Professor Catherine J. Murphy of the University of Illinois

"Gold Nanocrystals: Physics, Chemistry, Biology, and Ecology"

"Gold nanocrystals of controlled size and shape have tunable optical properties that enable new science. Upon illumination with resonant light, these gold nanocrystals generate plasmons (coherent oscillations of conduction band electrons). These plasmons, in turn, can produce local electric fields and heat. In this talk I will discuss four short stories about gold nanocrystals and their plasmons. In “Physics” we will discuss how molecules experience the local electric field provided by illuminated plasmonic nanorods, how plasmonic heat can lead to molecular adsorption and desorption, and show new data about photoelectron emission from nanorods under high laser powers. In “Chemistry” we will discuss how the surface chemistry of the nanocrystals can be tuned with both hard and soft shells, quantified at sub-1nm-length scales, and how the particular chemistry at the surface dictates molecular function. In “Biology” I will discuss how these nanocrystals interact with biological fluids and living cells; and in “Ecology” I will discuss how these nanoparticles are distributed in an estuarine ecosystem as a function of surface chemistry."