Single Molecules and Single Gold Nanoparticles as Optical Windows on the Nanoscale

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Event details

Date 20.04.2017
Hour 16:3017:30
Speaker Prof. M.A.G.J Orrit
Leiden University
Netherlands
Location
Category Conferences - Seminars

The optical detection and study of single molecules and other nano-objects provide unique insights into the dynamics of nano-objects and their surroundings [1]. They also relate to several branches of physics, as I shall illustrate with some recent experiments.
i) The lifetime-limited lines of single molecules at cryogenic conditions probe acoustic [2] and electric perturbations, making them attractive for quantum optomechanics.
ii) We recently studied the dynamics of vapor nanobubbles created in the liquid surrounding a single immobilized gold nanosphere. These nanobubbles form in an instable, explosive process before collapsing and can react to sound waves [3].
iii) Photothermal microscopy opens the study of non-fluorescent absorbers, down to single-molecule sensitivity [4]. The high signal-to-noise ratio enables local plasmonic and chemical probing [5] (see Fig. 1). Fluorescence enhancements in excess of thousand-fold can be observed in a gold nanorod near field at resonance.
iv) The intense near-field at the tip of plasmonic nanorods enhances excitation and emission of single molecules diffusing in the area. Enhanced fluorescence opens single-molecule spectroscopy of dyes with very low fluorescence yields [6].

References:
[1] F. Kulzer et al., Angew. Chem. Int. Ed. 49 (2010) 854.
[2] Y. Tian et al. Phys. Rev. Lett. 113 (2014) 135505.
[3] L. Hou et al., New J. Phys. 17 (2015) 013050
[4] A. Gaiduk et al. Science 330 (2010) 353
[5] P. Zijlstra et al., Nature Nanotech. 7 (2012) 379.
[6] S. Khatua et al., ACS Nano 8 (2014) 4440.

 

Practical information

  • General public
  • Free
  • This event is internal

Contact

  • Annick Gaudin Delmonaco

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PCseminar

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