Graphene resembles a single layer of graphite. It is being explored as a potential sensor material, among other applications, because each carbon atom is effectively a surface atom exposed to gaseous analytes.

US researchers have exploited this property to build a transistor device based on a graphene material that operates under a positive gate potential. The device gives an instantaneous response on exposure to ammonia gas and is far superior to devices that work with a negative gate potential. The device behavior is reproducible and amenable to real-world gas-sensing applications.

• Ultrafast room temperature NH₃ sensing with positively gated reduced graphene oxide field-effect transistors
  G. Lu, K. Yu, L. E. Ocola, J. Chen,
  Chem. Commun. 2011.
  DOI: 10.1039/C1CC12658J