Electrochemical detection of HbA1c, a maker for diabetes, using a flow immunoassay system

Tsuyoshi Tanaka, Shoko Tsukube, Kojiro Izawa, Mina Okochi, Tae Kyu Lim, Shugo Watanabe, Manabu Harada, Tadashi Matsunaga*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

37 Citations (Scopus)


An on-chip electrochemical flow immunoassay system for the detection of hemoglobin A1c (HbA1c) was developed using anti-human hemoglobin (Hb) IgG labeled with ferrocene monocarboxylic acid (Fc-COOH) and boronate-affinity chromatography. An on-chip column packed with boronate-activated agarose beads was used for the separation of HbA1c from both non-glycated Hb and free antibody. Anti-human Hb IgG conjugated to Fc-COOH (Fc-IgG) was used for the electrochemical detection of HbA1c. The assay procedure included immunoreactions with Fc-IgG and HbA1c, separation of immunocomplexes by boronate affinity, and electrochemical detection of Fc-IgG-HbA1c immunocomplexes. The immunoreaction mixtures were injected onto a boronate-affinity column. HbA1c-antibody complexes were then trapped onto the column by the affinity of HbA1c to boronic acid. Subsequently, elution buffer containing sorbitol was applied to elute HbA1c-antibody complexes and a current was detected by applying 600 mV versus Ag/AgCl. The elution signal was an estimation of the HbA1c amount. A linear correlation between the increase of current and HbA1c concentration was obtained up to an HbA1c concentration of 500 μg/ml. The HbA1c flow immunoassay was successfully achieved using hemolysates. This electrochemical flow immunoassay system enabled us to construct a novel point-of-care testing device for the monitoring of glycated proteins including HbA1c.

Original languageEnglish
Pages (from-to)2051-2056
Number of pages6
JournalBiosensors and Bioelectronics
Issue number9-10
Publication statusPublished - 2007 Apr 15
Externally publishedYes


  • Boronate-affinity chromatography
  • Ferrocene monocarboxylic acid (Fc-COOH)
  • Hemoglobin A (HbA)
  • On-chip electrochemical flow immunoassay
  • Point-of-care testing device

ASJC Scopus subject areas

  • Biotechnology
  • Analytical Chemistry
  • Electrochemistry


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