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Journal of Nanomaterials
Volume 2016, Article ID 7834657, 8 pages
http://dx.doi.org/10.1155/2016/7834657
Research Article

Label-Free Detection of Chondroitin Sulphate Proteoglycan 4 by a Polyaniline/Graphene Nanocomposite Functionalized Impedimetric Immunosensor

1Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, Chongqing 400715, China
2Institute for Clean Energy & Advanced Materials, Faculty of Materials and Energy, Southwest University, Chongqing 400715, China
3Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA

Received 19 November 2015; Accepted 11 January 2016

Academic Editor: Hassan Karimi-Maleh

Copyright © 2016 JingJing Fu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The chondroitin sulphate proteoglycan 4 (CSPG4), also known as high molecular weight-melanoma associated antigen (HMW-MAA), is a tumor-associated antigen that is expressed in more than 85% of surgically removed melanoma lesions but has restricted distribution in normal tissues. The diagnostic and therapeutic value of CSPG4 drives a need for sensitive and low-cost detection approaches. To this end, we developed a polyaniline/graphene oxide nanocomposite (PANI@GO) that was electrochemically codeposited on indium tin oxide (ITO) electrode. Glutaraldehyde mediated the covalent immobilization of CSPG4 specific antibody mAbD2.8.5 to construct a CSPG4 immunosensor using cell culture media and cell lysate as samples. The fully assembled impedimetric immunosensor was used to detect CSPG4 in CSPG4-positive cell lines M14/CSPG4 and MV3. No impedance signal changes could be observed from CSPG4-negative cell lines M14 and mAbMk2-23 showing the specificity of the CSPG4-impedimetric immunosensor. This low-cost, simple, and label-free analytical method is an alternative to enzyme-linked immunosorbent assay and flow cytometry in screening of CSPG4 in complex biological samples.