Graphene/Quantum Dot Bionanoconjugates as Signal Amplifiers in Stripping Voltammetric Detection of EpCAM Biomarkers
Author(s)
Shiddiky, Muhammad JA
Rauf, Sakandar
Kithva, Prakash H
Trau, Matt
Griffith University Author(s)
Year published
2012
Metadata
Show full item recordAbstract
A sensitive electrochemical immunosensor for the detection of epithelial cell adhesion molecule (EpCAM) antigen, a common marker for tumors of epithelial origin, employing bionanoconjugates as signal-transduction labels has been developed. The bionanoconjugates were fabricated by carboxylation of the two-dimensional graphene oxide nanosheets (GRs) and immobilizing streptavidin and amine-functionalized CdSe quantum dots (QDs) on carboxylated GRs via carbodiimide coupling chemistry, followed by the immunoreaction with the biotinylated secondary antibodies. Since carboxylated GRs have a higher density of active sites, it allows ...
View more >A sensitive electrochemical immunosensor for the detection of epithelial cell adhesion molecule (EpCAM) antigen, a common marker for tumors of epithelial origin, employing bionanoconjugates as signal-transduction labels has been developed. The bionanoconjugates were fabricated by carboxylation of the two-dimensional graphene oxide nanosheets (GRs) and immobilizing streptavidin and amine-functionalized CdSe quantum dots (QDs) on carboxylated GRs via carbodiimide coupling chemistry, followed by the immunoreaction with the biotinylated secondary antibodies. Since carboxylated GRs have a higher density of active sites, it allows a large number of CdSe QDs to be immobilized onto the surface of the bionanoconjugates, and hence, enhance the sensitivity of the immunosensor. The method enabled detection limits of 100 fg/mL and 1 pg/mL (based on the S/N = 3) in PBS buffer and serum samples, respectively, using anodic stripping voltammetric readout. The immunosensor showed a good selectivity, reproducibility, and long-storage stability, and may become a promising technique for the early detection of tumor biomarker in clinical/biological samples.
View less >
View more >A sensitive electrochemical immunosensor for the detection of epithelial cell adhesion molecule (EpCAM) antigen, a common marker for tumors of epithelial origin, employing bionanoconjugates as signal-transduction labels has been developed. The bionanoconjugates were fabricated by carboxylation of the two-dimensional graphene oxide nanosheets (GRs) and immobilizing streptavidin and amine-functionalized CdSe quantum dots (QDs) on carboxylated GRs via carbodiimide coupling chemistry, followed by the immunoreaction with the biotinylated secondary antibodies. Since carboxylated GRs have a higher density of active sites, it allows a large number of CdSe QDs to be immobilized onto the surface of the bionanoconjugates, and hence, enhance the sensitivity of the immunosensor. The method enabled detection limits of 100 fg/mL and 1 pg/mL (based on the S/N = 3) in PBS buffer and serum samples, respectively, using anodic stripping voltammetric readout. The immunosensor showed a good selectivity, reproducibility, and long-storage stability, and may become a promising technique for the early detection of tumor biomarker in clinical/biological samples.
View less >
Journal Title
Biosensors and Bioelectronics
Volume
35
Issue
1
Subject
Analytical chemistry
Analytical chemistry not elsewhere classified
Biomedical engineering
Nanotechnology