Could humans recognize odor by phonon assisted tunneling?

Phys Rev Lett. 2007 Jan 19;98(3):038101. doi: 10.1103/PhysRevLett.98.038101. Epub 2007 Jan 16.


Our sense of smell relies on sensitive, selective atomic-scale processes that occur when a scent molecule meets specific receptors in the nose. The physical mechanisms of detection are unclear: odorant shape and size are important, but experiment shows them insufficient. One novel proposal suggests receptors are actuated by inelastic electron tunneling from a donor to an acceptor mediated by the odorant, and provides critical discrimination. We test the physical viability of this mechanism using a simple but general model. With parameter values appropriate for biomolecular systems, we find the proposal consistent both with the underlying physics and with observed features of smell. This mechanism suggests a distinct paradigm for selective molecular interactions at receptors (the swipe card model): recognition and actuation involve size and shape, but also exploit other processes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electrons
  • Humans
  • Models, Biological*
  • Models, Chemical
  • Odorants*
  • Receptors, Odorant / chemistry
  • Receptors, Odorant / metabolism
  • Receptors, Odorant / physiology*
  • Smell / physiology*
  • Structure-Activity Relationship


  • Receptors, Odorant