Carbon nanotubes could hold the key to chemical weapons detection, claim US navy scientists.

Eric Snow of the Naval Research Laboratory, Washington DC, US, suggests that using 2D networks of carbon nanotubes could overcome the problems that have blocked their use in sensors.

Carbon nanotubes have been the topic of much research over the years, including in chemical sensing. However, there are a number of problems which have blocked making a practical sensor. These include the difficulty in making reliably uniform nanotubes and the presence of high levels of noise in the signal. 

Snow believes that single-walled carbon nanotubes are promising for detecting chemical vapours, as molecules adsorbed on the surface can significantly alter the nanotube's electronic properties. Snow made 2D networks that are shown to average the individual properties of the nanotubes. These networks can be made to a high yield using existing techniques. In addition, the networks can reduce the low frequency noise which is a significant problem in chemical detection, which are normally performed at such frequencies.

Li Jiang from Schlumberger-Doll Research is enthusiastic about the work. He said the technique is 'of considerable potential significance: the application of single wall carbon nanotubes as chemical sensors represents far reaching opportunities for practitioners in the areas of materials, biological and environmental science.'

Snow explained why he has focused in this area. 'Events over the past several years have placed an increased emphasis in the Department of Defense on the development of enhanced sensor technology,' said Snow. 

Hoping that the technique will soon be ready for use, Snow said that in the future 'the areas of application will be determined by the imagination and creativity of scientists and engineers.'

Laura E Howes