title: Direct electrochemistry and bioelectrocatalysis of hemoglobin immobilized on carbon black.
abstract: It is reported for the first time that hemoglobin (Hb) was immobilized on the surface of carbon black powders modified at the surface of a glassy carbon electrode. The cyclic voltammetric results showed that the immobilized Hb could undergo a direct quasi-reversible electrochemical reaction. Its formal potential, E(0), is -0.330 V in phosphate buffer solution (pH 6.9) at a scan rate of 100 mV/s and is almost independent of the scan rate in the range of 40-200 mV/s. The dependence of E(0), on the pH of the buffer solution indicated that the conversion of Hb-Fe(III)/Hb-Fe(II) is a one-electron-transfer reaction process coupled with one-proton-transfer. The experimental results also demonstrated that the immobilized Hb retained its bioelectrocatalytic activity for the reduction of H(2)O(2). Furthermore, the immobilized Hb can be stored at 4 degrees C for several weeks without any loss of the enzyme activity. Thus, the immobilized Hb may be used as a biocathodic catalyst in biofuel cells.
authors.affiliation: Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, PR China.
authors.forename: Guo-Xian
authors.initials: GX
authors.lastname: Ma
authors.forename: Tian-Hong
authors.initials: TH
authors.lastname: Lu
authors.forename: Yong-Yao
authors.initials: YY
authors.lastname: Xia
mesh_terms: D000818:Animals; D002384:Catalysis; D002417:Cattle; D004563:Electrochemistry; D004566:Electrodes; D005290:Ferric Compounds / Q000378:metabolism; D005296:Ferrous Compounds / Q000378:metabolism; D006418:Heme / Q000378:metabolism; D006454:Hemoglobins / Q000737:chemistry* / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D010084:Oxidation-Reduction; D011489:Protein Denaturation; D053260:Soot / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D005290:Ferric Compounds; D005296:Ferrous Compounds; D006454:Hemoglobins; D053260:Soot; D006418:Heme; D006861:Hydrogen Peroxide