Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2008 Dec 30;105(52):20701-4.
doi: 10.1073/pnas.0808988106. Epub 2008 Dec 15.

Single virus detection from the reactive shift of a whispering-gallery mode

F Vollmer  1 , S Arnold, D Keng
Affiliations

Single virus detection from the reactive shift of a whispering-gallery mode

F Vollmer et al. Proc Natl Acad Sci U S A. .

Abstract

We report the label-free, real-time optical detection of Influenza A virus particles. Binding of single virions is observed from discrete changes in the resonance frequency/wavelength of a whispering-gallery mode excited in a microspherical cavity. We find that the magnitude of the discrete wavelength-shift signal can be sufficiently enhanced by reducing the microsphere size. A reactive sensing mechanism with inverse dependence on mode volume is confirmed in experiments with virus-sized polystyrene nanoparticles. By comparing the electromagnetic theory for this reactive effect with experiments, the size and mass ( approximately 5.2 x 10(-16) g) of a bound virion are determined directly from the optimal resonance shift.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Fig. 1.
Fig. 1.
Excitation of an equatorial WGM of a microsphere by evanescent coupling to a guided wave in a tapered optical fiber. Resonance positions are detected as dips in the transmitted light T at particular laser wavelengths.
Fig. 2.
Fig. 2.
Nanoparticle wavelength shift. (A) Dip-trace for a = 250 nm PS particles interacting with a microsphere with R ≈ 45 mm. (B) A 15 second zoom-in. (C) Wavelength step statistics.
Fig. 3.
Fig. 3.
Maximum step height vs. microsphere curvature for polystyrene particles with radius a = 250 nm.
Fig. 4.
Fig. 4.
Shift signal for InfA. The data were acquired for a microsphere with R = 39 mm, and a DFB laser having a nominal wavelength of 763 nm.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Ewald P.W. In: The Next Fifty Years. Brockman J, editor. New York: Vintage Books; 2002. pp. 289–301.
    1. Arnold S, Khoshsima M, Teraoka I, Holler S, Vollmer F. Shift of whispering gallery modes in microspheres by protein adsorption. Opt Lett. 2003;28:272–274. - PubMed
    1. Arnold S, Ramjit R, Keng D, Kolchenko V, Teraoka I. Microparticle photophysics illuminates viral biosensing. Faraday Discuss. 2008;137:65–85. - PubMed
    1. Patolsky F, et al. Electrical detection of single viruses. PROC NATL ACAD SCI USA. 2004;101:14017–14022. - PMC - PubMed
    1. Ignatovich FV, Novotny L. Real-time and background-free detection of nanoscale particles. Phys Rev Lett. 2006;96:0139011–0139014. - PubMed

Publication types

LinkOut - more resources