Quantitative Visualization of Nanoscale Ion Transport

Anal Chem. 2017 Dec 19;89(24):13603-13609. doi: 10.1021/acs.analchem.7b04139. Epub 2017 Dec 6.

Abstract

Understanding ion transport properties at various interfaces, especially at small length scales, is critical in advancing our knowledge of membrane materials and cell biology. Recently, we described potentiometric-scanning ion conductance microscopy (P-SICM) for ion-conductance measurement in polymer membranes and epithelial cell monolayers at discrete points in a sample. Here, we combine hopping mode techniques with P-SICM to allow simultaneous nanometer-scale conductance and topography mapping. First validated with standard synthetic membranes and then demonstrated in living epithelial cell monolayers under physiological conditions, this new method allows direct visualization of heterogeneous ion transport of biological samples for the first time. These advances provide a noncontact local probe, require no labeling, and present a new tool for quantifying intrinsic transport properties of a variety of biological samples.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Dielectric Spectroscopy
  • Dogs
  • Electric Conductivity
  • Ion Transport*
  • Madin Darby Canine Kidney Cells / chemistry*
  • Madin Darby Canine Kidney Cells / metabolism
  • Microscopy, Confocal
  • Nanopores
  • Polymers / chemistry*
  • Potentiometry

Substances

  • Polymers