Refractive index determination of nanoparticles in suspension using nanoparticle tracking analysis

Nano Lett. 2014 Nov 12;14(11):6195-201. doi: 10.1021/nl503371p. Epub 2014 Oct 2.


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.

Keywords: Drug delivery; exosomes; extracellular vesicles; microparticles; nanomedicine; nanoparticles.

Publication types

  • Research Support, Non-U.S. Gov't