Single-particle detection with micro-/nanocantilevers based sensors

摘要

We present a theoretical analysis of micro-/nanocantilever based sensors for detection of a particle in vacuum and in viscous fluid. Ultra-high sensitivity detection in fluid will provide better understanding of realistic behavior of molecules and biomolecules in a native environment. We derive simple expressions for the resonant frequency shift accounting for an attached mass in vacuum and viscous fluid. We show that by detecting the first flexural and torsional modes of the cylindrical cantilever (e.g. carbon nanotube or nanowire) the attached mass and position can be accurately resolved. For other cantilever geometries (i.e. rectangular shape, V-shape, etc.) two flexural and torsional modes are needed to determine the mass and the position of the attached particle.