Topographical and electrochemical nanoscale imaging of living cells using voltage-switching mode scanning electrochemical microscopy

Yasufumi Takahashi, Andrew I. Shevchuk, Pavel Novak, Babak Babakinejad, Julie Macpherson, Patrick R. Unwin, Hitoshi Shiku, Julia Gorelik, David Klenerman, Yuri E. Korchev, Tomokazu Matsue

Research output: Contribution to journalArticle

141 Citations (Scopus)

Abstract

We describe voltage-switching mode scanning electrochemical microscopy (VSM-SECM), in which a single SECM tip electrode was used to acquire high-quality topographical and electrochemical images of living cells simultaneously. This was achieved by switching the applied voltage so as to change the faradaic current from a hindered diffusion feedback signal (for distance control and topographical imaging) to the electrochemical flux measurement of interest. This imaging method is robust, and a single nanoscale SECM electrode, which is simple to produce, is used for both topography and activity measurements. In order to minimize the delay at voltage switching, we used pyrolytic carbon nanoelectrodes with 6.5-100 nm radii that rapidly reached a steady-state current, typically in less than 20 ms for the largest electrodes and faster for smaller electrodes. In addition, these carbon nanoelectrodes are suitable for convoluted cell topography imaging because the RG value (ratio of overall probe diameter to active electrode diameter) is typically in the range of 1.5-3.0. We first evaluated the resolution of constant-current mode topography imaging using carbon nanoelectrodes. Next, we performed VSM-SECM measurements to visualize membrane proteins on A431 cells and to detect neurotransmitters from a PC12 cells. We also combined VSM-SECM with surface confocal microscopy to allow simultaneous fluorescence and topographical imaging. VSM-SECM opens up new opportunities in nanoscale chemical mapping at interfaces, and should find wide application in the physical and biological sciences.

Original languageEnglish
Pages (from-to)11540-11545
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume109
Issue number29
DOIs
Publication statusPublished - 2012 Jul 17

Keywords

  • Constant-distance mode
  • High-resolution imaging
  • Living cell imaging
  • Noninvasive

ASJC Scopus subject areas

  • General

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