A sandwich-type DNA biosensor based on electrochemical co-reduction synthesis of graphene-three dimensional nanostructure gold nanocomposite films

Anal Chim Acta. 2013 Mar 12:767:50-8. doi: 10.1016/j.aca.2012.12.049. Epub 2013 Jan 8.

Abstract

A novel electrochemical DNA biosensor based on graphene-three dimensional nanostructure gold nanocomposite modified glassy carbon electrode (G-3D Au/GCE) was fabricated for detection of survivin gene which was correlated with osteosarcoma. The G-3D Au film was prepared with one-step electrochemical coreduction with graphite oxide and HAuCl4 at cathodic potentials. The active surface area of G-3D Au/GCE was 2.629cm(2), which was about 3.8 times compared to that of a Au-coated GCE under the same experimental conditions, and 8.8 times compared to a planar gold electrode with a similar geometric area. The resultant nanocomposites with high conductivity, electrocatalysis and biocompatibility were characterized by scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). A "sandwich-type" detection strategy was employed in this electrochemical DNA biosensor and the response of this DNA biosensor was measured by CV and amperometric current-time curve detection. Under optimum conditions, there was a good linear relationship between the current signal and the logarithmic function of complementary DNA concentration in a range of 50-5000fM with a detection limit of 3.4fM. This new biosensor exhibited a fast amperometric response, high sensitivity and selectivity and has been used in a polymerase chain reaction assay of real-life sample with a satisfactory result.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biosensing Techniques*
  • DNA / analysis*
  • Electrochemical Techniques*
  • Electrodes
  • Gold / chemistry*
  • Graphite / chemistry*
  • Metal Nanoparticles / chemistry*
  • Microscopy, Electron, Scanning
  • Osteosarcoma / genetics*
  • Oxidation-Reduction
  • Oxides / chemistry

Substances

  • Oxides
  • Gold
  • Graphite
  • DNA