Analytical and Bioanalytical Chemistry

, Volume 387, Issue 4, pp 1565–1572

Effect of silica nanoparticles with different sizes on the catalytic activity of glucose oxidase

  • Yingying Sun
  • Feng Yan
  • Weiwei Yang
  • Shuang Zhao
  • Wensheng Yang
  • Changqing Sun
Technical Note

Abstract

In this work we present a strategy for the covalent immobilization of periodate oxidized glucose oxidase (\( {\text{IO}}^{ - }_{4} {\text{ - GOx}} \)) to aminated silica nanoparticles (ASNPs) modified on gold electrodes. Silica nanoparticles greatly enhanced the catalytic ability of GOx toward the oxidation of glucose and improved the electron transfer between the GOx and the electrode surface. ASNPs of varying size—that is 100, 80, 60, and 30 nm—were prepared, and they were used to fabricate biosensors. Electrochemical impedance spectroscopy (EIS) of ferrocyanide followed the assembly process and verified the successful immobilization of \( {\text{IO}}^{ - }_{4} {\text{ - GOx}} \) on ASNPs modified on gold electrodes. From the analysis of catalytic signals of biosensors using different sizes of ASNPs under the same conditions, the surface concentration of electrically wired enzyme (ΓET) was estimated and was found to increase with decreasing ASNPs size. Therefore, the sensitivity of biosensors using smaller ASNPs was higher than that using larger particles. Specifically, we utilized the ASNPs with optimal size (30 nm) to fabricate the glucose biosensor. The resulting electrodes showed a wide linear response to glucose at least to 6 mM and reached 95% of the steady-state current in less than 4 s with a sensitivity of 5.02 μA mM−1 cm−2 and a detection limit of 0.01 mM. The biosensor also showed excellent stability and good reproducibility.

Keywords

Glucose oxidase Aminated silica nanoparticles Covalent attachment Biosensors 

Supplementary material

216_2006_1013_MOESM1_ESM.doc (601 kb)
(DOC 615kb)

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Yingying Sun
    • 1
  • Feng Yan
    • 1
  • Weiwei Yang
    • 1
  • Shuang Zhao
    • 1
  • Wensheng Yang
    • 1
  • Changqing Sun
    • 1
  1. 1.College of ChemistryJilin UniversityChangchunChina

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