Nano nose sniffs out odour

Nano-sized carbon tubes coated with strands of DNA can create tiny sensors with abilities to detect odours and tastes, according to researchers at the

and

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Their findings are published in the current issue of the journal Nano Letters, a publication of the American Chemical Society.

According to the researchers, arrays of these nanosensors could detect molecules on the order of one part per million. In the report, the researchers tested the nanosensors on five different chemical odourants, including methanol and dinitrotoluene, or DNT, a common chemical that is also frequently a component of military-grade explosives. The nanosensors could sniff molecules out of the air or taste them in a liquid, suggesting applications ranging from domestic security to medical detectors.

"What we have here is a hybrid of two molecules that are extremely sensitive to outside signals: single stranded DNA, which serves as the 'detector,' and a carbon nanotube, which functions as 'transmitter,'" said A. T. Charlie Johnson, associate professor in Penn's Department of Physics and Astronomy. "Put the two together and they become an extremely versatile type of sensor, capable of finding tiny amounts of a specific molecule."