Protein–ligand binding investigated by a single nanoparticle TERS approach

We report TERS imaging of individual 50 nm, biotin-labeled gold nanoparticles bound to a streptavidin-derivatized glass slide. Individual gold nanoparticles detected by a nanoparticle TERS tip generate Raman enhancements in both the biotin and streptavidin signals. These results indicate that nanoparticles are capable of investigating nanoscale spatial and chemical environments with non-resonant Raman enhancements.