title: Alignment of SWNTs by protein-ligand interaction of functionalized magnetic particles under low magnetic fields.
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.
authors.affiliation: BioProcess Engineering Research Center, Institute for the BioCentury, KAIST 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Korea.
authors.forename: Tae Jung
authors.initials: TJ
authors.lastname: Park
authors.forename: Jong Pil
authors.initials: JP
authors.lastname: Park
authors.forename: Seok Jae
authors.initials: SJ
authors.lastname: Lee
authors.forename: Dae-Hwan
authors.initials: DH
authors.lastname: Jung
authors.forename: Young Koan
authors.initials: YK
authors.lastname: Ko
authors.forename: Hee-Tae
authors.initials: HT
authors.lastname: Jung
authors.forename: Sang Yup
authors.initials: SY
authors.lastname: Lee
mesh_terms: D008024:Ligands; D008280:Magnetics; D008855:Microscopy, Electron, Scanning; D037742:Nanotubes, Carbon; D011485:Protein Binding; D011506:Proteins / Q000378:metabolism*
chemical_list: D008024:Ligands; D037742:Nanotubes, Carbon; D011506:Proteins