Biointerphases

Journal for Biophysical Chemistry

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Open Access

Protein resistant oligo(ethylene glycol) terminated self-assembled monolayers of thiols on gold by vapor deposition in vacuum

  • Laxman Kankate1,
  • Udo Werner1,
  • Andrey Turchanin1,
  • Armin Gölzhäuser1,
  • Helge Großmann2 and
  • Robert Tampé2
Biointerphases5:50200030

https://doi.org/10.1116/1.3407483

Received: 19 February 2010

Accepted: 1 April 2010

Abstract

Protein resistant oligo(ethylene glycol) (OEG) terminated self-assembled monolayers SAMs) of thiols on gold are commonly used for suppression of nonspecific protein adsorption in biology and biotechnology. The standard preparation for these SAMs is the solution method (SM) that involves immersion of the gold surface in an OEG solution. Here the authors present the preparation of 11-(mercaptoundecyl)-triethylene glycol [HS(CH2)11(OCH2CH2)3OH] SAMs on gold surface by vapor deposition (VD) in vacuum. They compare the properties of SAMs prepared by VD and SM using x-ray photoelectron spectroscopy (XPS), polarization modulation infrared reflection absorption spectroscopy, and surface plasmon resonance measurements. VD and SM SAMs exhibit similar packing density and show a similar resistance to the nonspecific adsorption of various proteins bovine serum albumin, trypsin, and myoglobin) under physiological conditions. A very high sensitivity of the OEG SAMs to x-ray radiation is found, which allows tuning their protein resistance. These results show a new path to in situ engineering, analysis, and patterning of protein resistant OEG SAMs by high vacuum and ultrahigh vacuum techniques.