title: Refractive index determination of nanoparticles in suspension using nanoparticle tracking analysis.
abstract: The refractive index (RI) dictates interaction between light and nanoparticles and therefore is important to health, environmental, and materials sciences. Using nanoparticle tracking analysis, we have determined the RI of heterogeneous particles <500 nm in suspension. We demonstrate feasibility of distinguishing silica and polystyrene beads based on their RI. The hitherto unknown RI of extracellular vesicles from human urine was determined at 1.37 (mean). This method enables differentiation of single nanoparticles based on their RI.
authors.affiliation: Biomedical Engineering and Physics, ‡ Laboratory of Experimental Clinical Chemistry, Academic Medical Center, University of Amsterdam , Amsterdam, The Netherlands.
authors.forename: Edwin
authors.initials: E
authors.lastname: van der Pol
authors.forename: Frank A W
authors.initials: FA
authors.lastname: Coumans
authors.forename: Auguste
authors.initials: A
authors.lastname: Sturk
authors.forename: Rienk
authors.initials: R
authors.lastname: Nieuwland
authors.forename: Ton G
authors.initials: TG
authors.lastname: van Leeuwen
keywords: Drug delivery; exosomes; extracellular vesicles; microparticles; nanomedicine; nanoparticles