Nano Food: Science Sensei 6

One, clearly, is safety and/or toxicity. But a more basic problem is: If we are going to use such tiny things, like carbon nanotubes, to perform functions inside our bodies, how will we monitor them?

A team of researchers at Rice University has come a step closer to answering that question, by literally feeding carbon nanotubes to one of our tiniest lab specimens, fruit flies.

With funding from the National Science Foundation, chemist Bruce Weisman led the team created a paste that contained carbon nanotubes, and had the flies eat it during the larva stage, when fruit flies are voracious eaters. One special property of nanotubes is that they give off fluorescent light. Using a custom-built microscope equipped with a red laser, the researchers were able to see the near-infrared light given of by the nanotubes inside the flies while they were still alive. As they wrote in the journal Nano Letters (2007, Vol. 7, No. 9), they recorded the first optical images of carbon nanotubes inside a living organism.

This first attempt was a "shotgun approach" where they let the nanotubes go where they may. Incidentally, most ended up in the flies' main blood vessel, but others were found in the brain, ventral nerve cord, salivary glands, trachea and fat. In future experiments, the researchers hope to see if they can control exactly where the nanotubes go.

As for safety question, the flies that dined on nanotube paste survived to adulthood just as well as control flies that ate regular fly fare.