title: Electrochemistry and electrocatalysis of myoglobin immobilized in sulfonated graphene oxide and Nafion films.
abstract: In this study, sulfonated graphene oxide (SGO) was synthesized and characterized by Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS). It was used to make Mb-SGO-Nafion composite films by coating myoglobin (Mb) on the glassy carbon electrodes (GCE). Positions of the Soret absorption bands suggested that Mb retained its native conformation in the films. Mb-SGO-Nafion film modified electrode showed a pair of well-defined and nearly reversible cyclic voltammetry peaks at around -0.39 V versus saturated calomel electrode (SCE) in pH 7.0 buffers, characteristic of heme Fe(III)/Fe(II) redox couples. Electrochemical parameters such as electron transfer rate constant (ks) and formal potential (E(o')) were estimated by fitting the data of square-wave voltammetry with nonlinear regression analysis. Experimental data demonstrated that the electron transfer between Mb and electrode was greatly facilitated and showed good electrocatalytic properties toward various substrates, such as H2O2 and NaNO2, with significant lowering of reduction overpotential.
authors.affiliation: Institute of Multifunctional Materials (IMM), Laboratory of New Fiber Materials and Modern Textile, College of Chemistry, Chemical Engineering, and Environment, Qingdao University, Qingdao, 266071, China.
authors.forename: Guiying
authors.initials: G
authors.lastname: Chen
authors.affiliation: Institute of Multifunctional Materials (IMM), Laboratory of New Fiber Materials and Modern Textile, College of Chemistry, Chemical Engineering, and Environment, Qingdao University, Qingdao, 266071, China. Electronic address: sun_hong@qdu.edu.cn.
authors.forename: Hong
authors.initials: H
authors.lastname: Sun
authors.affiliation: School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China.
authors.forename: Shifeng
authors.initials: S
authors.lastname: Hou
mesh_terms: D000818:Animals; D002384:Catalysis; D055664:Electrochemical Techniques; D005465:Fluorocarbon Polymers / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D006736:Horses; D055767:Immobilized Proteins / Q000737:chemistry*; D009211:Myoglobin / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D017550:Spectroscopy, Fourier Transform Infrared; D013451:Sulfonic Acids / Q000737:chemistry*
chemical_list: D005465:Fluorocarbon Polymers; D055767:Immobilized Proteins; D009211:Myoglobin; D010087:Oxides; D013451:Sulfonic Acids; C040402:perfluorosulfonic acid; D006108:Graphite
keywords: Electrocatalysis; Electrochemistry; Myoglobin; Sulfonated graphene oxide