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 similar to 1000 for the nanotube cantilever is revealed and the resolution of the resonant frequency is achieved to be similar to 10 Hz, which corresponds to a mass range of less than 100 zg at room temperature. (C) 2005 American Institute of Physics.