Ultrasensitive electrochemiluminescence immunoassay for tumor marker detection using functionalized Ru-silica@nanoporous gold composite as labels

Analyst. 2012 Feb 7;137(3):680-5. doi: 10.1039/c1an15942a. Epub 2011 Dec 7.

Abstract

In this work, we reported a simple and sensitive sandwich-type electrochemiluminescence (ECL) immunosensor for carcinoembryonic antigen (CEA) on a gold nanoparticles (AuNPs) modified glassy carbon electrode (GCE). The Ru-silica (Ru(bpy)(3)(2+)-doped silica) capped nanoporous gold (NPG) (Ru-silica@NPG) composite was used as an excellent label with amplification techniques. The NPG was prepared with a simple dealloying strategy, by which silver was dissolved from silver/gold alloys in nitric acid. The primary antibody was immobilized on the AuNPs modified electrode through l-cysteine and glutaraldehyde, and then the antigen and the functionalized Ru-silica@NPG composite labeled secondary antibody were conjugated successively to form a sandwich-type immunocomplex through the specific interaction. The concentrations of CEA were obtained in the range from 1 pg mL(-1) to 10 ng mL(-1) with a detection limit of 0.8 pg mL(-1). The as-proposed ECL immunosensor has the advantages of high sensitivity, specificity and stability and could become a promising technique for tumor marker detection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers, Tumor / analysis*
  • Biosensing Techniques
  • Carcinoembryonic Antigen / analysis
  • Dielectric Spectroscopy
  • Electrochemistry / methods*
  • Gold / chemistry*
  • Immunoassay / methods*
  • Limit of Detection
  • Luminescence*
  • Metal Nanoparticles*
  • Reproducibility of Results
  • Ruthenium / chemistry*
  • Silicon Dioxide / chemistry*

Substances

  • Biomarkers, Tumor
  • Carcinoembryonic Antigen
  • Gold
  • Silicon Dioxide
  • Ruthenium