Polymer brushes in solid-state nanopores form an impenetrable entropic barrier for proteins
Artikel i vetenskaplig tidskrift, 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.

Författare

Gustav Emilsson

Kemi och kemiteknik, Tillämpad kemi, Teknisk ytkemi

Kunli Xiong

Andreas Dahlin Group

Yusuke Sakiyama

Universität Basel

Bita Malekian

Andreas Dahlin Group

Viktor Ahlberg Gagnér

Chalmers, Kemi och kemiteknik

Rafael L. Schoch

Universität Basel

Roderick Y H Lim

Universität Basel

Andreas Dahlin

Andreas Dahlin Group

Nanoscale

2040-3364 (ISSN)

Vol. 10 4663-4669

Ämneskategorier

Fysikalisk kemi

Biofysik

Teoretisk kemi

DOI

10.1039/c7nr09432a