  We investigate the role of quantum effects (e.g. zero-point energy
fluctuations) in the physics of nanotube- and nanowire-based electromechanical
sensors as discussed in a recent article [Postma et al., Appl. Phys. Lett. 86,
223105 (2005)]. Employing the quantum fluctuation-dissipation theorem we find
that these effects pose additional limits on the dynamic range of
nanomechanical resonators.
