Simultaneous mapping of nanoscale topography and surface potential of charged surfaces by scanning ion conductance microscopy
Simultaneous mapping of nanoscale topography and surface potential of charged surfaces by scanning ion conductance microscopy
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DOI：
10.1039/d0nr04555a
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发表时间：
2020-10-28
期刊：
影响因子：
6.7
通讯作者：
He, Jin
中科院分区：
文献类型：
--
作者：
Chen, Feng;Panday, Namuna;He, Jin
扫描离子电导显微镜（SICM）提供了获得活细胞膜的纳米级分辨率图像的能力。在这里，我们表明，双筒纳米移液管探针为基础的电位SICM（P-SICM）可以同时映射的地形和表面电位的软，粗糙和不均匀带电的表面在生理条件下。通过对模型样品的系统研究，对该技术进行了验证和测试，并基于有限元法（FEM）的模拟证实了其表面电位传感能力。使用P-SICM方法，我们比较了正常（Mela-A）和癌（B16）皮肤细胞膜的地形和细胞外电位分布。我们进一步监测了两种类型细胞的膜的结构和电变化后，将它们暴露于细胞外溶液中的钾离子浓度升高，已知去极化和损伤细胞。从表面电位成像，我们揭示了动态外观的异质性的表面电位的单个细胞膜。这种P-SICM方法为在纳米尺度上研究细胞膜的结构和电学性质提供了新的机会。
Scanning ion conductance microscopy (SICM) offers the ability to obtain nanoscale resolution images of the membranes of living cells. Here, we show that a dual-barrel nanopipette probe based potentiometric SICM (P-SICM) can simultaneously map the topography and surface potential of soft, rough and heterogeneously charged surfaces under physiological conditions. This technique was validated and tested by systematic studies on model samples, and the finite element method (FEM) based simulations confirmed its surface potential sensing capability. Using the P-SICM method, we compared both the topography and extracellular potential distributions of the membranes of normal (Mela-A) and cancerous (B16) skin cells. We further monitored the structural and electrical changes of the membranes of both types of cells after exposing them to the elevated potassium ion concentration in extracellular solution, known to depolarize and damage the cell. From surface potential imaging, we revealed the dynamic appearance of heterogeneity of the surface potential of the individual cell membrane. This P-SICM method provides new opportunities to study the structural and electrical properties of cell membrane at the nanoscale.