Single-crystal CeO2 nanocubes used for the direct electron transfer and electrocatalysis of horseradish peroxidase

Biosens Bioelectron. 2009 Apr 15;24(8):2447-51. doi: 10.1016/j.bios.2008.12.020. Epub 2008 Dec 25.

Abstract

A new horseradish peroxidase (HRP) third-generation electrochemical biosensor based on ceria nanocubes (CeO(2)-NCs) and chitosan (Chit) was developed. The single-crystalline, uniform and size-controlled CeO(2)-NCs have been synthesized by hydrothermal method. HRP was immobilized in CeO(2)-NCs and Chit film on the glass carbon electrode (HRP/CeO(2)/Chit/GCE). Compared with HRP-chitosan modified electrode (HRP/Chit/GCE), HRP/CeO(2)/Chit/GCE exhibited a pair of more obvious redox peaks at -0.348 V (versus Ag/AgCl). Experimental results indicate CeO(2)-NCs greatly promoted the electron transfer between HRP and GCE. The immobilized HRP exhibited direct electrochemical behavior toward the reduction of hydrogen peroxide (H(2)O(2)). The resulting biosensor showed a linear range of 1-150 microM and a detection limit of 0.26 microM estimated at a signal-to-noise ratio of 3. Stability and reproducibility of the biosensor were also studied. The biological activity of HRP immobilizing in the composite film was characterized by UV-vis and FTIR spectra.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biosensing Techniques / instrumentation*
  • Biosensing Techniques / methods
  • Catalysis
  • Cerium / chemistry*
  • Crystallization / methods
  • Electrochemistry / instrumentation*
  • Electrochemistry / methods
  • Electron Transport
  • Equipment Design
  • Equipment Failure Analysis
  • Horseradish Peroxidase / analysis*
  • Horseradish Peroxidase / chemistry*
  • Nanostructures / chemistry*
  • Nanostructures / ultrastructure
  • Nanotechnology / instrumentation*
  • Nanotechnology / methods
  • Reproducibility of Results
  • Sensitivity and Specificity

Substances

  • Cerium
  • ceric oxide
  • Horseradish Peroxidase