Adsorption Kinetics in Open Nanopores as a Source of Low-Frequency Noise.

Nano Lett

Laboratoire de Physique de l'Ecole Normale Supérieure , CNRS, Université PSL, Sorbonne Université, Sorbonne Paris Cité , Paris 75005 , France.

Published: October 2019

Ionic current measurements through solid-state nanopores consistently show a power spectral density that scales as 1/  at low frequency , with an exponent α ∼ 0.5-1.5, but strikingly, the physical origin of this behavior remains elusive. Here, we perform simulations of particles reversibly adsorbing at the surface of a nanopore and show that the fluctuations in the number of adsorbed particles exhibit low-frequency pink noise. We furthermore propose theoretical modeling for the time-dependent adsorption of particles on the nanopore surface for various geometries, which predicts a frequency spectrum in very good agreement with the simulation results. Altogether, our results highlight that the low-frequency noise takes its origin in the reversible adsorption of ions at the pore surface combined with the long-lasting excursions of the ions in the reservoirs. The scaling regime of the power spectrum extends down to a cutoff frequency which is far smaller than simple diffusion estimates. Using realistic values for the pore dimensions and the adsorption-desorption kinetics, this predicts the observation of pink noise for frequencies down to the hertz for a typical solid-state nanopore, in good agreement with experiments.

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.nanolett.9b02858DOI Listing

Publication Analysis

Top Keywords

low-frequency noise
8
pink noise
8
good agreement
8
adsorption kinetics
4
kinetics open
4
open nanopores
4
nanopores source
4
source low-frequency
4
noise
4
noise ionic
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!