title: On-chip type cation-exchange chromatography with ferrocene-labeled anti-hemoglobin antibody and electrochemical detector for determination of hemoglobin A1c level.
abstract: An on-chip type cation-exchange chromatography system with electrochemical detection of HbA(1c), which is one of the most important diabetes marker protein, was developed using ferrocene-conjugated anti-human hemoglobin (Hb) monoclonal antibody (FcAb). The FcAb was used as an electrochemical probe for the detection of each Hb. The system contains syringe pump, on-chip type cation-exchange column consisted of PDMS and cation-exchange resin beads, and a three-electrode flow-cell system. The separation conditions of HbA(1c) in blood calibrator samples from other Hbs, e.g. HbA(0), HbA(1a) or HbA(1b), were optimized using the on-chip type system. The electrochemical oxidation current from FcAb reacting with each Hb was measured at 350 mV (vs. Ag/AgCl). Hbs including HbA(1a) and HbA(1b), HbA(1c) and HbA(0) fractions were eluted in this order. A linear relationship between HbA(1c) levels and electrochemical oxidation currents was obtained in the range from 4.0% to 12.6% HbA(1c). All procedure including antigen-antibody reaction was completed in 15 min. Furthermore, a good correlation was obtained between KO500 method (HPLC) and our proposed method. These results indicate that the on-chip type system with electrochemical detection can be applied to a novel POCT device for rapid and precise detection of HbA(1c).
authors.affiliation: Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16 Naka-Cho, Koganei, Tokyo 184-8588, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Tanaka
authors.forename: Kojiro
authors.initials: K
authors.lastname: Izawa
authors.forename: Mina
authors.initials: M
authors.lastname: Okochi
authors.forename: Tae-Kyu
authors.initials: TK
authors.lastname: Lim
authors.forename: Shugo
authors.initials: S
authors.lastname: Watanabe
authors.forename: Manabu
authors.initials: M
authors.lastname: Harada
authors.forename: Tadashi
authors.initials: T
authors.lastname: Matsunaga