Optical Detection of Protein in Complex Media with Plasmonic Nanoparticle Dimers

Actuatable gold nanoparticle dimers for protein sensing are presented. By monitoring the spectral blue shift in the hybridized bonding plasmon mode instead of the conventional refractive index changes on a single nanoparticle, dimers are shown to be able to detect target protein even in the presence of high levels of nonspecific binding in complex media such as serum.