Researchers at Rice University successfully utilized a near-infrared flourescent imaging technique to detect individual carbon nanotubes in fruit flies. The study, reported here and here, involved an experiment where the researchers fed fruit fly larvae a diet that contained carbon nanotubes. The flies were then shot with a laser, which excited the nanotubes and allowed them to be viewed using a flourescent technique. The good news is that the fruit flies apparently survived to adulthood just as well as fruit flies in the control group, and apparently weighed the same as the controls, too. The study’s conclusions about the bioaccumulation of the nanotubes in the fruit flies are interesting:
When the researchers removed and examined tissues from the flies, they found the near-infrared microscope allowed them to see and identify individual nanotubes inside the tissue specimens. The highest concentration of nanotubes was found in the dorsal vessel, which is analogous to a main blood vessel in a mammal. Lesser concentrations were found in the brain, ventral nerve cord, salivary glands, trachea and fat. Based on their assays, the team estimates that only about one in 100 million nanotubes passed through the gut wall and became incorporated into the flies’ organs.
I don’t know enough about the anatomy of a fruit fly to fully grasp the significance of these findings, but I find it hopeful that only a tiny fraction of the nanotubes accumulated in the flies’ organs, and also find it hopeful that the flies were apparently not harmed by the nanotubes’ presence. One of the researchers quoted in the report, Dr. Bruce Weisman, is a well-known nanotechnology researcher at Rice.
Thanks to Youtube, we can see a six second video of the carbon nanotubes "lit up" inside the fruit flies here.