Fabrication and Characterization of Laser Pulled Platinum Microelectrodes with Controlled Geometry

Abstract

The development of a reproducible procedure for the fabrication of Pt disk-shaped microelectrodes with characteristic dimensions ranging from 50 nm to 1 μm in diameter was carried out using a laser pulling technique. The governing physical phenomena involved in their fabrication are discussed, and the importance of adding a critical quartz thinning step in the general procedure is demonstrated. The preparation of the microelectrodes involves sealing a platinum wire inside a quartz tubing using a pipet puller, thinning the composite material (platinum/quartz assembly), and laser pulling it to obtain two microelectrodes. The resulting microelectrodes display reproducible well-controlled geometry, which is important to downstream quantitative scanning electrochemical studies and imaging. Mechanical polishing of the microelectrode is required and remains the critical step in the fabrication of nanometer size electrodes. Following production, the microelectrodes are characterized by electron microscopy, scanning electrochemical microscopy, and cyclic voltammetry. Development of these microelectrodes is motivated by their subsequent application to electrocatalysis and their potential in theoretical study because of their well-defined geometry.

Local Evaluation of Processed Membrane Electrode Assemblies by Scanning Electrochemical Microscopy

“…20,21 Specifically, a quartz capillary (OD 0.9 mm, ID 0.3 mm, length 100 mm, Hilgenberg GmbH, Malsfeld) was cut to a length of 9 cm, rinsed once with 10% HNO 3 and several times with deionized water and dried at 100…”

Development of High-Resolution Scanning Electrochemical Microscopy for Nanoscale Topography and Electrochemical Simultaneous Imaging

“…Mezour and coworkers recently developed a reproducible procedure for the fabrication of Pt disk-shaped microelectrodes with diameters ranging from 50 nm to 1 µm using a laser pulling technique. 14 We developed a fabrication technique based on pyrolytic carbon deposition inside glass pipettes that enables the fabrication of nanoelectrodes with insulation of excellent integrity. 12,13 To fabricate the pyrolytic carbon electrode, a quartz glass capillary (O.D.…”

Scanning Electrochemical Microscopy as a Characterization Tool for Reduced Graphene Oxide Field Effect Transistors

“…The advantage of the constant distance mode is the decoupling of the electrochemical activity information from the topography [30,31]. Thus, changes in the recorded tip currents correspond only to changes in the electrochemical activity of the investigated surfaces and the current correlates to the tip position on the surface.…”

“…In order to demonstrate the imaging capability, the topography and the electrochemical activity of a blank SiO 2 /Si substrate, a GO substrate and a rGO substrate were measured. To verify the functionality and stability of the microelectrode, cyclic voltammetry (CV) measurements were done using standard protocols [30,31] before and after each surface investigation (results are presented in appendix A). A linear baseline was created for each surface investigation, starting with the current corresponding to the applied potential from before and ending with the current from after the measurement.…”