scholarly journals A study of the subdiffusion of small molecules in charged polyelectrolyte multilayers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
I. Vardanyan ◽  
V. Arakelyan ◽  
Z. Navoyan ◽  
Eleftheria Diamanti ◽  
S. E. Moya ◽  
...  
Keyword(s):  
Small Molecules ◽  
Sodium Dithionite ◽  
Fluorescence Decay ◽  
Markovian Process ◽  
Polyelectrolyte Multilayers ◽  
Diffusion Equations ◽  
Polystyrene Sulfonate ◽  
Slow Diffusion ◽  
Polyallylamine Hydrochloride ◽  
Positively Charged

AbstractA theoretical approach has been developed here to describe the slow diffusion of small charged molecules of sodium dithionite (S2O42−) in polyelectrolyte multilayers (PEMs) composed of polyallylamine hydrochloride (PAH) and polystyrene sulfonate (PSS), which is demonstrated here to be a case of subdifussion. Diffusion is measured experimentally by recording the quenching of the fluorescence of (7-nitrobenz-2-oxa-1,3-diazol-4yl) amino (NBD) labelled PAH layers assembled on silica particles by flow cytometry. NBD is reduced when it encounters dithionite leading to the disappearance of the fluorescence. The fluorescence decay curves show a slow diffusion of dithionite, that does not follow classical Fickean law. Dithionite diffusion in the PEMs is shown to be a non-Markovian process and the slow diffusion can be described via diffusion equations with fractional time derivatives. Results are explained assuming subdifussion of dithionite in the PEMs, as a result of the trapping of the negatively charged dithionite in the positively charged layers of PAH.

A typical diffusion monitored by flow cytometry: slow diffusion of small molecules in polyelectrolyte multilayers

Nanoscale ◽  
2018 ◽  
Vol 10 (2) ◽  
pp. 765-772 ◽  
Author(s):  
E. Donath ◽  
I. Vardanyan ◽  
S. Meyer ◽  
R. A. Murray ◽  
S. E. Moya ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Small Molecules ◽  
Small Molecule ◽  
Colloidal Particles ◽  
Polyelectrolyte Multilayers ◽  
Innovative Approach ◽  
Slow Diffusion

An innovative approach has been developed to measure small molecule diffusion in polyelectrolyte multilayers assembled on colloidal particles by means of flow cytometry.

The effect of top-layer chemistry on the formation of supported lipid bilayers on polyelectrolyte multilayers: primary versus quaternary amines

2016 ◽  
Vol 18 (47) ◽  
pp. 32396-32405 ◽  
Author(s):  
E. Diamanti ◽  
P. Andreozzi ◽  
R. Anguiano ◽  
L. Yate ◽  
D. Gregurec ◽  
...  
Keyword(s):  
Surface Chemistry ◽  
Lipid Bilayers ◽  
Polyelectrolyte Multilayers ◽  
Supported Lipid Bilayers ◽  
Polystyrene Sulfonate

The influence of the surface chemistry of PEMs on the formation of lipid bilayers is studied here for PEMs with different cationic amines as a top layer, and polystyrene sulfonate (PSS) as a polyanion.

scholarly journals Application of the Active Space Self-Interaction-Correction Method to Molecular Systems

2017 ◽  
Vol 56 (3) ◽  
Author(s):  
Felipe Aparicio ◽  
Jorge Garza ◽  
Marcelo Galván
Keyword(s):  
Small Molecules ◽  
Correction Method ◽  
Chem Phys ◽  
Computational Effort ◽  
Eigenvalue Spectrum ◽  
Remarkable Change ◽  
Molecular Systems ◽  
Active Space ◽  
Regional Character ◽  
Positively Charged

Within the context of the active space of the self-interactioncorrection (SIC) optimized effective potential (OEP) method (<em>J. Chem. Phys.</em> <strong>2001</strong>, <em>114</em>, 639-651), the effect of the inclusion of the SIC at the level of only use the HOMO orbital is analyzed for a set of small molecules and for a model of an interstitial region surrounded by positively charged groups in a polypeptide; the model is representative of a class of regions occurring in proteins. It is shown, for the molecular systems treated in this work, that the inclusion of the HOMO orbital, within the SIC-OEP, induces a remarkable change on the eigenvalue spectrum. For the interstitial state model, the improvement is systematic as one increase the active space from one to ten orbitals; also, the influence on the local behavior of the interstitial virtual state closest to the Fermi level is important and enhances its regional character. As this method reduces the computational effort to introduce the SIC it seems promising to deal with self-interaction-corrections in systems with many atoms/electrons such as biomolecules

scholarly journals Polyelectrolyte-Stabilised Magnetic-Plasmonic Nanocomposites

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1044
Author(s):  
Shelley Stafford ◽  
Coralie Garnier ◽  
Yurii Gun’ko
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nanocomposite Materials ◽  
Biological Applications ◽  
Polystyrene Sulfonate ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Allylamine Hydrochloride ◽  
Plasmonic Nanocomposite ◽  
Positively Charged

In this work, new magnetic-plasmonic nanocomposites have been developed through the use of two complementary polyelectrolytes–polystyrene sulfonate (PSS) and poly(allylamine hydrochloride) (PAH). PSS, a negatively charged polyelectrolyte, was utilized as a stabiliser for magnetite nanoparticles, and PAH, a positively charged polyelectrolyte, was used to stabilize gold nanoparticles. The combination of these two entities resulted in a magnetic-plasmonic nanocomposite that is highly reproducible and scalable. This approach was found to work for a variety of PSS concentrations. The produced magnetic-plasmonic nanomaterials have been characterized by vibrational sample magnetometry (VSM), transmission electron microscopy (TEM) and UV-Vis spectroscopy. These nanocomposite materials have the potential to be used in a variety of biological applications including bioseparation and biosensing.

Protein Interactions with Polyelectrolyte Multilayers:  Interactions between Human Serum Albumin and Polystyrene Sulfonate/Polyallylamine Multilayers

2000 ◽  
Vol 1 (4) ◽  
pp. 674-687 ◽  
Author(s):  
Guy Ladam ◽  
Csilla Gergely ◽  
Bernard Senger ◽  
Gero Decher ◽  
Jean-Claude Voegel ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Protein Interactions ◽  
Polyelectrolyte Multilayers ◽  
Polystyrene Sulfonate
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