Combined QCM-D/GE as a tool to characterize stimuli-responsive swelling of and protein adsorption on polymer brushes grafted onto 3D-nanostructures

Meike Koenig, Tadas Kasputis, Daniel Schmidt, Keith B. Rodenhausen, Klaus Jochen Eichhorn, Angela K. Pannier, Mathias Schubert, Manfred Stamm, Petra Uhlmann

Research output: Contribution to journalArticle

16 Scopus citations

Abstract

A combined setup of quartz crystal microbalance and generalized ellipsometry can be used to comprehensively investigate complex functional coatings comprising stimuli-responsive polymer brushes and 3D nanostructures in a dynamic, noninvasive in situ measurement. While the quartz crystal microbalance detects the overall change in areal mass, for instance, during a swelling or adsorption process, the generalized ellipsometry data can be evaluated in terms of a layered model to distinguish between processes occurring within the intercolumnar space or on top of the anisotropic nanocolumns. Silicon films with anisotropic nanocolumnar morphology were prepared by the glancing angle deposition technique and further functionalized by grafting of poly-(acrylic acid) or poly-(N- isopropylacrylamide) chains. Investigations of the thermoresponsive swelling of the poly-(N-isopropylacrylamide) brush on the Si nanocolumns proved the successful preparation of a stimuli-responsive coating. Furthermore, the potential of these novel coatings in the field of biotechnology was explored by investigation of the adsorption of the model protein bovine serum albumin. Adsorption, retention, and desorption triggered by a change in the pH value is observed using poly-(acrylic acid) functionalized nanostructures, although generalized ellipsometry data revealed that this process occurs only on top of the nanostructures. Poly-(N-isopropylacrylamide) is found to render the nanostructures non-fouling properties.

Original languageEnglish (US)
Pages (from-to)7233-7242
Number of pages10
JournalAnalytical and Bioanalytical Chemistry
Volume406
Issue number28
DOIs
Publication statusPublished - Nov 2014

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Keywords

  • Biomaterials
  • Interface/surface analysis
  • Nanostructures
  • Polymer brushes
  • Protein adsorption
  • Thin films

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry

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