Title:
Simultaneous Noncontact Topography and Electrochemical Nanoscale Imaging by using Scanning Probe Microscope
Yasufumi Takahashi
World Premier International Research Center-Advanced Institute for Materials Research, Tohoku University, Katahira, Aoba 2-1-1, Sendai 980-8577, Japan
takahashi@bioinfo.che.tohoku.ac.jp
Abstract:
The dynamics of chemical and biological processes at interfaces underpin a wide range of phenomena, from surface adsorption and crystal growth to signal transduction at the cell membrane. Since many interfaces have nanoscale structures which control these phenomena, it is vital to be able to perform measurements of chemical and biochemical fluxes on this length scale. One technique with the potential to measure chemically specific fluxes on the nanoscale is scanning electrochemical microscopy (SECM). SECM uses a micro- or nanoelectrode as a scanning probe and provides sample surface electrochemical property under physiological conditions without physical contact. SECM has been applied for evaluating the enzyme and cellular activity, estimating cell membrane permeability, and detecting electroactive metabolic chemicals with short life spans, such as neurotransmitters and nitric oxide in the vicinity of living cellular surfaces.
A fine distance regulation system is required to approach the electrode against live cell surfaces. Scanning ion conductance microscopy (SICM) uses a nanopipette as a scanning probe and provides living cell surface topography images under physiological conditions without physical contact. SICM is based on the phenomenon that the ion flow through a sharp fluid-filled nanopipette is partially occluded when the nanopipette approaches the surface of a sample. Living cell surface topography and dynamic measurements have been performed.
In this lecture, I would like to talk about a hybrid system of SECM and SICM for simultaneous nanoscale imaging of topography and electrochemical signal. This system is particularly suitable for detailed characterization of soft biomaterials with complex 3D structures, such as live cells.
