A breakthrough nanotech material has two properties that will appeal to forces facing IED bombers as well as airport security types: It rapidly changes color if exposed to peroxide-based explosives (like the shoe bomber had) and can actually neutralize them too.
The invention has been perfected by Allen Apblett of Oklahoma State University, and its uses are "anywhere terrorist explosives are used, including battlefields, airports and subways," according to Apblett. The system is capable of detecting minuscule amounts of peroxide-based bomb chemicals, which would've been handy in the infamous case of the airline shoebomber Richard Reid, who tried to ignite a peroxide-based explosive concealed in the sole of his sneakers. Peroxide-based bombs are relatively cheap and easy to construct, and the chemicals are pretty readily available--making them very dangerous.
Apblett's system uses an "ink" made of nanoparticles that include a compound of molybdenum, a heavy silvery metal that's used industrially in high-pressure, high-temperature reactions as a catalyst. The sensing ink actually reacts in the presence of peroxides, changing color from dark blue to pale yellow or clear--a vapor of TATP (Reid's bomb chemical) at a concentration of just 50 parts per million turns the ink to yellow inside just 30 seconds. Better yet, the electrical conductivity of the material changes when it senses a danger, meaning it could be built into automatic sensing systems. Apblett suggests the chemistry is so useful it could even be engineered into jewelry (though we're not sure why) and cell phones (with a utility we can more easily imagine).
Even more interesting is the fact the ink can actually neutralize peroxide-based bombs, so it could be kept in vats at high-risk points for security forces to dump newly detected bombs into to immediately quell the risk of an explosion. Right about now you're imagining those vats of purple liquid used to neutralize dangerous objects in Warehouse 13 aren't you? Yeah, us too.