Simultaneous electrochemical detection of multiple biomarkers using gold nanoparticles decorated multiwall carbon nanotubes as signal enhancers

Anal Biochem. 2015 Aug 1;482:48-54. doi: 10.1016/j.ab.2015.04.018. Epub 2015 Apr 22.


In this work, a novel sandwich-type electrochemical immunosensor has been developed for simultaneous detection of carcinoembryonic antigen (CEA) and α-fetoprotein (AFP) based on metal ion labels. Gold nanoparticles decorated multiwall carbon nanotubes (AuNPs@MWCNTs) were used as carriers to immobilize secondary antibodies and distinguishable electrochemical tags of Pb(2+) and Cd(2+) to amplify the signals. Due to the intrinsic property of high surface-to-volume ratio, the AuNPs@MWCNTs could load numerous secondary antibodies and labels. Therefore, the multiplexed immunoassay exhibited good sensitivity and selectivity. Experimental results revealed that this sandwich-type immunoassay displayed an excellent linear response, with a linear range of 0.01 to 60 ng mL(-1) for both analytes and detection limits of 3.0 pg mL(-1) for CEA and 4.5 pg mL(-1) for AFP (at a signal-to-noise ratio of 3). The method was successfully applied for the determination of AFP and CEA levels in clinical serum samples.

Keywords: Carcinoembryonic antigen; Gold nanoparticles decorated multiwall carbon nanotubes; Multiplex assay; Pb(2+) and Cd(2+); α-Fetoprotein.

Publication types

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

MeSH terms

  • Antibodies, Immobilized / chemistry*
  • Biomarkers / analysis
  • Biomarkers / blood
  • Cadmium / chemistry
  • Carcinoembryonic Antigen / blood*
  • Cations, Divalent / chemistry
  • Electrochemical Techniques / methods*
  • Gold / chemistry*
  • Humans
  • Immunoassay / methods
  • Lead / chemistry
  • Limit of Detection
  • Metal Nanoparticles / chemistry*
  • Metal Nanoparticles / ultrastructure
  • Nanotubes, Carbon / chemistry*
  • Nanotubes, Carbon / ultrastructure
  • alpha-Fetoproteins / analysis*


  • Antibodies, Immobilized
  • Biomarkers
  • Carcinoembryonic Antigen
  • Cations, Divalent
  • Nanotubes, Carbon
  • alpha-Fetoproteins
  • Cadmium
  • Lead
  • Gold