AVS 52nd International Symposium
    DNA Topical Conference Monday Sessions
       Session DN+BI-MoM

Paper DN+BI-MoM5
Adsorption of DNA-wrapped Carbon Nanotubes on SAM Modified Gold Surfaces

Monday, October 31, 2005, 9:40 am, Room 311

Session: DNA Structures and Surfaces
Presenter: R.A. Zangmeister, NIST
Authors: R.A. Zangmeister, NIST
A.M. Opdahl, NIST
M.J. Tarlov, NIST
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We are studying the structure of DNA-wrapped carbon nanotubes (CNTs) on gold surfaces modified with alkanethiol self-assembled monolayers (SAMs). Our goal is to understand how DNA-wrapped CNTs interact with surfaces of varying chemical functionality and to use this knowledge to develop general strategies for controlling the assembly and alignment of DNA-wrapped CNTs on surfaces. Recently, Zheng and coworkers found that single-stranded DNA wraps around CNTs, improving their solubility in aqueous solutions and enabling their separation according to diameter and electronic properties.@footnote 1@ We postulate that the well-defined nature of the DNA-conjugated CNTs will allow their precise assembly and alignment on surfaces. We have examined the adsorption of DNA-wrapped CNTs on hydrophobic, hydrophilic, charged, and spatially patterned alkanethiol SAMs on gold. These samples are characterized using reflection absorption FTIR, scanning electron microscopy, and scanning probe microscopy. We have found that DNA-wrapped CNTs preferentially adsorb to positively charged amine terminated SAMs and to bare gold surfaces versus hydrophobic methyl terminated or negatively charged carboxylic acid terminated SAMs, indicating that electrostatic interactions play a major role in the deposition of these materials. In addition, general strategies for controlling the density and alignment of DNA-wrapped CNTs using alkanethiol SAMs will be discussed. @FootnoteText@ @footnote 1@Zheng, M., et al. Nature Materials 2003, 2, 338-342.