Correcting the polarization effect in very low frequency dielectric spectroscopy

Abstract

Abstract. We demonstrate a simple and robust methodology for measuring and analyzing the polarization impedance appearing at interface between electrodes and ionic solutions, in the frequency range from 1 to 10 6 Hz. The method assumes no particular behavior of the electrode polarization impedance and it only makes use of the fact that the polarization effect dies out with frequency. The method allows a direct and un-biased measurement of the polarization impedance, whose behavior with the applied voltages and ionic concentration is methodically investigated. Furthermore, based on the previous findings, we propose a protocol for correcting the polarization effect in low frequency Dielectric Spectroscopy measurements of colloids. This could potentially lead to the quantitative resolution of the α-dispersion regime of live cells in suspension.

Quantifying the membrane potential during E. coli growth stages

“…An efficient method for correcting the polarization effect was developed in Refs. [23,24], which we also follow here. It consists of the following steps:…”

“…[23] and was subsequently applied in Ref. [19] to obtain accurate dielectric measurements on E. coli cell suspensions.…”

On the dielectric relaxation of biological cell suspensions: The effect of the membrane electrical conductivity

“…(16) takes into account the increase in the electrical conductivity at the high frequency tail of the frequency window investigated due to the beginning of the orientational polarization of the aqueous phase. The space charge distribution adjacent to the electrodes, which causes at lower frequencies a large polarization that masks the dielectric response of the sample, has been represented, in terms of lumped circuit element, by a constant-phase-angle [CPA] element, resulting in an admittance Y(ω) = A(iω)ˇ, with A andˇappropriate constants [28][29][30]. As far as the aqueous phase dispersion is concerned, we have assumed a dielectric increment H 2 O = 75.0, a relaxation frequency H 2 O = 17.5 GHz and a spread parameterˇH 2 O = 0.025.…”

Flexible Bioimpedance Sensor for Label-Free Detection of Cell Viability and Biomass

“…By means of adopting a distance variation technique [40] onto our microfluidic device to characterize the dielectric variations occurring in a volume of 1000x1000x70 µm 3 (D70) and 1000x1000x140 µm 3 (D140), we attempt to nullify the effects of stray impedance on our disposable bioimpedance sensor. The proposed sensor is designed to facilitate differential impedance correction with a dual electrode pair arrangement.…”