Immunoassay using the probe-labeled Au/Ag core-shell nanoparticles based on surface-enhanced Raman scattering

Au/Ag core-shell nanoparticles labeled by monoclonal antibody and surface-enhanced Raman scattering (SERS) probes were used for immunoassay analysis. Mouse polyclonal antibodies against hepatitis B surface antigen (mouse Anti-HBsAg PAb) were covalently immobilized on the silicon chips modified by a self-assembled monolayer of (3-amino-propyl) trimethoxysilane via glutaraldehyde (GA) activation. The Au/Ag core-shell nanoparticles were labeled by the mouse monoclonal antibody against hepatitis B surface antigen (mouse Anti-HBsAg MAb) and the probe molecule, p-mercaptobenzoic acid (MBA). Immunoreactions between the labeled Au/Ag core-shell nanoparticles and the corresponding antigens captured by the Anti-HBsAg PAb on the silicon chips were investigated by SERS.