Silver is toxic to bacteria, and nanoparticles of the element offer promise as a coating for medical devices. But silver nanoparticles readily oxidize and clump together, losing their antibacterial activity.

Qing Huang and Chunhai Fan of the Chinese Academy of Sciences in Shanghai, Shuit-Tong Lee of City University of Hong Kong, and his colleagues solved this problem by growing the particles on biocompatible silicon nanowires. This avoids the need for toxic or expensive chemicals to stabilize the silver nanoparticles.

The researchers show that exposure to a 10% solution of silver-coated nanowires froze population size in the bacteria Escherichia coli and Bacillus subtilis throughout a two-day test period.

The main findings have been published in Advanced Materials, 2010, Adv Mater., 22, 48: 5463-5467. (Source: Nature.com)