title: Dynamical response of nanomechanical oscillators in immiscible viscous fluid for in vitro biomolecular recognition.
abstract: Dynamical response of nanomechanical cantilever structures immersed in a viscous fluid is important to in vitro single-molecule force spectroscopy, biomolecular recognition of disease-specific proteins, and the study of microscopic protein dynamics. Here we study the stochastic response of biofunctionalized nanomechanical cantilever beams in a viscous fluid. Using the fluctuation-dissipation theorem we derive an exact expression for the spectral density of displacement and a linear approximation for resonance frequency shift. We find that in a viscous solution the frequency shift of the nanoscale cantilever is determined by surface stress generated by biomolecular interaction with negligible contributions from mass loading due to the biomolecules.
authors.affiliation: Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, USA.
authors.forename: Jerome
authors.initials: J
authors.lastname: Dorignac
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Kalinowski
authors.forename: Shyamsunder
authors.initials: S
authors.lastname: Erramilli
authors.forename: Pritiraj
authors.initials: P
authors.lastname: Mohanty