Near-field optical and shear-force microscopy of single fluorophores and DNA molecules

M.F. Garcia Parajo, J.A. Veerman, A.G.T. Ruiter, N.F. van Hulst

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Abstract

Photodynamics of individual fluorescence molecules has been studied using an aperture-type near-field scanning optical microscope with two channel fluorescence polarisation detection and tuning fork shear-force feedback. The position of maximum fluorescence from individual molecules could be localised with an accuracy of 1 nm. Dynamic processes such as translational and rotational diffusion were observed for molecules adsorbed to a glass surface or embedded in a polymer host. The in-plane molecular dipole orientation could be determined by monitoring the relative contribution of the fluorescence signal in the two perpendicular polarised direct:ions. Rotational dynamics was investigated o­n 10 ms-1000 s timescale. Shear-force phase feedback was used to obtain topographic imaging of DNA fragments, with a lateral and vertical resolution comparable to scanning force microscopy. A DNA height of 1.4 nm has been measured, an indication of the non-disturbing character of the shear force mechanism.
Original languageUndefined
Pages (from-to)311-319
Number of pages9
JournalUltramicroscopy
Volume1998
Issue number71
DOIs
Publication statusPublished - 1998

Keywords

  • Dynamics
  • Photodynamics
  • Optical microscopy
  • Molecules
  • Fluorescence
  • METIS-128615
  • DNA
  • Diffusion
  • Shear force microscopy
  • IR-23816
  • Fluorophores

Cite this

Garcia Parajo, M. F., Veerman, J. A., Ruiter, A. G. T., & van Hulst, N. F. (1998). Near-field optical and shear-force microscopy of single fluorophores and DNA molecules. Ultramicroscopy, 1998(71), 311-319. https://doi.org/10.1016/S0304-3991(97)00086-7