Departments of Physics and Electrical and Computer Engineering, and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801.
Proc Natl Acad Sci U S A. 2013 Oct 15;110(42):16748-53. doi: 10.1073/pnas.1308885110. Epub 2013 Sep 30.
By using the nonequilibrium Green's function technique, we show that the shape of the edge, the carrier concentration, and the position and size of a nanopore in graphene nanoribbons can strongly affect its electronic conductance as well as its sensitivity to external charges. This technique, combined with a self-consistent Poisson-Boltzmann formalism to account for ion charge screening in solution, is able to detect the rotational and positional conformation of a DNA strand inside the nanopore. In particular, we show that a graphene membrane with quantum point contact geometry exhibits greater electrical sensitivity than a uniform armchair geometry provided that the carrier concentration is tuned to enhance charge detection. We propose a membrane design that contains an electrical gate in a configuration similar to a field-effect transistor for a graphene-based DNA sensing device.
利用非平衡格林函数技术，我们表明边缘的形状、载流子浓度以及石墨烯纳米带中纳米孔的位置和大小会强烈影响其电子电导以及对外部电荷的敏感性。该技术与自洽的泊松-玻尔兹曼形式相结合，可用于检测纳米孔内 DNA 链的旋转和位置构象。具体来说，我们表明，具有量子点接触几何形状的石墨烯膜比均匀扶手椅几何形状具有更高的电敏感性，前提是载流子浓度被调谐以增强电荷检测。我们提出了一种膜设计，其中包含类似于场效应晶体管的电门，用于基于石墨烯的 DNA 传感装置。
