metal-nanoparticle-coated nanowires against Escherichia coli. Nanowires decorated with silver nanoparticles showed higher antibacterial activity than copper-nanoparticle-coated nanowires, killing 94 per cent of bacterial colonies compared with 84 per cent by the copper-nanoparticle-coated nanowires. Increasing the density of the metal nanoparticles on the nanowire surface improved the antibacterial activity.
The silver and copper nanoparticles attached to the surfaces of the nanowires induced bacteria death by accelerating leakage of sugars and proteins through the bacterial membrane. Tests with cervical cancer cells revealed that the nanowires were biocompatible.
The researchers say that besides their therapeutic potential, the metal-nanoparticle-coated nanowires could be used for photodegradation of organic pollutants.