title: A simple biofuel cell cathode with human red blood cells as electrocatalysts for oxygen reduction reaction.
abstract: A red blood cell (RBC) from human exhibited direct electron transfer (DET) activity on a bare indium tin oxide (ITO) electrode. A formal potential of -0.152 V vs. a silver-silver chloride saturated potassium chloride (Ag|AgCl|KCl(satd.)) was estimated for the human RBC (type AB) from a pair of redox peaks at around 0.089 and -0.215 V (vs. Ag|AgCl|KCl(satd.)) on cyclic voltammetric (CV) measurements in a phosphate buffered saline (PBS; 39 mM; pH 7.4) solution. The results agreed well with those of a redox couple for iron-bearing heme groups in hemoglobin molecules (HbFe(II)/HbFe(III)) on the bare ITO electrodes, indicated that DET active species were hemoglobin (Hb) molecules encapsulated by a phospholipid bilayer membrane of the human RBC. The quantity of electrochemically active Hb in the human RBC was estimated to be 30 pmol cm(-2). In addition, the human RBC exhibited oxygen reduction reaction (ORR) activity in the dioxygen (O2) saturated PBS solution at the negative potential from ca. -0.15 V (vs. Ag|AgCl|KCl(satd.)). A single cell test proved that a biofuel cell (BFC) with an O2|RBC|ITO cathode showed the open-circuit voltage (OCV) of ca. 0.43 V and the maximum power density of ca. 0.68 μW cm(-2).
authors.affiliation: Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, 12-1 Ichigaya-Funagawara-machi, Shinjyuku-ku, Tokyo 162-0826, Japan. Electronic address: y-ayato@shinshu-u.ac.jp.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ayato
authors.affiliation: Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, 12-1 Ichigaya-Funagawara-machi, Shinjyuku-ku, Tokyo 162-0826, Japan.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Sakurai
authors.affiliation: Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, 12-1 Ichigaya-Funagawara-machi, Shinjyuku-ku, Tokyo 162-0826, Japan.
authors.forename: Saori
authors.initials: S
authors.lastname: Fukunaga
authors.affiliation: Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, 12-1 Ichigaya-Funagawara-machi, Shinjyuku-ku, Tokyo 162-0826, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Suganuma
authors.affiliation: Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, 12-1 Ichigaya-Funagawara-machi, Shinjyuku-ku, Tokyo 162-0826, Japan.
authors.forename: Kiyofumi
authors.initials: K
authors.lastname: Yamagiwa
authors.affiliation: Department of Chemical Science and Engineering, Tokyo National College of Technology, 1220-1 Kunugida-machi, Hachioji, Tokyo 193-0997, Japan.
authors.forename: Hidenobu
authors.initials: H
authors.lastname: Shiroishi
authors.affiliation: Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, 12-1 Ichigaya-Funagawara-machi, Shinjyuku-ku, Tokyo 162-0826, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Kuwano
mesh_terms: D001674:Bioelectric Energy Sources; D002384:Catalysis; D002478:Cells, Cultured; D011211:Electric Power Supplies; D004563:Electrochemistry / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D004912:Erythrocytes / Q000502:physiology*; D006801:Humans; D010084:Oxidation-Reduction
keywords: Biofuel cell; Direct electron transfer; Hemoglobin; Indium-tin-oxide (ITO) electrode; Oxygen reduction reaction; Red blood cell