title: Entrapment of enzymes and carbon nanotubes in biologically synthesized silica: glucose oxidase-catalyzed direct electron transfer.
abstract: This work demonstrates a new approach for building bioinorganic interfaces by integrating biologically derived silica with single-walled carbon nanotubes to create a conductive matrix for immobilization of enzymes. Such a strategy not only allows simple integration into biodevices but presents an opportunity to intimately interface an enzyme and manifest direct electron transfer features. Biologically synthesized silica/carbon nanotube/enzyme composites are evaluated electrochemically and characterized by means of X-ray photoelectron spectroscopy. Voltammetry of the composites displayed stable oxidation and reduction peaks at an optimal potential close to that of the FAD/FADH(2) cofactor of immobilized glucose oxidase. The immobilized enzyme is stable for a period of one month and retains catalytic activity for the oxidation of glucose. It is demonstrated that the resulting composite can be successfully integrated into functional bioelectrodes for biosensor and biofuel cell applications.
authors.affiliation: Chemical and Nuclear Engineering Department, University of New Mexico, Albuquerque, NM 87131, USA.
authors.forename: Dmitri
authors.initials: D
authors.lastname: Ivnitski
authors.forename: Kateryna
authors.initials: K
authors.lastname: Artyushkova
authors.forename: Rosalba A
authors.initials: RA
authors.lastname: Rincón
authors.forename: Plamen
authors.initials: P
authors.lastname: Atanassov
authors.forename: Heather R
authors.initials: HR
authors.lastname: Luckarift
authors.forename: Glenn R
authors.initials: GR
authors.lastname: Johnson
mesh_terms: D004579:Electron Transport; D004800:Enzymes, Immobilized / Q000378:metabolism*; D005949:Glucose Oxidase / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D037742:Nanotubes, Carbon; D012822:Silicon Dioxide / Q000378:metabolism*; D013057:Spectrum Analysis; D014965:X-Rays
chemical_list: D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D012822:Silicon Dioxide; D005949:Glucose Oxidase