Theoretical models for electrochemical impedance spectroscopy and local ζ-potential of unfolded proteins in nanopores

Michael J. Vitarelli, David Talaga

Research output: Contribution to journalArticleResearchpeer-review

1 Citation (Scopus)

Abstract

Single solid-state nanopores find increasing use for electrical detection and/or manipulation of macromolecules. These applications exploit the changes in signals due to the geometry and electrical properties of the molecular species found within the nanopore. The sensitivity and resolution of such measurements are also influenced by the geometric and electrical properties of the nanopore. This paper continues the development of an analytical theory to predict the electrochemical impedance spectra of nanopores by including the influence of the presence of an unfolded protein using the variable topology finite Warburg impedance model previously published by the authors. The local excluded volume of, and charges present on, the segment of protein sampled by the nanopore are shown to influence the shape and peak frequency of the electrochemical impedance spectrum. An analytical theory is used to relate the capacitive response of the electrical double layer at the surface of the protein to both the charge density at the protein surface and the more commonly measured zeta potential. Illustrative examples show how the theory predicts that the varying sequential regions of surface charge density and excluded volume dictated by the protein primary structure may allow for an impedance-based approach to identifying unfolded proteins.

Original languageEnglish
Article number105101
JournalJournal of Chemical Physics
Volume139
Issue number10
DOIs
StatePublished - 14 Sep 2013

Fingerprint

Nanopores
Electrochemical impedance spectroscopy
impedance
proteins
spectroscopy
Proteins
Charge density
Membrane Proteins
Electric properties
electrical properties
Zeta potential
Surface charge
Macromolecules
macromolecules
Topology
manipulators
topology
Geometry
solid state
sensitivity

Cite this

@article{34849aef5ac34a57aac1fa75da50e5cf,
title = "Theoretical models for electrochemical impedance spectroscopy and local ζ-potential of unfolded proteins in nanopores",
abstract = "Single solid-state nanopores find increasing use for electrical detection and/or manipulation of macromolecules. These applications exploit the changes in signals due to the geometry and electrical properties of the molecular species found within the nanopore. The sensitivity and resolution of such measurements are also influenced by the geometric and electrical properties of the nanopore. This paper continues the development of an analytical theory to predict the electrochemical impedance spectra of nanopores by including the influence of the presence of an unfolded protein using the variable topology finite Warburg impedance model previously published by the authors. The local excluded volume of, and charges present on, the segment of protein sampled by the nanopore are shown to influence the shape and peak frequency of the electrochemical impedance spectrum. An analytical theory is used to relate the capacitive response of the electrical double layer at the surface of the protein to both the charge density at the protein surface and the more commonly measured zeta potential. Illustrative examples show how the theory predicts that the varying sequential regions of surface charge density and excluded volume dictated by the protein primary structure may allow for an impedance-based approach to identifying unfolded proteins.",
author = "Vitarelli, {Michael J.} and David Talaga",
year = "2013",
month = "9",
day = "14",
doi = "10.1063/1.4819470",
language = "English",
volume = "139",
journal = "Journal of Chemical Physics",
issn = "0021-9606",
publisher = "American Institute of Physics",
number = "10",

}

Theoretical models for electrochemical impedance spectroscopy and local ζ-potential of unfolded proteins in nanopores. / Vitarelli, Michael J.; Talaga, David.

In: Journal of Chemical Physics, Vol. 139, No. 10, 105101, 14.09.2013.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Theoretical models for electrochemical impedance spectroscopy and local ζ-potential of unfolded proteins in nanopores

AU - Vitarelli, Michael J.

AU - Talaga, David

PY - 2013/9/14

Y1 - 2013/9/14

N2 - Single solid-state nanopores find increasing use for electrical detection and/or manipulation of macromolecules. These applications exploit the changes in signals due to the geometry and electrical properties of the molecular species found within the nanopore. The sensitivity and resolution of such measurements are also influenced by the geometric and electrical properties of the nanopore. This paper continues the development of an analytical theory to predict the electrochemical impedance spectra of nanopores by including the influence of the presence of an unfolded protein using the variable topology finite Warburg impedance model previously published by the authors. The local excluded volume of, and charges present on, the segment of protein sampled by the nanopore are shown to influence the shape and peak frequency of the electrochemical impedance spectrum. An analytical theory is used to relate the capacitive response of the electrical double layer at the surface of the protein to both the charge density at the protein surface and the more commonly measured zeta potential. Illustrative examples show how the theory predicts that the varying sequential regions of surface charge density and excluded volume dictated by the protein primary structure may allow for an impedance-based approach to identifying unfolded proteins.

AB - Single solid-state nanopores find increasing use for electrical detection and/or manipulation of macromolecules. These applications exploit the changes in signals due to the geometry and electrical properties of the molecular species found within the nanopore. The sensitivity and resolution of such measurements are also influenced by the geometric and electrical properties of the nanopore. This paper continues the development of an analytical theory to predict the electrochemical impedance spectra of nanopores by including the influence of the presence of an unfolded protein using the variable topology finite Warburg impedance model previously published by the authors. The local excluded volume of, and charges present on, the segment of protein sampled by the nanopore are shown to influence the shape and peak frequency of the electrochemical impedance spectrum. An analytical theory is used to relate the capacitive response of the electrical double layer at the surface of the protein to both the charge density at the protein surface and the more commonly measured zeta potential. Illustrative examples show how the theory predicts that the varying sequential regions of surface charge density and excluded volume dictated by the protein primary structure may allow for an impedance-based approach to identifying unfolded proteins.

UR - http://www.scopus.com/inward/record.url?scp=84884875488&partnerID=8YFLogxK

U2 - 10.1063/1.4819470

DO - 10.1063/1.4819470

M3 - Article

VL - 139

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 10

M1 - 105101

ER -