Affordable Access

deepdyve-link deepdyve-link
Publisher Website

The enzymatic oxidation of graphene oxide.

Authors
  • Kotchey, Gregg P
  • Allen, Brett L
  • Vedala, Harindra
  • Yanamala, Naveena
  • Kapralov, Alexander A
  • Tyurina, Yulia Y
  • Klein-Seetharaman, Judith
  • Kagan, Valerian E
  • Star, Alexander
Type
Published Article
Journal
ACS Nano
Publisher
American Chemical Society
Publication Date
Mar 22, 2011
Volume
5
Issue
3
Pages
2098–2108
Identifiers
DOI: 10.1021/nn103265h
PMID: 21344859
Source
Medline
License
Unknown

Abstract

Two-dimensional graphitic carbon is a new material with many emerging applications, and studying its chemical properties is an important goal. Here, we reported a new phenomenon--the enzymatic oxidation of a single layer of graphitic carbon by horseradish peroxidase (HRP). In the presence of low concentrations of hydrogen peroxide (∼40 μM), HRP catalyzed the oxidation of graphene oxide, which resulted in the formation of holes on its basal plane. During the same period of analysis, HRP failed to oxidize chemically reduced graphene oxide (RGO). The enzymatic oxidation was characterized by Raman, ultraviolet-visible, electron paramagnetic resonance, Fourier transform infrared spectroscopy, transmission electron microscopy, atomic force microscopy, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and gas chromatography-mass spectrometry. Computational docking studies indicated that HRP was preferentially bound to the basal plane rather than the edge for both graphene oxide and RGO. Owing to the more dynamic nature of HRP on graphene oxide, the heme active site of HRP was in closer proximity to graphene oxide compared to RGO, thereby facilitating the oxidation of the basal plane of graphene oxide. We also studied the electronic properties of the reduced intermediate product, holey reduced graphene oxide (hRGO), using field-effect transistor (FET) measurements. While RGO exhibited a V-shaped transfer characteristic similar to a single layer of graphene that was attributed to its zero band gap, hRGO demonstrated a p-type semiconducting behavior with a positive shift in the Dirac points. This p-type behavior rendered hRGO, which can be conceptualized as interconnected graphene nanoribbons, as a potentially attractive material for FET sensors.

Report this publication

Statistics

Seen <100 times