Manipulation of gold nanorod surfaces with self-assembled monolayers

Gold nanorods exhibit spectral peaks due to localized surface plasmon resonances (LSPR) which are sensitive to the optical properties of their environment. Accordingly, molecular binding to the surface of gold nanorods generates a shift in the spectral peak. In addition, self-assembled monolayers (SAMs) with well-defined and controllable molecular architectures on gold nanorod surfaces enable us to create a gold nanorod biosensor based on LSPR. We have demonstrated a simple immunoassay based on LSPR of gold nanorods. Here we report on the optimization of SAMs on gold nanorods for sensing applications, and on the kinetics of their formation, etching, and molecular displacement on gold nanorod surfaces.