title: Attomolar detection of protein biomarkers using biofunctionalized gold nanorods with surface plasmon resonance.
abstract: This paper describes an ultrasensitive surface plasmon resonance (SPR) detection method using biofunctionalized gold nanorods for the direct detection of protein biomarkers. Immunoglobulin E (IgE), which has separate antibody and DNA aptamer binding sites, was chosen as a model protein for which a sandwich assay platform was designed. Detection was achieved via the specific adsorption of unlabelled IgE proteins onto the surface immobilized aptamer followed by the specific adsorption of anti-IgE coated gold nanorods (Au-NRs). Using the biofunctionalized nanorods in conjunction with SPR, we were able to directly measure IgE proteins at attomolar concentrations. This is a remarkable 10(8) enhancement compared to conventional SPR measurements of the same surface sandwich assay format 'anti-IgE/IgE/surface bound IgE-aptamer' in the absence of gold nanorod signal amplification.
authors: Department of Chemistry, Kyungpook National University, 1370 Sankyuk-dong, Buk-gu, Daegu-city, 702-701, Republic of Korea.
authors: Hye Rim
authors: HR
authors: Sim
authors: Alastair W
authors: AW
authors: Wark
authors: Hye Jin
authors: HJ
authors: Lee
mesh_terms: D055910:Antibodies, Immobilized / Q000276:immunology; D052157:Aptamers, Nucleotide / Q000737:chemistry; D001665:Binding Sites; D015415:Biomarkers / Q000032:analysis; D006046:Gold / Q000737:chemistry*; D007073:Immunoglobulin E / Q000032:analysis*; D043942:Nanotubes / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D055910:Antibodies, Immobilized; D052157:Aptamers, Nucleotide; D015415:Biomarkers; D007073:Immunoglobulin E; D006046:Gold