Dual-Wavelength Surface Plasmon Resonance for Determining the Size and Concentration of Sub-Populations of Extracellular Vesicles
Journal article, 2016

Accurate concentration determination of subpopulations of extracellular vesicles (EVs), such as exosomes, is of importance both in the context of understanding their fundamental biological role and of potentially using them as disease biomarkers. In principle, this can be achieved by measuring the rate of diffusion-limited mass uptake to a sensor surface modified with a receptor designed to only bind the subpopulation of interest. However, a significant error is introduced if the targeted EV subpopulation has a size, and thus hydrodynamic diffusion coefficient, that differs from the mean size and diffusion coefficient of the whole EV population and/or if the EVs become deformed upon binding to the surface. We here demonstrate a new approach to determine the mean size (or effective film thickness) of bound nanoparticles, in general, and EV subpopulation carrying a marker of interest, in particular. The method is based on operating surface plasmon resonance simultaneously at two wavelengths with different sensing depths and using the ratio of the corresponding responses to extract the particle size on the surface. By estimating in this way the degree of deformation of adsorbed EVs, we markedly improved their bulk concentration determination and showed that EVs carrying the exosomal marker CD63 correspond to not more than around 10% of the EV sample.

Dual-Wavelength Surface Plasmon Resonance

Extracellular Vesicles

Author

Deborah Rupert

Chalmers, Physics, Biological Physics

Ganesh V Shelke

University of Gothenburg

Gustav Emilsson

Chalmers, Physics, Bionanophotonics

Virginia Claudio

Chalmers, Physics, Biological Physics

Stephan Block

Chalmers, Physics, Biological Physics

Cecilia Lässer

University of Gothenburg

Andreas Dahlin

Chalmers, Physics, Bionanophotonics

Jan Lötvall

University of Gothenburg

Marta Bally

Chalmers, Physics, Biological Physics

Vladimir Zhdanov

Chalmers, Physics, Chemical Physics

Fredrik Höök

Chalmers, Physics, Biological Physics

Analytical Chemistry

0003-2700 (ISSN) 1520-6882 (eISSN)

Vol. 88 20 9980-9988

Subject Categories

Cell Biology

Nano Technology

DOI

10.1021/acs.analchem.6b01860

More information

Created

10/8/2017