KENBIKYO Vol.48▶No.3 2013
â– Feature Articles: Novel Microscopic Characterization Techniques Using Nanoscale Ion Probes

Application of Scanning Ion Conductance Microscopy to Biosciences

Masato Nakajima and Tatsuo Ushiki

Abstract: The scanning ion conductance microscope (SICM), introduced by Hansma et al., in 1989, uses an electrolyte-filled micropipette electrode as a sensitive probe and detects the ion current between the probe and the bath electrode in an electrolyte solution. When the probing tip approaches the sample surface in the solution, the ion current decreases because the space through which ions can flow is decreased. By monitoring the change in ion current, SICM can obtain contact-free images of the sample topography. This technique is expected to be useful for studying the surface structure of soft biological samples under liquid conditions. In this paper, we explained the principle of the SICM and showed some results of the application of SICM to biosciences. We showed SICM images of collagen fibrils and cultivated cells in liquid. Sequential time-lapsed SICM images of live cells were also shown for investigating the movement of cellular processes on the time scale of minutes. We then applied SICM to the study on the surface topography of tissue blocks (e.g., trachea, etc.). The advantages of SICM imaging in biosciences were discussed by comparison with imaging by scanning electron microscopy.

Key words: scanning ion conductance microscope, scanning probe microscope, hopping mode, collagen fibrils, cultivated cells