Ultralow Detection of Bio-markers using Gold Nanoshells

use of Gold nanoparticles (AuNPs) as identification markers or labels, allows for detection of antigens, analytes, biomarkers, or viral particles, in small sample volumes and concentrations in a very sensitive and specific environment. The focus of this project is to improve the detection of antigen/biomarkers/viral vectors using gold nanoshells (GNS). The assay used in this project is based on aggregation of GNS in presence of antigen or viral vectors. GNS are coated with thiolated poly(ethylene) glycol amine (HS-PEG-NH2)-conjugated Protein G (ProG) and Goat anti-rabbit antibody. Our data shows that fully assembled nanoparticles in presence of antigen, rabbit IgG (Rb IgG), allow detection events at concentrations in the ng/ml to pg/ml range. The lower detection limit of this improved assay was 0.5 pg/mL, within 10 mins. This shows a 3 order of magnitude improvement over that previously reported.