title: Simultaneous noncontact topography and electrochemical imaging by SECM/SICM featuring ion current feedback regulation.
abstract: We described a hybrid system of scanning electrochemical microscopy (SECM) and scanning ion conductance microscopy (SICM) with ion current feedback nanopositioning control for simultaneous imaging of noncontact topography and spatial distribution of electrochemical species. A nanopipette/nanoring electrode probe provided submicrometer resolution of the electrochemical measurement on surfaces with complex topology. The SECM/SICM probe had an aperture radius of 220 nm. The inner and outer radii of the SECM Au nanoring electrode were 330 and 550 nm, respectively. Characterization of the probe was performed with scanning electron microscopy (SEM), cyclic voltammetry (CV), and approach curve measurements. SECM/SICM was applied to simultaneous imaging of topography and electrochemical responses of enzymes (horse radish peroxidase (HRP) and glucose oxidase (GOD)) and single live cells (A6 cells, superior cervical ganglion (SCG) cells, and cardiac myocytes). The measurements revealed the distribution of activity of the enzyme spots on uneven surfaces with submicrometer resolution. SECM/SICM acquired high resolution topographic images of cells together with the map of electrochemical signals. This combined technique was also applied to the evaluation of the permeation property of electroactive species through cellular membranes.
authors.affiliation: Graduate School of Environmental Studies, Tohoku University, Aramaki Aoba 6-6-11-605, Sendai 980-8579, Japan.
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Andrew I
authors.initials: AI
authors.lastname: Shevchuk
authors.forename: Pavel
authors.initials: P
authors.lastname: Novak
authors.forename: Yumi
authors.initials: Y
authors.lastname: Murakami
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Shiku
authors.forename: Yuri E
authors.initials: YE
authors.lastname: Korchev
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Matsue
mesh_terms: D000818:Animals; D002417:Cattle; D002460:Cell Line; D002463:Cell Membrane Permeability; D002470:Cell Survival; D004563:Electrochemistry; D004566:Electrodes; D005949:Glucose Oxidase / Q000378:metabolism; D006735:Horseradish Peroxidase / Q000378:metabolism; D008853:Microscopy / Q000295:instrumentation / Q000379:methods*; D057054:Molecular Imaging; D040081:Protein Array Analysis
chemical_list: D005949:Glucose Oxidase; D006735:Horseradish Peroxidase