US Patent 7318908 - Multi-chemical carbon nanotube sensor

http://www.freepatentsonline.com/7318908.html

This patent from Stanford has priority going back to 2001 and includes basic claims to carbon nanotube chemical sensors that are functionalized to detect more than one chemical. Claim 1 reads:

1. A molecular sensor comprising a plurality of carbon nanotubes including: a first carbon nanotube having a first composition and adapted for detecting a first molecular species; and a second carbon nanotube having a second composition and adapted for detecting a second molecular species, the first composition being different from the second composition.