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Title: Single-molecule analysis of ultradilute solutions with guided streams of 1-{mu}m water droplets

Journal Article · · Applied Optics
; ; ; ;  [1]
  1. Oak Ridge National Laboratory,, P. O. Box 2008, Oak Ridge, Tennessee 37831-6142 (United States)

We describe instrumentation for real-time detection of single-molecule fluorescence in guided streams of 1-{mu}m (nominal) water droplets. In this technique, target molecules were confined to droplets whose volumes were comparable with illumination volumes in diffraction-limited fluorescence microscopy and guided to the waist of a cw probe laser with an electrostatic potential. Concentration detection limits for Rhodamine 6G in water were determined to be {approximately}1 fM, roughly 3 orders of magnitude lower than corresponding limits determined recently with diffraction-limited microscopy techniques for a chemical separation of similar dyes. In addition to its utility as a vehicle for probing single molecules, instrumentation for producing and focusing stable streams of 1{endash}2-{mu}m-diameter droplets may have other important analytical applications as well. {copyright} 1999 Optical Society of America

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
DOE Contract Number:
AC05-96OR22464
OSTI ID:
338654
Journal Information:
Applied Optics, Vol. 38, Issue 9; Other Information: PBD: Mar 1999
Country of Publication:
United States
Language:
English