Detection of biomolecules using light scattering

In this paper, a straightforward method based on elastic light scattering is shown to provide a sensitive and reliable tool for the quantitative determination of receptor-ligand interactions that occur at the surface of suitably designed core-shell nanoparticles. The assay makes use of monodisperse nanocolloids that have minimal optical contrast with the aqueous environment. By properly coating the particles with an appropriate receptor and unreactive amphiphiles, we developed a hybrid system that combines the availability of standard ligands with the necessary bioinvisibility towards the accidental adsorption of nonspecific macromolecules. This system has been used for the study of the interactions between small molecules (Vancomycin - Lipid 2), and between proteins (Avidin - biotinnylated IgG.