Send to:

Choose Destination
See comment in PubMed Commons below
Analyst. 2012 Oct 7;137(19):4440-7. doi: 10.1039/c2an35751h.

Ultrasensitive electrochemical immunosensor for CA 15-3 using thionine-nanoporous gold-graphene as a platform and horseradish peroxidase-encapsulated liposomes as signal amplification.

Author information

  • 1School of Chemistry & Chemical Engineering, Technology Research Center for Colloidal Materials, Shandong University, Jinan 250100, China.


This paper describes a novel electrochemical immunosensor using a nanoporous gold (NPG)/graphene (GN) hybrid platform combined with horseradish peroxidase (HRP)-encapsulated liposomes as labels for the sensitive detection of cancer antigen 15-3 (CA 15-3). The electrochemical detection was based on the released HRP from HRP-encapsulated liposomes toward the reduction of H(2)O(2) with the help of the thionine (TH) electron mediator. In the presence of CA 15-3, HRP@liposomes and TH-NPG-GN formed a sandwich-type immunocomplex, and the immunocomplex increased with the increment of the CA 15-3 concentration in the sample. The more CA 15-3 antigen in the sample there was, the more HRP@liposomes/anti-CA 15-3 in the immunocomplex there were. Thus, the catalytic current increased. Under optimized conditions, the linear range of the immunoassay is 2 × 10(-5) to 40 U mL(-1) with a detection limit of 5 × 10(-6) U mL(-1) CA 15-3. The CA 15-3 concentrations of the clinical serum specimens assayed by the developed immunoassay showed consistent results in comparison with those obtained by a commercially available electrochemiluminescence assay. This proposed immunoassay system had many desirable merits including sensitivity, accuracy, and minimal instrumentation required. Significantly, the new protocol may be quite promising, with potentially broad applications for clinical immunoassays.

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Royal Society of Chemistry
    Loading ...
    Write to the Help Desk