Confining the sampling volume for Fluorescence Correlation Spectroscopy using a sub-wavelength sized aperture

For the observation of single molecule dynamics with fluorescence fluctuation spectroscopy (FFS) very low fluorophore concentrations are necessary. For in vitro measurements, this requirement is easy to fulfill. In biology however, micromolar concentrations are often encountered and may pose a real challenge to conventional FFS methods based on confocal instrumentation. We show a higher confinement of the sampling volume in the near-field of sub-wavelength sized apertures in a thin gold film. The gold apertures have been measured and characterized with fluorescence correlation spectroscopy (FCS), indicating light confinement beyond the far-field diffraction limit. We measured a reduction of the effective sampling volume by an order of magnitude compared to confocal instrumentation. (c) 2006 Optical Society of America.


Published in:
Optics Express, 14, 956-969
Presented at:
OSA Topical Meeting on Signal Recovery and Synthesis, Charlotte, NC, Jun, 2005
Year:
2006
Publisher:
Optical Society of America
ISSN:
1094-4087
Keywords:
Laboratories:




 Record created 2011-04-11, last modified 2018-03-17

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