, Volume 5, Issue 2, pp 161–167 | Cite as

The Optimal Aspect Ratio of Gold Nanorods for Plasmonic Bio-sensing

  • Jan Becker
  • Andreas Trügler
  • Arpad Jakab
  • Ulrich Hohenester
  • Carsten Sönnichsen


The plasmon resonance of metal nanoparticles shifts upon refractive index changes of the surrounding medium through the binding of analytes. The use of this principle allows one to build ultra-small plasmon sensors that can detect analytes (e.g., biomolecules) in volumes down to attoliters. We use simulations based on the boundary element method to determine the sensitivity of gold nanorods of various aspect ratios for plasmonic sensors and find values between 3 and 4 to be optimal. Experiments on single particles confirm these theoretical results. We are able to explain the optimum by showing a corresponding maximum for the quality factor of the plasmon resonance.


Plasmon Sensors Nanorods BEM Spectroscopy Nanoparticles Nanocrystals Gold 



We acknowledge financial support by the DFG through the Emmy Noether Program (SO712/1-3), the MAINZ graduate school of excellence, and the Graz Advanced School of Science (NAWI GASS).


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Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  • Jan Becker
    • 1
  • Andreas Trügler
    • 2
  • Arpad Jakab
    • 1
  • Ulrich Hohenester
    • 2
  • Carsten Sönnichsen
    • 1
  1. 1.Institute of Physical ChemistryUniversity of MainzMainzGermany
  2. 2.Institute of PhysicsKarl-Franzens University GrazGrazAustria

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