Preparation and Electrochemical Characterization of Conical and Hemispherical Ultramicroelectrodes

Reginald M. Penner, Michael J. Heben, Nathan S. Lewis

Research output: Contribution to journalArticlepeer-review

90 Citations (Scopus)


We describe a new ultramicroelectrode fabrication technique that has allowed the preparation of conical Pt-Ir ultramicroelectrodes with radii of 0.5-10 μm. These electrodes have been characterized by scanning electron microscopy, cyclic voltammetry, and chronoamperometry. The smallest radii electrodes (r < 2 μm) exhibited diffusional behavior at times longer than 70 μs in accord with a hemispherical geometry, while larger radii electrodes exhibited diffusional behavior consistent with a conical geometry. A first-order mathematical approach to diffusion at conical surfaces has been developed to explain these results.

Original languageEnglish
Pages (from-to)1630-1636
Number of pages7
JournalAnalytical Chemistry
Issue number15
Publication statusPublished - Aug 1989

ASJC Scopus subject areas

  • Analytical Chemistry

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