Chemical Engineers at MIT have come up with an ultra-sensitive explosive detector that is capable of detecting even minute traces of explosives.
The research team, which was led by Michael Strano, had built the sensor by coating hollow, single atom thick carbon nanotubes with the protein fragments called bombolitins, which is found in the venom of bees. This protein shows a reaction when exposed to nitro-aromatic compounds like TNT. The sensor would exhibit better sensitivity to explosives when compared to the detectors currently available in the market.
The new sensor technology was published online in Proceedings of the National Academy of Science. Strano is awaiting patent approval for the nanosensor.
For the past few years, Strano and his team have been working on developing carbon-nanotube sensors for detection of a number of molecules such as nitric oxide, toxic nerve gas sarin etc. The principle behind the sensing of molecules is that the sensor takes advantage of the inherent fluorescence of the carbon-nanotubes by binding the molecules to a particular target. The explosive sensor uses a slightly different detection technique in which the wavelength of the fluorescent light gets shifted when the target molecules bind with the bombolitins, without altering its intensity. This shift in the wavelength is seen through a microscope that is specially built for reading the signal.
Strano claims that reading the wavelength is an error and noise free technique. In order to detect different nitro-aromatic compounds, the researchers prepared different nanotubes coated with different bombolitins. They were able to establish a set of distinctive fingerprint for each explosive to be detected. The carbon-nanotubes can detect the breakdown of compounds in such explosives. The sensor is also capable of detecting pesticides that are nitro-aromatic compounds; hence, they find applications in environmental monitoring as well.
Soldier Nanotechnologies at MIT extended financial support for the project.
Source: http://web.mit.edu/