Structural and functional imaging with carbon nanotube AFM probes

J. H. Hafner, C. L. Cheung, A. T. Woolley, C. M. Lieber

Research output: Contribution to journalReview article

284 Scopus citations

Abstract

Atomic force microscopy (AFM) has great potential as a tool for structural biology, a field in which there is increasing demand to characterize larger and more complex biomolecular systems. However, the poorly characterized silicon and silicon nitride probe tips currently employed in AFM limit its biological applications. Carbon nanotubes represent ideal AFM tip materials due to their small diameter, high aspect ratio, large Young's modulus, mechanical robustness, well-defined structure, and unique chemical properties. Nanotube probes were first fabricated by manual assembly, but more recent methods based on chemical vapor deposition provide higher resolution probes and are geared towards mass production, including recent developments that enable quantitative preparation of individual single-walled carbon nanotube tips [J. Phys. Chem. B 105 (2001) 743]. The high-resolution imaging capabilities of these nanotube AFM probes have been demonstrated on gold nanoparticles and well-characterized biomolecules such as IgG and GroES. Using the nanotube probes, new biological structures have been investigated in the areas of amyloid-beta protein aggregation and chromatin remodeling, and new biotechnologies have been developed such as AFM-based haplotyping. In addition to measuring topography, chemically functionalized AFM probes can measure the spatial arrangement of chemical functional groups in a sample. However, standard silicon and silicon nitride tips, once functionalized, do not yield sufficient resolution to allow combined structural and functional imaging of biomolecules. The unique end-group chemistry of carbon nanotubes, which can be arbitrarily modified by established chemical methods, has been exploited for chemical force microscopy, allowing single-molecule measurements with well-defined functionalized tips.

Original languageEnglish (US)
Pages (from-to)73-110
Number of pages38
JournalProgress in Biophysics and Molecular Biology
Volume77
Issue number1
DOIs
Publication statusPublished - Aug 15 2001

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Keywords

  • Atomic force microscopy
  • Carbon nanotube
  • Chemical force microscopy
  • Single molecule spectroscopy
  • Structural biology

ASJC Scopus subject areas

  • Biophysics
  • Molecular Biology

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