Interaction of Proteins with a Planar Poly(acrylic acid) Brush: Analysis by Quartz Crystal Microbalance with Dissipation Monitoring (QCM-D)

Jacek Walkowiak, Michael Gradzielski, Stefan Zauscher*, Matthias Ballauff*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

5 Citations (Web of Science)

Abstract

We describe the preparation of a poly(acrylic acid) (PAA) brush, polymerized by atom transfer radical polymerization (ATRP) of tert-butyl acrylate (tBA) and subsequent acid hydrolysis, on the flat gold surfaces of quartz-crystal microbalance (QCM) crystals. The PAA brushes were characterized by Fourier transform infrared (FT-IR) spectroscopy, ellipsometry and water contact angle analysis. The interaction of the PAA brushes with human serum albumin (HSA) was studied for a range of ionic strengths and pH conditions by quartz-crystal microbalance with dissipation monitoring (QCM-D). The quantitative analysis showed a strong adsorption of protein molecules onto the PAA brush. By increasing the ionic strength, we were able to release a fraction of the initially bound HSA molecules. This finding highlights the importance of counterions in the polyelectrolyte-mediated protein adsorption/desorption. A comparison with recent calorimetric studies related to the binding of HSA to polyelectrolytes allowed us to fully analyze the QCM data based on the results of the thermodynamic analysis of the binding process.

Original languageEnglish
Article number122
Number of pages15
JournalPolymers
Volume13
Issue number1
DOIs
Publication statusPublished - Jan 2021

Keywords

  • polyelectrolyte brush
  • protein
  • ATRP
  • QCM-D
  • SPHERICAL POLYELECTROLYTE BRUSHES
  • TRANSFER RADICAL POLYMERIZATION
  • BLOCK-COPOLYMERS
  • VISCOELASTIC PROPERTIES
  • SERUM-ALBUMIN
  • ADSORPTION
  • POLYMERS
  • SURFACES
  • BEHAVIOR
  • ROUTE

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