Characterization of electrode fouling and surface regeneration for a platinum electrode on an electrophoresis microchip

Drew P. Manica, Yutaro Mitsumori, Andrew G. Ewing

Research output: Contribution to journalArticlepeer-review

103 Scopus citations

Abstract

A method of electrochemically cleaning noble metal electrodes is presented and characterized for electrophoresis microchips with electrochemical detection. First, the loss of sensitivity due to electrode fouling by serotonin is characterized as a function of injection number and analyte concentration. Signal attenuation is observed to be greater at high concentrations (100 μM) and negligible at very low concentrations (∼1 μM). Next, an electrochemical treatment procedure is optimized to yield sensitive and reproducible amperometric detection of the highly adsorptive compounds, serotonin and histamine. Thus, the performance of the electrode is reproducibly regenerated following as much as a ∼99% reduction in surface activity. Utilizing the optimized three-level waveform, derived from that used for pulsed amperometric detection, detection limits as low as 78 nM and 17 μM have been obtained for serotonin and histamine, respectively. In the case of serotonin, this represents the lowest detection limit for a neurotransmitter by microchip electrophoresis with amperometric detection and the first report of amperometric detection of histamine detection at an unmodified platinum electrode. Repeated use of the electrode and application of electrochemical treatment did not appear to measurably affect the noise, longevity, metal adhesion, or physical appearance of the electrode.

Original languageEnglish (US)
Pages (from-to)4572-4577
Number of pages6
JournalAnalytical Chemistry
Volume75
Issue number17
DOIs
StatePublished - Sep 1 2003

All Science Journal Classification (ASJC) codes

  • Analytical Chemistry

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