Ultrasensitive sandwich-type electrochemical immunosensor based on trimetallic nanocomposite signal amplification strategy for the ultrasensitive detection of CEA

Sci Rep. 2016 Aug 4:6:30849. doi: 10.1038/srep30849.

Abstract

A novel and ultrasensitive sandwich-type electrochemical immunosensor was designed for the quantitative detection of carcino-embryonic antigen (CEA). This immunosensor was developed by using the trimetallic NiAuPt nanoparticles on graphene nanosheets (NGs) nanosheets (NiAuPt-NGs) as excellent labels and β-cyclodextrin functionalized reduced graphene oxide nanosheets (CD-NGs) as the platform. The CD-NGs with high specific surface area good biocompatibility and the ideal dispersibility was used to capture the primary antibodies (Ab1) efficiently. The trimetallic NiAuPt-NGs nanocomposites were used as the labels for signal amplification, showing better electrocatalytic activity towards the reduction of hydrogen peroxide (H2O2), which is much better than that the monometallic Pt-NGs, bimetallic NiPt-NGs and AuPt-NGs due to the synergetic effect presented in NiAuPt-NGs. The NiAuPt-NGs nanocomposites consist of tightly coupled nanostructures of Au, Ni and Pt, which have neither an alloy nor a core-shell structure. Under the optimal conditions, a linear range from 0.001-100 ng/mL and a low detection limit of 0.27 pg/mL were obtained for CEA. The proposed electrochemical sandwich-type immunosensor may have a promising application in bioassay and it enriches the electrochemical immunoassays.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Immobilized / chemistry
  • Biomarkers, Tumor / analysis*
  • Biosensing Techniques
  • Carcinoembryonic Antigen / analysis*
  • Carcinoembryonic Antigen / blood
  • Colonic Neoplasms / diagnosis*
  • Electrochemical Techniques / methods*
  • Graphite / chemistry
  • Humans
  • Hydrogen Peroxide / chemistry
  • Metal Nanoparticles / chemistry*
  • Nanocomposites / chemistry*
  • Nickel / chemistry
  • Oxidation-Reduction
  • Platinum / chemistry
  • Silver / chemistry
  • beta-Cyclodextrins / chemistry

Substances

  • Antibodies, Immobilized
  • Biomarkers, Tumor
  • Carcinoembryonic Antigen
  • beta-Cyclodextrins
  • Silver
  • Platinum
  • Graphite
  • Nickel
  • Hydrogen Peroxide
  • betadex