Measurement of Ion Currents through Porous Membranes with Scanning Ion Conductance Microscopy
Measurement of Ion Currents through Porous Membranes with Scanning Ion Conductance Microscopy
复制标题
DOI：
10.1021/ac900065p
复制
发表时间：
2009-06-15
影响因子：
7.4
通讯作者：
Baker, Lane A.
中科院分区：
文献类型：
--
作者：
Chen, Chiao-Chen;Derylo, Maksymilian A.;Baker, Lane A.
扫描离子电导显微镜（SICM）被用来询问从聚合物膜的纳米级孔发出的离子电流。通过检查同时记录的离子电流图像和相应的地形图像来测量单个孔的运输活性。通过在扩散池的上腔室和下腔室之间引入浓度差来产生单个纳米孔上的局部离子电流。为了更好地估计这些局部化的离子电流，Goldman-Hodgkin-Katz（GHK）理论被用于在浓度和施加的电势的梯度下模拟通过渗透膜的离子电流。实验离子电流分布在一个单一的孔拟合与理论图计算GHK模型。在此分析的基础上，可以用SICM测量纳米尺度的输运性质。
Scanning ion conductance microscopy (SICM) was used to interrogate ion currents emanating from nanometer-scale pores of a polymer membrane. The transport activity of individual pores was measured by examining ion current images and corresponding topographic images recorded simultaneously. Localized ion currents over individual nanopores were generated by introducing a concentration difference between the upper and lower chambers of a diffusion cell. To better estimate these localized ion currents, Goldman-Hodgkin-Katz (GHK) theory was used to model ion current through a permeable membrane under gradients of both concentration and applied potential. Experimental ion current profiles over a single pore fit well with theoretical plots calculated from the GHK model. On the basis of this analysis, nanoscale transport properties can be measured with SICM.