Achievement

Lindsey Anderson focused on quantifying the scattering cross sections of gold nanoparticles by dark-field microscopy. This requires both experimental measurements and theoretical calculations. Dark-field microscopy (DFM) measurements of single gold nanospheres where compared to the differential scattering cross section given by Mie theory for the solid angle of the detector. A wavelength-dependent constant relating the two was obtained. This constant was then used to calculate the scattering cross sections of arbitrarily shaped nanoparticles from DFM measurements. Results show that angular scattering dependence is of great importance. For the same volume, elongated particles have larger total scattering cross sections, but because of symmetry breaking, actually have smaller differential scattering cross sections for the solid angle of the DFM objective lens. Lindsey is now working on understanding angular scattering patterns of elongated particles through theoretical calculations.