Researchers develop nanotube material to detect threats

A team of researchers from Lawrence Livermore National Laboratory and the Swiss Federal Institute of Technology recently announced a way to use nanotubes to detect trace amounts of biological threats, explosives and drugs.

The joint research team used long, thin carbon nanotubes coated with gold-hafnium to increase detection in surface-enhanced Raman spectroscopy. SERS enables researchers to see photons scattered by molecules held in a thin film on rough metal surfaces or nanostructures.

Metal-coated nanotubes placed in a canopy-like arrangement enhance light by trapping incident light and allowing Raman-scattered light to pass through. The team discovered using hafnium as a coating blocked the suppression of free electrons, and allowed the nanotubes to function uninhibited. By shielding electrons and enhancing light through the nanotubes, the team is able to increase SERS' detection sensitivities, allowing researchers to identify substances present in trace amounts.

The joint research team is led by LLNL engineer Tiziana Bond and ETH scientist Hyung Gyu Park.

"This is a very important discovery in our efforts to improve the use of SERS devices," Bond said. "We gained this valuable knowledge through multidisciplinary basic research and approaching the problem with a rational design."

Bond and Park hope their material will be used in portable devices to conduct on-site analysis of pollutants or pharmaceutical residue in water, as well as rapid screening of drugs and toxins and point-of-care monitoring of physiological levels.