A research team at Stanford has developed a new inexpensive sensor chip made with carbon nanotubes, being capable to detect rapid traces of TNT and poison in rivers, reservoirs. This sensor could be used to detect other kinds of toxins and help us track down polluters and it also can be useful to detect terrorist attacks on the water supply or leaching from ammunition making or storage facilities.
“We have used semiconducting carbon nanotube network transistors to make extremely sensitive sensors that are capable of operating stably under water,” Bao said. “We showed sensitivity in the range of a few parts per billion for detection of explosive compounds such as TNT.”
The most amazing thing with these nanotube sensors is that they are much more sensitive than what we currently have because they are built using processes developed in Bao’s lab that ensure a high-density of well-aligned nanotubes that are almost purely semiconducting. This chip is made of a flexible, inexpensive substrate, rather than the more expensive, rigid silicon that underlies most computer chips. The scientists have used a thin polymer gate electrical insulator layer, allowing the device to operate on less than 1 volt of electric energy.