Achievement

A collaborative research project involving trainee Sarah Stranahan, and others in the Willets group, showed that surface-enhanced Raman scattering (SERS) from molecules adsorbed to metal nanoparticle dimers have characteristic emission patterns that rapidly allow the orientation of the dimer to be identified. This all-optical approach for structure determination was shown to have a dependence on excitation wavelength, allowing nanoparticle dimers to be discriminated from higher order aggregates, such as trimers. While there is significant effort and interest in making controlled nanostructures for SERS, characterizing these structures typically requires time-consuming and potentially perturbative approaches such as atomic force microscopy or electron microscopy. Using our all-optical approach, researchers can now access structure information quickly and without sample damage. The research was published in J. Phys. Chem. Lett., 2011, 2, 2711¬2715 and ACS Nano, 2012, 6, 1806¬1813.