title: Direct electrochemistry and electrocatalysis of glucose oxidase immobilized on reduced graphene oxide and silver nanoparticles nanocomposite modified electrode.
abstract: The direct electrochemistry of glucose oxidase (GOx) was successfully realized on electrochemically reduced graphene oxide and silver nanoparticles (RGO/Ag) nanocomposite modified electrode. The fabricated nanocomposite was characterized by field emission scanning electron microscope and energy dispersive spectroscopy. The GOx immobilized nanocomposite modified electrode showed a pair of well-defined redox peaks with a formal potential (E°) of -0.422 V, indicating that the bioactivity of GOx was retained. The heterogeneous electron transfer rate constant (Ks) of GOx at the nanocomposite was calculated to be 5.27 s(-1), revealing a fast direct electron transfer of GOx. The GOx immobilized RGO/Ag nanocomposite electrode exhibited a good electrocatalytic activity toward glucose over a linear concentration range from 0.5 to 12.5 mM with a detection limit of 0.16 mM. Besides, the fabricated biosensor showed an acceptable sensitivity and selectivity for glucose.
authors.affiliation: Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan, ROC.
authors.forename: Selvakumar
authors.initials: S
authors.lastname: Palanisamy
authors.affiliation: Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan, ROC.
authors.forename: Chelladurai
authors.initials: C
authors.lastname: Karuppiah
authors.affiliation: Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan, ROC. Electronic address: smchen78@ms15.hinet.net.
authors.forename: Shen-Ming
authors.initials: SM
authors.lastname: Chen
mesh_terms: D015374:Biosensing Techniques; D002384:Catalysis; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D005949:Glucose Oxidase / Q000378:metabolism*; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*
chemical_list: D004800:Enzymes, Immobilized; D010087:Oxides; D012834:Silver; D006108:Graphite; D005949:Glucose Oxidase; D005947:Glucose
keywords: Direct electron transfer; Glucose biosensor; Glucose oxidase; Reduced graphene oxide; Silver nanoparticles