New Bomb Detector Sniffs Out TNT One Molecule at a Time
CREDIT: Blue Funnies, via Flickr.
Tiny bomb detectors that could sniff out a single molecule of the main ingredient in the explosive TNT could be the next in airport security. The new chemical sensor is made out of tiny cylinders of carbon coated with bombolitins, which are chemicals found in bee venom. It turns out that these venom substances can pick out TNT-like explosives from a lineup of other chemicals.
"What we've shown that's interesting is first we found that there's a peptide in bee venom that can actually recognize a whole class of nitro-aromatic compounds," said study team member Michael Strano, a professor of chemical engineering at MIT. "The other thing that we showed was that you can actually get the system to respond to the binding of just one explosive molecule ."
Carbon nanotubes are thin sheets of carbon rolled up into tiny tubes that each have a diameter about 30,000 times smaller than the width of a strand of hair.
There's "some additional work that needs to be done" before this sensor makes its way into airport terminals, Strano told InnovationNewsDaily. But this isn't far off, and could happen as soon as four to five years from now, Strano said.
Devices used today to detect explosives in places such as airports can detect down to the parts per trillion level, which is the equivalent of about a billion molecules , Strano said. Typically, these sensors use what's called ion-mobility spectrometry.
This new sensor relies on an inherent property of carbon nanotubes, which causes them to fluoresce red infrared light. Fluorescence is the property of some materials whereby they absorb light and re-emit it in a different color.
When TNT-like molecules bind to the venom peptide, they cause the carbon nanotubes to fluoresce in a different color, thus signaling that an explosive has been detected.
Strano and his colleagues detail their findings May 9 in the Proceedings of the National Academy of Sciences.