Classical molecular dynamics was used to investigate the mass-sensing potential of graphene monolayers, using gold as the model adsorbed atom. Firstly, it was found that while perfect graphene monolayers were effective mass sensors at very low (T < 10K) temperatures, their mass-sensing capability was lost at higher temperatures due to diffusion of the adsorbed atom at elevated temperatures. It was demonstrated that even if the quality-factors were significantly elevated through the application of tensile mechanical strain, the mass sensing resolution was still lost at elevated temperatures, which demonstrated that high quality-factors alone were insufficient to ensure the mass sensing capability of graphene. Second, it was found that while the introduction of single vacancies into the graphene monolayer prevents the diffusion of the adsorbed atom, the mass sensing resolution was still lost at higher temperatures, again due to quality-factor degradation. Finally, it was demonstrated that, if the quality-factors of the graphene monolayers with single vacancies were kept acceptably high through the application of tensile strain, then the high quality-factors, in conjunction with the single atom vacancies stopped the diffusion of the adsorbed atom, enabling graphene to maintain its mass sensing capability across a range of technologically relevant operating temperatures.

On the Utility of Vacancies and Tensile Strain-Induced Quality Factor Enhancement for Mass Sensing Using Graphene Monolayers. S.Y.Kim, H.S.Park: Nanotechnology, 2010, 21[10], 105710