Label-free quantification of protein binding to lipid vesicles using transparent waveguide evanescent-field scattering microscopy with liquid control
Artikel i vetenskaplig tidskrift, 2023

Recent innovations in microscopy techniques are paving the way for label-free studies of single nanoscopic biological entities such as viruses, lipid-nanoparticle drug carriers, and even proteins. One such technique is waveguide evanescent-field microscopy, which offers a relatively simple, yet sensitive, way of achieving label-free light scattering-based imaging of nanoparticles on surfaces. Herein, we extend the application of this technique by incorporating microfluidic liquid control and adapting the design for use with inverted microscopes by fabricating a waveguide on a transparent substrate. We furthermore formulate analytical models describing scattering and fluorescence intensities from single spherical and shell-like objects interacting with evanescent fields. The models are then applied to analyze scattering and fluorescence intensities from adsorbed polystyrene beads and to temporally resolve cholera-toxin B (CTB) binding to individual surface-immobilized glycosphingolipid GM1 containing vesicles. We also propose a self-consistent means to quantify the thickness of the CTB layer, revealing that protein-binding to individual vesicles can be characterized with sub-nm precision in a time-resolved manner.


Mokhtar Mapar

Chalmers, Fysik, Nano- och biofysik

Mattias Sjöberg

Chalmers, Fysik, Nano- och biofysik

Nanolyze AB

Vladimir Zhdanov

Chalmers, Fysik

Russian Academy of Sciences

Björn Agnarsson

Nanolyze AB

Chalmers, Fysik, Nano- och biofysik

Fredrik Höök

Chalmers, Fysik, Nano- och biofysik

Biomedical Optics Express

21567085 (eISSN)

Vol. 14 8 4003-4016

Tvådimensionell flödescytometry för analys av enskilda nanopartiklar

Vetenskapsrådet (VR) (2018-04900), 2018-12-01 -- 2021-12-31.


Fysikalisk kemi

Atom- och molekylfysik och optik


Den kondenserade materiens fysik



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