A novel nitrite biosensor based on gold dendrites with egg white as template

Anal Sci. 2012;28(4):403-9. doi: 10.2116/analsci.28.403.

Abstract

Gold dendrites (AuD) were synthesized with egg white as the soft template and a novel nitrite (NO(2)(-)) biosensor was fabricated by assembly of a myoglobin (Mb)-L-cysteamine (Cys)-AuD biological hybrid. The results of Fourier transform infrared spectra and UV-visible spectra indicated that Mb retained its original structure in the resulting Mb-Cys-AuD. Electrochemical investigation of the biosensor showed a pair of well-defined, quasi-reversible redox peaks with E(pa) = -0.314 V and E(pc) = -0.344 V (vs. SCE) in 0.1 M, pH 7.0 sodium phosphate buffered saline at the scan rate of 200 mV/s. The transfer rate constant (k(s)) was 1.49 s(-1). The Mb-Cys-AuD showed a good electrochemical catalytic response for the reduction of NO(2)(-), with the linear range from 0.5 to 400 µM and the detection limit of 0.3 µM (S/N = 3). The apparent Michaelis-Menten constant (K(M)(app)) was estimated to be 0.2 mM. Therefore, the assembled bio-hybrid as a novel matrix opened up a further possibility for study on the design of enzymatic biosensors with potential applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biosensing Techniques*
  • Cattle
  • Chemistry Techniques, Analytical
  • Egg White / chemistry
  • Electrochemistry / methods*
  • Electrodes
  • Gold / chemistry*
  • Kinetics
  • Myoglobin / chemistry
  • Nitrites / chemistry*
  • Oxidation-Reduction
  • Spectroscopy, Fourier Transform Infrared / methods

Substances

  • Myoglobin
  • Nitrites
  • Gold