Single molecule enzymology using carbon nanotube circuits

For over a decade, researchers have pursued sensitive, label-free biosensing and biodetection using nanoscale electronic devices like field-effect transistors. Prototype devices made with single-walled carbon nanotubes proved to have enough sensitivity to detect single molecule events, as well as sufficient bandwidth to monitor real time dynamics. Combining these characteristics has led to novel electronic measurements where the bond-by-bond chemical activity of single enzyme molecules is monitored in real time. The high bandwidth of the nanotube transistors allow every individual chemical event to be clearly resolved, providing excellent statistics from tens of thousands of turnovers by a single molecule.