Alternating current impedance imaging of membrane pores using scanning electrochemical microscopy
Alternating current impedance imaging of membrane pores using scanning electrochemical microscopy
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DOI：
10.1021/ac050453s
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发表时间：
2005-09-01
影响因子：
7.4
通讯作者：
Baker, LA
中科院分区：
文献类型：
--
作者：
Ervin, EN;White, HS;Baker, LA
描述了使用扫描电化学显微镜（SECM）对含有圆锥形孔（60 nm和2.5 μ m直径开口）的6 μ m厚膜进行交流阻抗成像。孔开口的阻抗图像，通过光栅的玻璃密封的圆锥形的Pt尖端（类似于1 μ m半径）以上的膜表面，同时测量之间的总阻抗的尖端和位于膜的相对侧的大面积Pt电极。在SECM阻抗图像中观察到高孔密度膜中的单个孔开口（类似于8 × 10（4）孔/cm（2））。图像对比度是由于在孔开口附近的尖端和膜电阻的降低。提出了SECM细胞和膜的等效电路，并对测得的SECM成像阻抗进行了评价。标准采用SECM在阻抗模式图像膜进行了讨论。
Alternating current impedance imaging of a 6-mu m thick membrane containing conical-shaped pores (60-nm and 2.5-mu m diameter openings) using scanning electrochemical microscopy (SECM) is described. Impedance images of the pore openings were obtained by rastering a glass-sealed conically shaped Pt tip (similar to 1-mu m radius) above the membrane surface, while measuring the total impedance between the tip and a large area Pt electrode located on the opposite side of the membrane. Individual pore openings in the high pore density membrane (similar to 8 x 10(4) pores/cm(2)) are observed in the SECM impedance image. The image contrast is due to the decrease in tip and membrane resistance, in the vicinity of the pore opening. An equivalent circuit for the SECM cell and membrane is proposed and evaluated against the measured SECM imaging impedance. Criteria for employing SECM in impedance mode to image membranes are discussed.