Interdigitated array microelectrodes as electrochemical sensors

Masao Morita, Osamu Niwa, Tsutomu Horiuchi

Research output: Contribution to journalArticle

99 Citations (Scopus)

Abstract

We investigated electrochemical measurements with interdigitated array (IDA) electrodes in both stationary solutions and flow systems. In a stationary solution, we achieved a very low detection limit of 10 pM of reversible redox species by using substitutional stripping voltammetry, which is a new type of stripping voltammetry using an IDA microelectrode. In flow systems, current enhancement by redox cycling is less effective than that in a stationary solution. The flow rate dependence of redox cycling is constant in the amperometric region, varies with coulometric yield in the quasi-amperometric region, and is inversely proportional to the 2/3 power of the volume flow rate in the coulometric region. A low detection limit of 5 fg (32 amol) is obtained for dopamine due to the high current density and low background noise level (0.1 pA) at the carbon-based IDA microelectrode used as a detector for liquid chromatography. A new separation approach is demonstrated which combines electrochemical detection and a molecular template. The electrode is first partly covered with print molecules and then modified with silane coupling reagent. The catechol-imprinted electrode shows the usual diffusion-limited cyclic voltammogram of catechol and has a diminished response against all catecholamines. The selectivity between catechol and epinephrine is about 100 when the electrode is used as an electrochemical detector in liquid chromatography.

Original languageEnglish
Pages (from-to)3177-3183
Number of pages7
JournalElectrochimica Acta
Volume42
Issue number20-22
DOIs
Publication statusPublished - 1997 Jan 1
Externally publishedYes

Keywords

  • Molecular template
  • Quasi-amperometric detection
  • Selective detection
  • Substitutional stripping voltammetry

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Electrochemistry

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