title: Direct electron transfer of glucose oxidase immobilized on a mesoporous silica KIT-6 matrix to screen-printed electrodes.
abstract: The direct electron transfer of glucose oxidase (GOx) immobilized on a large-pore mesoporous silica KIT-6 matrix fixed to a screen-printed electrode (SPE) and its application as a disposable biosensor were studied. KIT-6 plays a vital role in this method through immobilizing GOx and facilitating the electron communication between the active centers of GOx and the surface of the SPE. GOx immobilized on KIT-6 maintains its bioactivity and structure and displays stable and well-defined redox peaks with a formal potential of -428 mV (vs. Saturated Calomel Electrode), with a heterogeneous electron transfer rate constant of 4.15 s(-1) in phosphate buffer (0.05 M, pH 6.0). Upon the addition of glucose into air-saturated phosphate buffer solution, the reduction peak current decreases, which can be used analytically for glucose detection. The biosensor exhibits a linear response to glucose concentration ranging from 0 to 2.83 mM and a sensitivity of 7.29 microA (mM)(-1) cm(-2) at an applied potential of -0.5 V. The present work provides a promising strategy for fabricating a novel and disposable mediator-free glucose biosensor, which could be potentially mass-produced through further development.
authors.affiliation: Research Center of Analysis and Test and Institute of Advanced Materials, East China University of Science and Technology, Shanghai 200237, PR China.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Zuo
authors.forename: Xianbo
authors.initials: X
authors.lastname: Wu
authors.forename: Yuanjie
authors.initials: Y
authors.lastname: Teng
authors.forename: Huihui
authors.initials: H
authors.lastname: Yuan
authors.forename: Minbo
authors.initials: M
authors.lastname: Lan
authors.forename: Geoffrey A
authors.initials: GA
authors.lastname: Lawrance
authors.forename: Gang
authors.initials: G
authors.lastname: Wei
mesh_terms: D000327:Adsorption; D004566:Electrodes; D004583:Electrons; D004800:Enzymes, Immobilized / Q000737:chemistry*; D005949:Glucose Oxidase / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D012822:Silicon Dioxide / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D004800:Enzymes, Immobilized; D012822:Silicon Dioxide; D005949:Glucose Oxidase