my recent articles |
| Bug-popping nanotubes promise clean surfaces |
|
22 August 2007, for New Scientist Coating surfaces with carbon nanotubes could keep them microbe-free, according to a study that shows how they pop and kill bacteria upon contact. Several previous studies have shown that carbon nanotubes can be toxic to human cells in the lab, and to some animals, although results have sometimes conflicted and often been controversial. However, until now no-one had checked to see if carbon nanotubes could kill microbes. "We thought, why not see if we can use this toxic effect in a beneficial way," says Menachem Elimelech of Yale University, who led the new study.Elimelech and colleagues tested single-walled carbon nanotubes, the simplest kind of nanoscopic roll-up carbon. The nanotubes were each about 1 nanometre across – a small fraction of the size of a bacterial cell. Purified tubesEarlier studies looking at the toxicity of nanotubes often used ones that had not been cleaned properly beforehand, Elimlech says, which may explain why results often conflicted. Elimelech's team cleaned their nanotubes extensively to get rid of nearly all impurities, such as toxic metals left over as by-products of manufacturing. This way they could properly study the effects of the nanotubes alone. They presented the results at the American Chemical Society meeting in Boston, US, on 20 August 2007. Read the rest of the article on New Scientist's website. |