Microfluidic Separation of Redox Reactions for Coulometry Based on Metallization at the Mixed Potential

Kazuhiro Ikemoto, Takafumi Seki, Shohei Kimura, Yui Nakaoka, Shinnosuke Tsuchiya, Fumihiro Sassa, Masatoshi Yokokawa, Hiroaki Suzuki

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6 Citations (Scopus)

Abstract

Coulometric detection of an analyte in a solution at nanoliter scale was conducted by having redox reactions proceed simultaneously on a platinum electrode. The analyte was oxidized on a part of the electrode in one flow channel and silver was deposited on an array of circular microelectrodes formed in another flow channel at a mixed potential. Coulometric determination of the deposited silver showed a steep change in the generated charge as a result of the complete oxidation of silver. The short measurement time after the start of the coulometry suppressed the increase in background charge, resulting in significant lowering of the detection limit. The lower detection limit for H2O2 was 30 nM (3σ). To improve selectivity and minimize the influence of coexisting interferents, the shifting of the mixed potential, application of a permselective membrane, and electrochemical elimination of the interferents were effective modifications.

Original languageEnglish
Pages (from-to)9427-9434
Number of pages8
JournalAnalytical Chemistry
Volume88
Issue number19
DOIs
Publication statusPublished - Oct 4 2016
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Analytical Chemistry

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    Ikemoto, K., Seki, T., Kimura, S., Nakaoka, Y., Tsuchiya, S., Sassa, F., Yokokawa, M., & Suzuki, H. (2016). Microfluidic Separation of Redox Reactions for Coulometry Based on Metallization at the Mixed Potential. Analytical Chemistry, 88(19), 9427-9434. https://doi.org/10.1021/acs.analchem.6b01234