Nano Lett.：具有离子通道活性的半导体膜纳米

    生物谷报道：伊利诺斯州立大学研究人员设计的1种半导体膜能够具有比生物膜更灵活、更好的电性能。采用掺有杂质的硅层，这种固态膜还可用于单分子检测、蛋白过滤和DNA测序。研究结果刊登于Nano Letters杂志。

    文章高级作者Jean-Pierre Leburton 说：“通过在这层膜上制作纳米孔，我们可以用此膜分离带电荷的物种或者调控带电荷的分子流和离子流，从而模仿生物离子通道的运转。”Leburton率领的研究小组在许多静电势下模拟此半导体膜的运转。

    研究模型中，纳米孔-膜结构是由两层硅组成，每层厚12纳米，携带对立的（n和p）半导体杂质。膜的n面是正极，p面是负极。纳米孔是沙漏状，颈部直径为1纳米，在每面开口的直径为6纳米。可以通过改变电势而改变纳米孔的型号。

    通过控制离子流，人造纳米孔提供了生物离子通道所不具备的1定程度的可调性（tunability）。除了可作为生物离子通道的替代品，这种固态纳米孔和膜还有其它用途，比如DNA测序。

    研究人员说：“利用半导体膜技术测序DNA分子，既省时又省钱，通过偏置跨膜电压，我们能够从纳米孔拔出DNA。因为每对碱基都携带的电荷不同，我们可以将这种膜作为p-n 结合点去检测变换的电信号。”

原始出处:

Nano Lett., 7 (6), 1717 -1722, 2007. 10.1021/nl0707104 S1530-6984(07)00710-2
Web Release Date: May 22, 2007 Copyright © 2007 American Chemical Society

p-n Semiconductor Membrane for Electrically Tunable Ion Current Rectification and Filtering

Maria E. Gracheva,* Julien Vidal, and Jean-Pierre Leburton*

Beckman Institute for Advanced Science and Technology, Department of Electrical and Computer Engineering University of Illinois at Urbana-Champaign, Urbana, Illinois 61801

Received March 26, 2007

Revised May 4, 2007

Abstract:

We show that a semiconductor membrane made of two thin layers of opposite (n- and p-) doping can perform electrically tunable ion current rectification and filtering in a nanopore. Our model is based on the solution of the 3D Poisson equation for the electrostatic potential in a double-cone nanopore combined with a transport model. It predicts that, for appropriate biasing of the membrane-electrolyte system, transitions from ohmic behavior to sharp rectification with vanishing leakage current are achievable. Furthermore, ion current rectifying and filtering regimes of the nanopore correspond to different charge states in the p-n membrane, which can be tuned with appropriate biasing of the n- and p- layers.