Los Alamos National Laboratory has built an improved dog nose out of molecular buckets.

Why?

To sniff out chemical and biological weapons, land mines and even diseases such as cancer, said Basil Swanson and Karen Grace, the two scientists who designed it.

"This system is about two orders of magnitude more sensitive than other types of detectors," Swanson said. "That's important because land mines, chemical and biological agents don't give off a lot of substance to let us know they're there."

The system uses molecular buckets to create a synthetic sense of smell. They are actually microscopic containers designed to specifically trap certain types of contaminants - and they put the world-renowned sensitivity of a dog's nose to shame, the scientists say.

"These little buckets trap certain odors, which like to go in and hang out inside of them," Swanson said. "We make different films out of the buckets and can tailor their properties. It's sort of like fitting a peg in a hole, but we're catering the surface to detect smells."

Two light beams then shine through the system - one goes through the buckets and one works as a baseline - and scientists can tell by changes in those light patterns how much and what type of contaminant is present, Grace said.

The labs recently completed several patents on the technology and have several more pending, the two scientists said.

The system was designed to test for land mines, which put out trace amounts of TNT into the air above them.

"There's a couple ways to remove land mines," Swanson said. "You can get a big honking vehicle and run over them, but that's hard to do in places like Cambodia, where there are significant land mine problems, or you can use a metal detector, which gives you a lot of false-positives."

Dogs and even bees have also been used to detect land mines by their scent, but this technology could work more effectively because it doesn't get tired after a few hours of work, and the sensors are reusable, the scientists said.

"What you really want to do to find these things are mimic a dog's nose, make it more sensitive and train it so it doesn't get false-positives," Swanson said.

The scientists are altering the technology to make low-maintenance air sensors that can be placed around cities, and work for a year before parts need replacing. The sensors would look for biological or chemical terrorism attacks - such as sarin gas, anthrax or smallpox - and would set off an alarm if any of those substances were detected.

"The technology also has to be geared so it doesn't pick up things you don't want," Grace said. "That's a high level of sensitivity. The elements we're looking for are in very limited amounts and very specific, so tailoring the device is a challenge."

They envision a system that could be attached remotely to a computer so officials could monitor it daily, the scientists said.

That technology is realistically about four or five years off, but the research is fully funded because of homeland security applications, they said.