Improving the Plasmon Ruler, Ultrauniform Nanoparticles to Measure Liposome Surfaces

By Olivia Hess, Biochemistry Advisor: Laura Sagle Presentation ID: PM_D07 Abstract: Liposomes are spherical lipids that are typically used in drug delivery systems and cell models. The study of nanoparticles and how they affect cells as well as being incorporated into drug delivery systems has seen increased study. The mechanisms by which these nanoparticles interact with the lipisome surfaces are not fully understood. It is the goal of this research to measure the distance between nanoparticles on the surface of a liposome, thereby elucidating the dynamics of the interaction. One way that a measurement of distance between two nanoparticles has been obtained is using a plasmonic ruler. With these rulers, distances between nanoparticles can be assigned with specific wavelengths related to the nanoparticles' plasmon coupling (i.e distance). A common method to form a plasmon ruler is by assembling alternating polyelectrolyte layers of positive and negative charges on thin gold slides. Plasmon coupling between nanoparticles and the surfaces of increasing layer sizes can then be studied, and their wavelengths are compiled on a calibration curve. In this project, we hoped to improve upon this method by using ultrauniform nanoparticles for the formation of our plasmon ruler. Ultrauniform nanoparticles are virtually identical in diameter and shape, when compared to other commercially available options which can vary a bit in these aspects. This presentation will compare the calibration curves from ultrauniform- and commercially available- nanoparticle layered samples to determine if this change creates a more precise plasmon ruler for nanoparticle measurements.