Details

Autor(en) / Beteiligte

• Emilsson, Gustav
• Xiong, Kunli
• Sakiyama, Yusuke
• Malekian, Bita
• Ahlberg Gagnér, Viktor
• Schoch, Rafael L
• Lim, Roderick Y H
• Dahlin, Andreas B

Titel

Polymer brushes in solid-state nanopores form an impenetrable entropic barrier for proteins

Ist Teil von

• Nanoscale, 2018, Vol.10 (10), p.4663-4669

Ort / Verlag

England: Royal Society of Chemistry

Erscheinungsjahr

2018

Quelle

MEDLINE

Beschreibungen/Notizen

• 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.