title: Amperometric hydrogen peroxide and glucose biosensor based on NiFe2/ordered mesoporous carbon nanocomposites.
abstract: Nanocomposites of NiFex embedded in ordered mesoporous carbon (OMC) (x = 0, 1, 2) were prepared by a wet impregnation and hydrogen reduction process and were used to construct electrochemical biosensors for the amperometric detection of hydrogen peroxide (H2O2) or glucose. The NiFe2/OMC nanocomposites were demonstrated to have a large surface area, suitable mesoporous channels, many edge-plane-like defective sites, and a good distribution of alloyed nanoparticles. The NiFe2/OMC and Nafion modified glass carbon electrode (GCE) exhibited excellent electrocatalytic activities toward the reduction of H2O2 as well. By utilizing it as a bioplatform, GOx (glucose oxidase) cross-linked with Nafion was immobilized on the surface of the electrode for the construction of an amperometric glucose biosensor. Our results indicated that the amperometric hydrogen peroxide biosensor (NiFe2/OMC + Nafion + GCE) showed good analytical performances in term of a high sensitivity of 4.29 μA mM(-1) cm(-2), wide linearity from 6.2 to 42,710 μM and a low detection limit of 0.24 μM at a signal-to-noise ratio of 3 (S/N = 3). This biosensor exhibited excellent selectivity, high stability and negligible interference for the detection of H2O2. In addition, the immobilized enzyme on NiFe2/OMC + Nafion + GCE, retaining its bioactivity, exhibited a reversible two-proton and two-electron transfer reaction, a fast heterogeneous electron transfer rate and an effective Michaelis-Menten constant (K) (3.18 mM). The GOx + NiFe2/OMC + Nafion + GCE could be used to detect glucose based on the oxidation of glucose catalyzed by GOx and exhibited a wide detection range of 48.6-12,500 μM with a high sensitivity of 6.9 μA mM(-1) cm(-2) and a low detection limit of 2.7 μM (S/N = 3). The enzymic biosensor maintained a high selectivity and stability features, and shows great promise for application in the detection of glucose.
authors.affiliation: School of Material Science and Engineering, Shandong Jianzhu University, Jinan 250101, P. R. China. xiang@sdjzu.edu.cn.
authors.forename: Dong
authors.initials: D
authors.lastname: Xiang
authors.forename: Longwei
authors.initials: L
authors.lastname: Yin
authors.forename: Jingyun
authors.initials: J
authors.lastname: Ma
authors.forename: Enyan
authors.initials: E
authors.lastname: Guo
authors.forename: Qun
authors.initials: Q
authors.lastname: Li
authors.forename: Zhaoqiang
authors.initials: Z
authors.lastname: Li
authors.forename: Kegao
authors.initials: K
authors.lastname: Liu
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods; D004800:Enzymes, Immobilized / Q000378:metabolism; D005947:Glucose / Q000032:analysis*; D005949:Glucose Oxidase / Q000737:chemistry / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000032:analysis*; D007501:Iron / Q000737:chemistry; D053761:Nanocomposites / Q000737:chemistry*; D037742:Nanotubes, Carbon; D009532:Nickel / Q000737:chemistry; D010084:Oxidation-Reduction
chemical_list: D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D009532:Nickel; D006861:Hydrogen Peroxide; D007501:Iron; D005949:Glucose Oxidase; D005947:Glucose