  The difficulty in determining the mass of a sample increases as its size
diminishes. At the nanoscale, there are no direct methods for resolving the
mass of single molecules or nanoparticles and so more sophisticated approaches
based on electromechanical phenomena are required. More importantly, one
demands that such nanoelectromechanical techniques could provide not only
information about the mass of the target molecules but also about their
geometrical properties. In this sense, we report a theoretical study that
illustrates in detail how graphene membranes can operate as
nanoelectromechanical mass-sensor devices. Wide graphene sheets were exposed to
different types and amounts of molecules and molecular dynamic simulations were
employed to treat these doping processes statistically. We demonstrate that the
mass variation effect and information about the graphene-molecule interactions
can be inferred through dynamical response functions. Our results confirm the
potential use of graphene as mass detector devices with remarkable precision in
estimating variations in mass at molecular scale and other physical properties
of the dopants.
