title: Simultaneous visualization of surface topography and concentration field by means of scanning electrochemical microscopy using a single electrochemical probe and impedance spectroscopy.
abstract: Scanning electrochemical microscopy visualizes concentration profiles. To determine the location of the probe relative to topographical features of the substrate, knowledge of the probe-to-sample distance at each probe position is required. The use of electrochemical impedance spectroscopy for obtaining information on the substrate-to-probe distance and on the concentration of interest using the electrochemical probe alone is suggested. By tuning the frequencies of interrogation, the probe-to-substrate distance can be derived followed by interrogation of processes that carry information on concentration at lower frequencies. These processes may include charge-transfer relaxation, diffusional relaxation at the electrode, and open-circuit potential at zero frequency. A potentiometric chloride sensing microprobe is used herein to reconstruct both topography and the concentration field at a microscopic diffusional source of chloride.
authors: Analytische Chemie-Elektroanalytik & Sensorik, Ruhr-Universität Bochum, 44780 Bochum, Germany.
authors: Maike
authors: M
authors: Pähler
authors: Wolfgang
authors: W
authors: Schuhmann
authors: Miklós
authors: M
authors: Gratzl
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002712:Chlorides / Q000032:analysis; D017097:Electric Impedance; D004563:Electrochemistry; D017736:Ion-Selective Electrodes; D008839:Microelectrodes; D020527:Microscopy, Scanning Probe / Q000295:instrumentation / Q000379:methods*; D008956:Models, Chemical; D011199:Potentiometry; D012996:Solutions; D013499:Surface Properties
chemical_list: D002712:Chlorides; D012996:Solutions