▎ 摘　　要

The high frequency and ultrasmall mass of graphene make it an ideal material for ultrasensitive mass sensing. In this article, based on the all-optical technique, we propose a scheme of an optical mass sensor to weigh the mass of a single atom or molecule via a doubly clamped Z-shaped graphene nanoribbon (GNR). We use the detection of shifts in the resonance frequency of the Z-shaped GNR to determine the mass of an external particle landing on the GNR. The highly sensitive mass sensor proposed here can weigh particles down to the yoctogram and may eventually be enable to realize the mass measurement of nucleons. (C) 2013 Optical Society of America