Effect of silver nanoparticles on the electron transfer reactivity and the catalytic activity of myoglobin

Xin Gan, Tao Liu, Jun Zhong, Xinjian Liu, Genxi Li

Research output: Contribution to journalArticlepeer-review

Abstract

Silver nanoparticles (11 ± 1.5 nm) could greatly enhance the electron-transfer reactivity of myoglobin (Mb) and its catalytic ability toward hydrogen peroxide (H2O2). Direct fast electron transfer between Mb and a pyrolytic graphite (PG) electrode was achieved, and a pair of well-defined, quasireversible redox peaks was obtained. The cathodic and anodic peaks were located at -329 and -281 mV, respectively. Meanwhile, the catalytic ability of the protein toward the reduction of H2O2 was also studied, and a H2O2 biosensor was subsequently fabricated. Its detection limit was 1.0 × 10-6M with a sensitivity of 0.0205 μA per μM of H2O2. The apparent Michaelis-Menten constant was calculated to be 1303 μM. Flocculation assay showed that the protein maintained plasmon layers surrounding the surface of silver nanoparticles and avoided silver-nanopartkle aggregation. On the other hand, UV-visible spectroscopy studies revealed that silver nanoparticles could induce a small change of the heme-group environment of the protein; this contributed to the enhancement of the electron-transfer reactivity and the catalytic activity.

Original languageEnglish (US)
Pages (from-to)1686-1691
Number of pages6
JournalChemBioChem
Volume5
Issue number12
DOIs
StatePublished - 2004

Keywords

  • Electrochemistry
  • Electrodes
  • Myoglobin
  • Nanoparticles
  • Silver

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Medicine
  • Molecular Biology
  • Organic Chemistry

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