Pipette-Surface Interaction: Current Enhancement and Intrinsic Force
Pipette-Surface Interaction: Current Enhancement and Intrinsic Force
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DOI：
10.1021/ja3094586
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发表时间：
2013-01-09
影响因子：
15
通讯作者：
Klenerman, David
中科院分区：
文献类型：
--
作者：
Clarke, Richard W.;Zhukov, Alexander;Klenerman, David
玻璃和细胞表面之间存在固有的排斥力，其允许对细胞进行非侵入性扫描离子电导显微镜（SICM），并且必须克服该排斥力以形成用于离子通道的膜片钳研究的Gigaseals。然而，在电解质的生理溶液中的表面的相互作用，包括这种排斥的存在，例如，不明显同意标准的Derjaguin-Landau-Verwey-Overbeek（DLVO）胶体理论准确在低得多的盐浓度。在本文中，我们研究了玻璃纳米移液管在这种高盐制度与各种表面的相互作用，并提出了一种方法来解决DLVO理论的结果。我们证明了这种理解的实用性SICM地形图绘制活细胞的细胞骨架。我们还报告了一个有趣的效果，即通过纳米移液管的离子电流可以在某些条件下接近绝缘表面时增加，而不是像预期的那样减少。我们建议，这是由于电渗流分离，高盐电动效应。总的来说，这些实验产生的基本相互作用，发生在强电解质溶液中的表面之间的关键见解。
There is an intrinsic repulsion between glass and cell surfaces that allows noninvasive scanning ion conductance microscopy (SICM) of cells and which must be overcome in order to form the gigaseals used for patch clamping investigations of ion channels. However, the interactions of surfaces in physiological solutions of electrolytes, including the presence of this repulsion, for example, do not obviously agree with the standard Derjaguin-Landau-Verwey-Overbeek (DLVO) colloid theory accurate at much lower salt concentrations. In this paper we investigate the interactions of glass nanopipettes in this high-salt regime with a variety of surfaces and propose a way to resolve DLVO theory with the results. We demonstrate the utility of this understanding to SICM by topographically mapping a live cell's cytoskeleton. We also report an interesting effect whereby the ion current though a nanopipette can increase under certain conditions upon approaching an insulating surface, rather than decreasing as would be expected. We propose that this is due to electroosmotic flow separation, a high-salt electrokinetic effect. Overall these experiments yield key insights into the fundamental interactions that take place between surfaces in strong solutions of electrolytes.