Two-photon 3D FIONA of individual quantum dots in an aqueous environment

Nano Lett. 2011 Oct 12;11(10):4074-8. doi: 10.1021/nl201225r. Epub 2011 Sep 13.


We report the first two-photon (2P) microscopy of individual quantum dots (QDs) in an aqueous environment with both widefield and point-scan excitations at nanometer accuracy. Thiol-containing reductants suppress QD blinking and enable measurement of the 36 nm step size of individual Myosin V motors in vitro. We localize QDs with an accuracy of 2-3 nm in all three dimensions by using a 9 × 9 matrix excitation hologram and an array detector, which also increases the 3D scan imaging rate by 80-fold. With this 3D microscopy we validate the LamB receptor distribution on E. coli and the endocytosis of EGF-receptors in breast cancer cells.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Validation Study

MeSH terms

  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology
  • Endocytosis
  • ErbB Receptors / metabolism
  • Female
  • Humans
  • Photons
  • Quantum Dots*
  • Water*


  • Water
  • ErbB Receptors