Microcavity single virus detection and sizing with molecular sensitivity

V. R. Dantham, S. Holler, V. Kolchenko, Z. Wan, S. Arnold

Research output: Chapter in Book/Report/Conference proceedingConference contribution


We report the label-free detection and sizing of the smallest individual RNA virus, MS2 by a spherical microcavity. Mass of this virus is ∼6 ag and produces a theoretical resonance shift ∼0.25 fm upon adsorbing an individual virus at the equator of the bare microcavity, which is well below the r.m.s background noise of 2 fm. However, detection was accomplished with ease (S/N = 8, Q = 4x105) using a single dipole stimulated plasmonic-nanoshell as a microcavity wavelength shift enhancer. Analytical expressions based on the "reactive sensing principle" are developed to extract the radius of the virus from the measured signals. Estimated limit of detection for these experiments was ∼0.4 ag or 240 kDa below the size of all known viruses, largest globular and elongated proteins [Phosphofructokinase (345 kDa) and Fibrinogen (390 kDa), respectively].

Original languageEnglish (US)
Title of host publicationLaser Resonators, Microresonators, and Beam Control XV
StatePublished - 2013
EventLaser Resonators, Microresonators, and Beam Control XV - San Francisco, CA, United States
Duration: Feb 3 2013Feb 7 2013

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherLaser Resonators, Microresonators, and Beam Control XV
Country/TerritoryUnited States
CitySan Francisco, CA


  • Whispering gallery mode
  • biosensor
  • localized surface plasmon resonance
  • microcavity
  • virus detection

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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