Detection of Ordered Molecules Adsorbed on Graphene: a Theoretical Study

Graphene has been demonstrated to be able to detect individual gas molecules Schedin et al. Nat. Mater. 6 (2007) 652, which has attracted a lot of sensor research activities. Here we report for the first time that graphene is capable of detecting the ordering degree of absorbed water molecules. The efficiency of doping varies from the degrees of molecular ordering. The simulated results show that the highly ordered water molecules contribute more to the doping effect, which reduces the conductance of the water/graphene system.