生物谷報道：伊利諾斯州立大學(xué)研究人員設(shè)計(jì)的一種半導(dǎo)體膜能夠具有比生物膜更靈活、更好的電性能,。采用摻有雜質(zhì)的硅層，這種固態(tài)膜還可用于單分子檢測,、蛋白過濾和DNA測序,。研究結(jié)果刊登于Nano Letters雜志。
文章高級作者Jean-Pierre Leburton 說：“通過在這層膜上制作納米孔,，我們可以用此膜分離帶電荷的物種或者調(diào)控帶電荷的分子流和離子流,，從而模仿生物離子通道的運(yùn)轉(zhuǎn)。”Leburton率領(lǐng)的研究小組在許多靜電勢下模擬此半導(dǎo)體膜的運(yùn)轉(zhuǎn),。
研究模型中,，納米孔-膜結(jié)構(gòu)是由兩層硅組成，每層厚12納米,，攜帶對立的（n和p）半導(dǎo)體雜質(zhì),。膜的n面是正極，p面是負(fù)極,。納米孔是沙漏狀,，頸部直徑為1納米，在每面開口的直徑為6納米,?？梢酝ㄟ^改變電勢而改變納米孔的型號。
通過控制離子流,，人造納米孔提供了生物離子通道所不具備的一定程度的可調(diào)性（tunability）,。除了可作為生物離子通道的替代品,，這種固態(tài)納米孔和膜還有其它用途，比如DNA測序,。
研究人員說：“利用半導(dǎo)體膜技術(shù)測序DNA分子,，既省時又省錢，通過偏置跨膜電壓,，我們能夠從納米孔拔出DNA,。因?yàn)槊繉A基都攜帶的電荷不同，我們可以將這種膜作為p-n 結(jié)合點(diǎn)去檢測變換的電信號,。”
原始出處:
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.
