A novel instrument capable of detecting single molecules of explosives such as TNT has been built using carbon nanotubes and, strangely, bee venom proteins.
The detector draws upon the discovery that carbon nanotubes emit a specific spectrum of infra-red light depending on the chemical environment.
Carbon nanotubes, by themselves, are not able to detect TNT. When coated with a protein derived from bumble bee venom known as bomboliti, however, the nanotubes became sensitive to the TNT molecules. TNT alters the 3D structure of the bomboliti protein, which in turn cause the nanotubes to emit a characteristic fingerprint of infra-red light that can be identified by the new detector.
Using different proteins, the team from MIT were able to create detectors for other compounds including RDX, an explosive implicated in both the 2006 Mumbai and the 2010 Moscow terrorist attacks.
Current detectors, although reliable, are not able to sense the explosive chemicals unless in significant quantities. The new technology is so sensitive it can detect even single molecules -“the ultimate detection limit”, as Michael Strano, lead author of the paper, says. The new sensors also have the advantage of being able to detect the presence of related chemicals that TNT can transform into over time.