Format

Send to

Choose Destination
Science. 2007 Aug 10;317(5839):783-7. Epub 2007 Jul 5.

Label-free, single-molecule detection with optical microcavities.

Author information

1
Department of Applied Physics, MC 128-95, California Institute of Technology, Pasadena, CA 91125, USA.

Erratum in

  • Science. 2011 Dec 16;334(6062):1496.

Abstract

Current single-molecule detection techniques require labeling the target molecule. We report a highly specific and sensitive optical sensor based on an ultrahigh quality (Q) factor (Q > 10(8)) whispering-gallery microcavity. The silica surface is functionalized to bind the target molecule; binding is detected by a resonant wavelength shift. Single-molecule detection is confirmed by observation of single-molecule binding events that shift the resonant frequency, as well as by the statistics for these shifts over many binding events. These shifts result from a thermo-optic mechanism. Additionally, label-free, single-molecule detection of interleukin-2 was demonstrated in serum. These experiments demonstrate a dynamic range of 10(12) in concentration, establishing the microcavity as a sensitive and versatile detector.

PMID:
17615303
DOI:
10.1126/science.1145002
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center