Stanford researchers develop smell technology

January 27, 2011 7:49:05 PM PST
A research team at Stanford is working on a technology that might be compared to the human nose. Its goal is to detect and identify substances, almost by sense of smell.

The average human nose can distinguish between about 200 scents and now researchers are attempting to duplicate that sensitivity in a machine.

"So, for example, when we smell things, it's multiple... molecules will interact with multiple receptors, so we're kind of doing the same thing with our DNA," says Stanford University professor Eric Kool, Ph.D.

In his lab at Stanford, Kool and his team are manufacturing synthetic DNA. But instead of controlling functions in the human body, their DNA is engineered to react to compounds in the environment.

"We want to be able to smell contaminates in the air, for example, in environmental applications, we'd like to be able to taste toxins in the water," says Kool.

To accomplish that, they replaced certain molecules of the DNA with fluorescent compounds, seven colors in all. Then they exposed their newly created DNA sensors to vapors injected into a vial. The result was the tiny beads of DNA turned different colors, depending on the vapor they were reacting to.

And with thousands of possible DNA combinations, research assistant C.K. Koo, Ph.D., believes the technology could at least start to approach the complexity of human smell.

"It is pretty similar because we use set of sensors, not just one. A library of sensors to differentiate different gasses, it's just like a nose," says Koo.

They're hoping to use the DNA sensors to power inexpensive fluorescent microscopes, like one ABC7 profiled last year. It was crafted from an iPhone by a group at the University of California.

"So the idea is we could sense a hundred different things with 10 different sensors by reading a pattern of responses," says Kool.

It's a high-tech nose is not meant to replace human smell, but simply mimic it.

The team is already in contact with makers of the portable fluorescent microscope about possibly merging the technologies in the future.