Surface characterization of plasmonic materials via aqueous thermal field-flow fractionation

KIM WILLIAMS

krwillia@mines.edu

Pure gold in its bulk form is known for its luster and yellow-orange color. However when gold is in a nanoparticle (<100 nm) form, it can take on nearly any color of the rainbow.  This change in color is due to a surface-based effect known as plasmon resonance (SPR) Plasmonic materials have a wide range of applications including sensing, renewable energy (solar and electrocatalysts), and cancer treatment. The size, shape, periodicity and materials environment of plasmonic materials strongly impact its performance in these applications and its characterization remains an analytical challenge. Our research group focusses on the development of field-flow fractionation (FFF), a technique which has become increasingly important for researchers seeking to understand the relationship between nanoparticles (NPs) physicochemical characteristics and observed properties and behaviors.  The FFF family of instruments is well-suited for nanomaterials because the open channel design allows the separation of species whose sizes are < 1000 nm while the applied field provides the basis for characterization. The objective of this project is to develop aqueous thermal FFF (ThFFF) for the characterization of gold nanoparticles. Bare gold NPs will be used initially to optimize carrier fluid solution compositions and instrumental conditions.  Proteins and/or polymers will be adsorbed to these gold NPs and the impact on ThFFF retention times and the SPR wavelength will be studied.  These measurements may provide invaluable information about the amount of adsorbed protein and shifts in SPR wavelengths (in addition to NP size) and ultimately yield a new technique that provides insights into the properties and behaviors of coated gold NPs.

Grand Challenge: Engineer better medicines.

Kim Williams. Michael Toney (graduate student)