Those in the artificial nose business dream of the day their products equal or surpass the olfactory repertoire of the real thing. For now, the human nose comes pre-packaged with a wider selection and faster detection of smells than any electronic device.
Neuroscientists at Tufts University School of Medicine who double as officers for the North Andover-based company CogniScent Inc may soon close this gap. Their research, published on PLOS Biology last week, found two new roles for single-stranded DNA: One as the latest in odor-sensing technology and the other as a possible small molecule receptor.
The detector works after attaching a florescent marker (Cy-3) to the end of a DNA strand and drying it onto a solid surface. From there it glows after exposures to various odor molecules. Some used in the experiments were methanol, DNT (previously undetectable by any other device) and propionic acid, all toxic in some way. In the long run this technology will benefit safety inspectors and law enforcement, the most likely customers for electronic noses.
The mechanism for making DNA glow is still not well understood. The researchers guess it is brought on by changes the three-dimension shape caused by binding to the correct odor molecule. It’s been known for a long time that DNA binds molecules in the nucleus, but this research raises the possibility for other receptor-roles in the cell.
From a business perspective DNA is cost-cutters dream. It is cheap and easy to replicate, once you have a DNA sequence that detects the odor you want, simply run it through an assay for more. This also has the potential for mass-production if they can make the detection devices small enough.
Just one cautionary note, while peer-reviewed this research has yet to be replicated and more reporting needs to be done on possible limitations before it is certain this is a true step forward for the field.
White J, Truesdell K, Williams LB, AtKisson MS, Kauer JS (2008) Solid-state, dye-labeled DNA detects volatile compounds in the vapor phase. PLoS Biol 6(1): e9. doi:10.1371/journal.pbio.0060009
For more information, check out “DNA-based Artificial Nose” in Technology Review.