Unexpected ionic transport behavior in hydrophobic and uncharged conical nanopores.

Date publication

octobre 2018

Journal

Faraday discussions

Auteurs

Membres identifiés du Cancéropôle Est :
Dr PICAUD Fabien

Tous les auteurs :
Balme S, Picaud F, Lepoitevin M, Bechelany M, Balanzat E, Janot JM

Lien Pubmed

https://www.ncbi.nlm.nih.gov/pubmed/29992218

Résumé

We investigated ionic transport behavior in the case of uncharged conical nanopores. To do so, we designed conical nanopores using atomic layer deposition of Al2O3/ZnO nanolaminates and then coated these with trimethylsilane. The experimental results are supported by molecular dynamics simulations. The ionic transport reveals an unexpected behavior: (i) a current rectification and (ii) a constant conductance at low salt concentration which are usually reported for charged conical nanopore. To explain these results, we have considered different assumptions: (i) a default of functionalization, (ii) the adsorption anion and (iii) the slippage. The first one was refuted by the study of the poly-l-lysine transport through the nanopore. To verify the second assumption, we investigate the effect of pH on the current rectification and the molecular dynamics simulations. Finally our study demonstrates that the unexpected ionic transport is provided to a predominant effect of slippage due to the water organization at the solid/liquid interface.

Référence

Faraday Discuss. 2018 10 1;210:69-85