Alignment of SWNTs by protein-ligand interaction of functionalized magnetic particles under low magnetic fields

J Nanosci Nanotechnol. 2011 May;11(5):4540-5. doi: 10.1166/jnn.2011.3668.

Abstract

Carbon nanotubes (CNTs) have attracted considerable attention for applications using their superior mechanical, thermal and electrical properties. A simple method to controllably align single-walled CNTs (SWNTs) by using magnetic particles embedded with superparamagnetic iron oxide as an accelerator under the magnetic field was developed. The functionalization of SWNTs using biotin, interacted with streptavidin-coupled magnetic particles (micro-to-nano in diameter), and layer-by-layer assembly were performed for the alignment of a particular direction onto the clean silicon and the gold substrate at very low magnetic forces (0.02-0.89 T) at room temperature. The successful alignment of the SWNTs with multi-layer film was observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). By changing the orientation and location of the substrates, crossed-networks of SWNTs-magnetic particle complex could easily be fabricated. We suggest that this approach, which consists of a combination of biological interaction among streptavidin-biotin and magnetite particles, should be useful for lateral orientation of individual SWNTs with controllable direction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ligands
  • Magnetics*
  • Microscopy, Electron, Scanning
  • Nanotubes, Carbon*
  • Protein Binding
  • Proteins / metabolism*

Substances

  • Ligands
  • Nanotubes, Carbon
  • Proteins