title: Synthesis of palladium/helical carbon nanofiber hybrid nanostructures and their application for hydrogen peroxide and glucose detection.
abstract: We report on a novel sensing platform for H2O2 and glucose based on immobilization of palladium-helical carbon nanofiber (Pd-HCNF) hybrid nanostructures and glucose oxidase (GOx) with Nafion on a glassy carbon electrode (GCE). HCNFs were synthesized by a chemical vapor deposition process on a C60-supported Pd catalyst. Pd-HCNF nanocomposites were prepared by a one-step reduction free method in dimethylformamide (DMF). The prepared materials were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Raman spectroscopy. The Nafion/Pd-HCNF/GCE sensor exhibits excellent electrocatalytic sensitivity toward H2O2 (315 mA M(-1) cm(-2)) as probed by cyclic voltammetry (CV) and chronoamperometry. We show that Pd-HCNF-modified electrodes significantly reduce the overpotential and enhance the electron transfer rate. A linear range from 5.0 μM to 2.1 mM with a detection limit of 3.0 μM (based on the S/N = 3) and good reproducibility were obtained. Furthermore, a sensing platform for glucose was prepared by immobilizing the Pd-HCNFs and glucose oxidase (GOx) with Nafion on a glassy carbon electrode. The resulting biosensor exhibits a good response to glucose with a wide linear range (0.06-6.0 mM) with a detection limit of 0.03 mM and a sensitivity of 13 mA M(-1) cm(-2). We show that small size and homogeneous distribution of the Pd nanoparticles in combination with good conductivity and large surface area of the HCNFs lead to a H2O2 and glucose sensing platform that performs in the top range of the herein reported sensor platforms.
authors.affiliation: Department of Physics, Umeå University , S-901 87 Umeå, Sweden.
authors.forename: Xueen
authors.initials: X
authors.lastname: Jia
authors.forename: Guangzhi
authors.initials: G
authors.lastname: Hu
authors.forename: Florian
authors.initials: F
authors.lastname: Nitze
authors.forename: Hamid Reza
authors.initials: HR
authors.lastname: Barzegar
authors.forename: Tiva
authors.initials: T
authors.lastname: Sharifi
authors.forename: Cheuk-Wai
authors.initials: CW
authors.lastname: Tai
authors.forename: Thomas
authors.initials: T
authors.lastname: Wågberg
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology; D002244:Carbon / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods*; D004800:Enzymes, Immobilized / Q000737:chemistry; D005656:Fungal Proteins / Q000737:chemistry; D005947:Glucose / Q000032:analysis*; D005949:Glucose Oxidase / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000032:analysis*; D057139:Nanofibers / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D012680:Sensitivity and Specificity
chemical_list: D004800:Enzymes, Immobilized; D005656:Fungal Proteins; D010165:Palladium; D002244:Carbon; D006861:Hydrogen Peroxide; D005949:Glucose Oxidase; D005947:Glucose