Single crystalline copper oxide nanoribbons were synthesized via a surfactant-assisted hydrothermal
route. The resulting CuO nanoribbons contain substantial amounts of nanorings and nanoloops. High
resolution TEM analysis identified CuO nanoribbons growing along the  direction. CuO
nanoribbons exhibited excellent sensing performance towards formaldehyde and ethanol vapours with
rapid response and high sensitivity at low operating temperatures. We found that the loading of a small
amount of Au or Pt nanoparticles on the surface of CuO nanoribbons can effectively enhance and
functionalize the gas sensing performance of CuO nanoribbons.