Polarization Effect of a Dielectric Membrane on the Ionic Current Rectification in a Conical Nanopore

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• 作者：Bingkai Zhang ; Ye Ai ; Jing Liu ; Sang W. Joo ; Shizhi Qian
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：December 22, 2011
• 年：2011
• 卷：115
• 期：50
• 页码：24951-24959
• 全文大小：1068K
• 年卷期：v.115,no.50(December 22, 2011)
• ISSN：1932-7455

文摘

Ionic current rectification (ICR) refers to a phenomenon that an ionic current flowing through a nanopore exhibits a preferential direction. In this paper, we investigate the ICR phenomenon in a conical nanopore embedded within a dielectric membrane using a continuum-based model, which is composed of the Nernst鈥揚lanck (NP) equations for the ionic mass transport, the Poisson equation for the electrostatics, and the Navier鈥揝tokes (NS) equations for the flow field. Different from the existing studies, the emphasis of this investigation is placed on the polarization effect of the dielectric membrane on the ionic current and ICR in a conical nanopore. The results show that the polarization effect can influence the ion current and ICR, especially under the conditions of a relatively low 魏R_t, which is the ratio of the nanopore tip radius and the Debye length, and a relatively low surface charge density of the nanopore.