Sep 16, 2008
Nanoprobes encourage liquid to reveal all
Yury Gogotsi and his colleagues at Drexel University, US, have shown that dispersing carbon nanotubes in a liquid allows the simultaneous chemical analysis of multiple dissolved elements within nanoseconds. The sharp-tipped particles behave as nanoscale corona discharge probes in the presence of an electric field and yield highly sensitive optical emission spectra.
"Chemical analysis will be the first application to take off, but the discharge could also be used to pattern surfaces or synthesize nanoparticles," Gogotsi told nanotechweb.org.
To perform the measurement, the researchers apply a pulsed voltage to the liquid sample under test. A low-power generator, which can fit in the palm of a hand, is sufficient to induce a nonthermal plasma around the dispersed carbon nanotubes. Light from the discharge is collected by a single optical fibre that is aligned with the emission event and connected to a spectrometer, which separates the signal into individual peaks (see image).
The group plans to develop a portable version of its apparatus and is busy scaling down the size of its current set-up. "We are looking for potential sponsors," he revealed. "We have filed for a patent and will be exploring opportunities for commercialization."
Gogotsi speculates that remotely induced higher-intensity discharges could one day be used to perform nanoscale cell surgery. The idea requires verification, but nanotubes have been shown to penetrate cell membranes. Nanotubes can also make their way to tumour sites following the addition of antibodies.
The researchers presented their work in Angewandte Chemie.
About the author
James Tyrrell is editor of nanotechweb.org.