Entrapment of enzymes and carbon nanotubes in biologically synthesized silica: glucose oxidase-catalyzed direct electron transfer.
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.
Ivnitski
Dmitri
D
Chemical and Nuclear Engineering Department, University of New Mexico, Albuquerque, NM 87131, USA.
Artyushkova
Kateryna
K
Rincón
Rosalba A
RA
Atanassov
Plamen
P
Luckarift
Heather R
HR
Johnson
Glenn R
GR
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
D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D012822:Silicon Dioxide; D005949:Glucose Oxidase