Not only do bees play a vital role in agriculture by pollinating plants, but it now turns out that they may help keep us from getting blown up. Researchers from the Massachusetts Institute of Technology (MIT) have shown that bombolitins, which are protein fragments found in bee venom, can be used to detect single molecules of nitro-aromatic explosives such as TNT. If used in sensors at locations such as airports, those sensors would be much more sensitive than those currently in use.
The MIT team started by coating the insides of carbon nanotubes with bombolitins. Then, they exposed those nanotubes to air drawn from the vicinity of various explosives. While carbon nanotubes naturally fluoresce, the wavelength of that fluoresced light changes when molecules of nitro-aromatic compounds bind with the bee-venom proteins. Although not visible to the naked eye, this shift in wavelength can be detected by a special microscope – which is what happened in the lab tests.
In the past, MIT has developed similar sensors in which the fluorescent light increased in intensity when explosives were present. Such technology is said to be more error-prone than observing changes in that light's wavelength, however, because readings of intensity can be influenced by ambient light.
By combining different types of carbon nanotubes with different bombolitins, the team have even been able to identify different varieties of explosives. The system can also detect molecules that are created when explosives such as TNT begin to decompose.
Currently, commercial explosives sensors analyze airborne charged particles using spectrometry. While inexpensive and durable, such sensors cannot detect explosives down to the single molecule level. Not only is the bee-venom system capable of doing so, but it works at room temperature and atmospheric pressure.
The technology is being patented, with commercial and military parties already showing interest.