Carbon nanotube oscillators toward zeptogram detection

We demonstrate an application of a nanotube cantilever for zeptogram-level mass detection. This letter presents a quantitative method to measure the oscillation amplitude of a nanotube cantilever using a focused electron beam of a scanning electron microscope. The quality factor of ∼1000 for the nanotube cantilever is revealed and the resolution of the resonant frequency is achieved to be ∼10Hz, which corresponds to a mass range of less than 100zg at room temperature.