skip to main content

SciTech ConnectSciTech Connect

Title: Entropically induced asymmetric passage times of charged tracers across corrugated channels

We analyze the diffusion of charged and neutral tracers suspended in an electrolyte embedded in a channel of varying cross section. Making use of systematic approximations, the diffusion equation governing the motion of tracers is mapped into an effective 1D equation describing the dynamics along the longitudinal axis of the channel where its varying-section is encoded as an effective entropic potential. This simplified approach allows us to characterize tracer diffusion under generic confinement by measuring their mean first passage time (MFPT). In particular, we show that the interplay between geometrical confinement and electrostatic interactions strongly affect the MFTP of tracers across corrugated channels hence leading to alternative means to control tracers translocation across charged pores. Finally, our results show that the MFPTs of a charged tracer in opposite directions along an asymmetric channel may differ We expect our results to be relevant for biological as well synthetic devices whose dynamics is controlled by the detection of diluted tracers.
Authors:
 [1] ;  [2] ;  [3] ; ;  [4]
  1. Max-Planck-Institut für Intelligente Systeme, Heisenbergstr. 3, D-70569 Stuttgart (Germany)
  2. (Germany)
  3. (Spain)
  4. Department de Fisica Fonamental, Universitat de Barcelona, Barcelona (Spain)
Publication Date:
OSTI Identifier:
22493673
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 144; Journal Issue: 3; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ASYMMETRY; CONFINEMENT; CROSS SECTIONS; DETECTION; DIFFUSION; DIFFUSION EQUATIONS; ELECTROLYTES; POTENTIALS; TRANSLOCATION