7711
2014
eng
1847
1858
12
17
3
article
The Royal Society of Chemistry
Cambridge
1
--
2014-11-26
--
Non-universal tracer diffusion in crowded media of non-inert obstacles
We study the diffusion of a tracer particle, which moves in continuum space between a lattice of excluded volume, immobile non-inert obstacles. In particular, we analyse how the strength of the tracer–obstacle interactions and the volume occupancy of the crowders alter the diffusive motion of the tracer. From the details of partitioning of the tracer diffusion modes between trapping states when bound to obstacles and bulk diffusion, we examine the degree of localisation of the tracer in the lattice of crowders. We study the properties of the tracer diffusion in terms of the ensemble and time averaged mean squared displacements, the trapping time distributions, the amplitude variation of the time averaged mean squared displacements, and the non-Gaussianity parameter of the diffusing tracer. We conclude that tracer–obstacle adsorption and binding triggers a transient anomalous diffusion. From a very narrow spread of recorded individual time averaged trajectories we exclude continuous type random walk processes as the underlying physical model of the tracer diffusion in our system. For moderate tracer–crowder attraction the motion is found to be fully ergodic, while at stronger attraction strength a transient disparity between ensemble and time averaged mean squared displacements occurs. We also put our results into perspective with findings from experimental single-particle tracking and simulations of the diffusion of tagged tracers in dense crowded suspensions. Our results have implications for the diffusion, transport, and spreading of chemical components in highly crowded environments inside living cells and other structured liquids.
Physical Chemistry Chemical Physics
1463-9076
online registration
Au-006431
<a href="http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-77128">Zweitveröffentlichung in der Schriftenreihe Postprints der Universität Potsdam : Humanwissenschaftliche Reihe ; 186</a>
Surya K. Ghosh
Andrey G. Cherstvy
Ralf Metzler
eng
uncontrolled
fluorescence correlation spectroscopy
eng
uncontrolled
single-particle tracking
eng
uncontrolled
anomalous diffusion
eng
uncontrolled
living cells
eng
uncontrolled
physiological consequences
eng
uncontrolled
langevin equation
eng
uncontrolled
infection pathway
eng
uncontrolled
excluded volume
eng
uncontrolled
brownian-motion
eng
uncontrolled
random-walks
Chemie und zugeordnete Wissenschaften
Institut für Chemie
Referiert
Open Access
RSC
7712
2014
2014
eng
1847
1858
12
postprint
The Royal Society of Chemistry
Cambridge
1
2015-05-22
2014-11-26
--
Non-universal tracer diffusion in crowded media of non-inert obstacles
We study the diffusion of a tracer particle, which moves in continuum space between a lattice of excluded volume, immobile non-inert obstacles. In particular, we analyse how the strength of the tracer–obstacle interactions and the volume occupancy of the crowders alter the diffusive motion of the tracer. From the details of partitioning of the tracer diffusion modes between trapping states when bound to obstacles and bulk diffusion, we examine the degree of localisation of the tracer in the lattice of crowders. We study the properties of the tracer diffusion in terms of the ensemble and time averaged mean squared displacements, the trapping time distributions, the amplitude variation of the time averaged mean squared displacements, and the non-Gaussianity parameter of the diffusing tracer. We conclude that tracer–obstacle adsorption and binding triggers a transient anomalous diffusion. From a very narrow spread of recorded individual time averaged trajectories we exclude continuous type random walk processes as the underlying physical model of the tracer diffusion in our system. For moderate tracer–crowder attraction the motion is found to be fully ergodic, while at stronger attraction strength a transient disparity between ensemble and time averaged mean squared displacements occurs. We also put our results into perspective with findings from experimental single-particle tracking and simulations of the diffusion of tagged tracers in dense crowded suspensions. Our results have implications for the diffusion, transport, and spreading of chemical components in highly crowded environments inside living cells and other structured liquids.
urn:nbn:de:kobv:517-opus4-77128
online registration
Au-006431
Phys. Chem. Chem. Phys., 2015,17, 1847-1858. - DOI: 10.1039/C4CP03599B
<a href="http://publishup.uni-potsdam.de/opus4-ubp/frontdoor/index/index/docId/7711">Bibliographieeintrag der Originalveröffentlichung/Quelle</a>
Surya K. Ghosh
Andrey G. Cherstvy
Ralf Metzler
Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
186
eng
uncontrolled
escence correlation spectroscopy
eng
uncontrolled
single-particle tracking
eng
uncontrolled
anomalous diffusion
eng
uncontrolled
living cells
eng
uncontrolled
physiological consequences
eng
uncontrolled
langevin equation
eng
uncontrolled
infection pathway
eng
uncontrolled
excluded volume
eng
uncontrolled
brownian-motion
eng
uncontrolled
random-walks
Chemie und zugeordnete Wissenschaften
open_access
Institut für Chemie
Referiert
Open Access
https://publishup.uni-potsdam.de/opus4-ubp/files/7712/pmnr186.pdf