Molecular sorting by stochastic resonance
- *École Normale Supérieure, Département de Chimie, Centre National de la Recherche Scientifique Unité Mixte de Recherche 8640, 24 Rue Lhomond, 75231 Paris Cedex 05, France; †École Normale Supérieure, Département de Physique, Centre National de la Recherche Scientifique Unité Mixte de Recherche 8550, 24 Rue Lhomond, 75231 Paris Cedex 05, France; and §Université Pierre et Marie Curie, Laboratoire de Physique Théorique des Liquides, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7600, 4 Place Jussieu, 75252 Paris Cedex 05, France
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Edited by Harry L. Swinney, University of Texas, Austin, TX (received for review January 29, 2004)
Abstract
To sort a targeted species from a mixture, we introduce a procedure that relies on the enhancement of its effective diffusion coefficient. We use the formation of a host–guest complex between α-cyclodextrin and a dye to evidence the dye dispersion when the medium is submitted to an oscillating field. In particular, we demonstrate that the effective diffusion coefficient of the dye may be increased far beyond its intrinsic value by tuning the driving field frequency in the stochastic resonance regime. We use this effect to selectively sort from a mixture a dye that is addressed by its rate constants for association with α-cyclodextrin.
Footnotes
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↵ ‡ To whom correspondence should be addressed. E-mail: ludovic.jullien{at}ens.fr.
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This paper was submitted directly (Track II) to the PNAS office.
- Copyright © 2004, The National Academy of Sciences
