Adsorption behavior of DNA-wrapped carbon nanotubes on self-assembled monolayer surfaces

Langmuir. 2007 May 22;23(11):6252-6. doi: 10.1021/la063109e. Epub 2007 Apr 25.

Abstract

We have examined the adsorption of DNA-wrapped single-walled carbon nanotubes (DNA-SWNTs) on hydrophobic, hydrophilic, and charged surfaces of alkylthiol self-assembled monolayers (SAMs) on gold. Our goal is to understand how DNA-SWNTs interact with surfaces of varying chemical functionality. These samples were characterized using reflection absorption FTIR (RAIRS), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. We have found that DNA-SWNTs preferentially adsorb to positively charged amine-terminated SAMs and to bare gold surfaces versus hydrophobic methyl-terminated or negatively charged carboxylic acid-terminated SAMs. Examination of the adsorption on gold of single-strand DNA (ssDNA) of the same sequence used to wrap the SWNTs suggests that the DNA wrapping plays a role in the adsorption behavior of DNA-SWNTs.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adsorption
  • DNA / chemistry*
  • Electrochemistry
  • Gold / chemistry
  • Hydrophobic and Hydrophilic Interactions
  • Nanotubes, Carbon / chemistry*
  • Spectroscopy, Fourier Transform Infrared
  • Spectrum Analysis
  • Spectrum Analysis, Raman
  • Surface Properties
  • X-Rays

Substances

  • Nanotubes, Carbon
  • Gold
  • DNA