A high-resolution probe for localized electrochemical impedance spectroscopy measurements

A high-resolution probe consisting of two platinum microelectrodes, 10 mu m in diameter, that permits localized electrochemical impedance spectroscopy measurements was developed and tested. The measurements were made using platinum disks as current sources with defined geometry in an insulating plane. The ac current distribution measured in solution using the probe was compared with analytical solutions and computer simulations. The spatial resolution of the probe was tested and defined by varying the height of the probe and the distance between the microelectrodes.