Polymer brushes in solid-state nanopores form an impenetrable entropic barrier for proteins
Journal article, 2018

Polymer brushes are widely used to prevent the adsorption of proteins, but the mechanisms by which they operate have remained heavily debated for many decades. We show conclusive evidence that a polymer brush can be a remarkably strong kinetic barrier towards proteins by using poly(ethylene glycol) grafted to the sidewalls of pores in 30 nm thin gold films. Despite consisting of about 90% water, the free coils seal apertures up to 100 nm entirely with respect to serum protein translocation, as monitored label-free through the plasmonic activity of the nanopores. The conclusions are further supported by atomic force microscopy and fluorescence microscopy. A theoretical model indicates that the brush undergoes a morphology transition to a sealing state when the ratio between the extension and the radius of curvature is approximately 0.8. The brush-sealed pores represent a new type of ultrathin filter with potential applications in bioanalytical systems.

Author

Gustav Emilsson

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Kunli Xiong

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Yusuke Sakiyama

University of Basel

Bita Malekian

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Viktor Ahlberg Gagnér

University of Gothenburg

Rafael L. Schoch

University of Basel

Roderick Y H Lim

University of Basel

Andreas Dahlin

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Andreas Dahlin Group

Nanoscale

2040-3364 (ISSN)

Vol. 10 10 4663-4669

Subject Categories

Physical Chemistry

Biophysics

Theoretical Chemistry

DOI

10.1039/c7nr09432a

More information

Latest update

1/17/2019