Electrical Impedance Analysis of Phospholipid Bilayer Membranes for Enabling Engineering Design of Bio-based Devices

2007 ◽  
Vol 1061 ◽  
Author(s):  
Stephen A. Sarles ◽  
Vishnu B. Sundaresan ◽  
Donald J. Leo
Keyword(s):  
Lipid Membranes ◽  
Electrical Impedance ◽  
Lipid Membrane ◽  
Electrical Power ◽  
Impedance Analysis ◽  
Electrical Impedance Spectroscopy ◽  
Phospholipid Bilayer ◽  
Silicon Substrates ◽  
Bilayer Membranes ◽  
Single Aperture

ABSTRACTRecent research at Virginia Tech have shown that active transporter proteins reconstituted into suspended bilayer lipid membranes (BLMs) formed across an array of pores in synthetic substrates can convert chemical energy available in adenosine triphosphate (ATP) into electricity. Experimental results from this work show that this system—called BioCell—is capable of 1.7μW of electrical power per square centimeter of BLM area and per 15μL of ATPase enzyme. In support of such a system, the lipid membrane, as host to active biological proteins and channels, must be formed evenly across a porous substrate, remain stable and yet fluid-like for protein folding and activation, and provide sufficient electrical insulation. We report on the formation and characterization using electrical impedance spectroscopy (EIS) of BLMs formed across two types of porous substrates: polycarbonate filters and single-aperture silicon substrates. Equivalent electrical circuits describing the lipid membranes and their supporting substrates are approximated to fit the measured responses. The results show that BLMs formed in some but not all of the 400nm pores of the filters, while the formation of BLMs on the single-aperture silicon substrates was much more consistent.

Voltage-dependent gating properties of the channel formed by E. coli hemolysin in planar lipid membranes

1989 ◽  
Vol 9 (4) ◽  
pp. 465-473 ◽  
Author(s):  
Gianfranco Menestrina ◽  
Monica Ropele
Keyword(s):  
Lipid Membranes ◽  
Ph Dependence ◽  
Phospholipid Bilayer ◽  
Bilayer Membranes ◽  
E Coli ◽  
Simple Physical Model ◽  
Voltage Dependent ◽  
Planar Lipid Membranes ◽  
Escherichia Coli Hemolysin ◽  
Gating Process

Escherichia coli hemolysin forms cation selective, ion-permeable channels of large conductance in planar phospholipid bilayer membranes. The pore formation mechanism is voltage dependent resembling that of some colicins and of diphtheria toxin: pores open when negative voltages are applied and close with positive potentials. The pH dependence of this gating process suggests that it is mediated by a negative fixed charge present in the lumen of the pore. A simple physical model of how the channel opens and closes in response to the applied voltage is given.

scholarly journals Assessing the supercooling of fresh-cut onions at −5°C using electrical impedance analysis

2020 ◽  
Vol 4 (2) ◽  
pp. 55-58
Author(s):  
Shoji Koide ◽  
Ami Yoneyama ◽  
Takahiro Orikasa ◽  
Matsuo Uemura
Keyword(s):  
Cell Membrane ◽  
Electrical Impedance ◽  
Freezing Point ◽  
Impedance Analysis ◽  
Electrical Impedance Spectroscopy ◽  
Cole Plot ◽  
Supercooling Point ◽  
Circular Arc ◽  
Two Samples ◽  
Fresh Cut

Abstract We supercooled fresh-cut onion at −5°C for 12 h. After supercooling, the electric impedance properties of the samples were evaluated by electrical impedance spectroscopy over the frequency range of 42 Hz − 5 MHz. The time-temperature profiles of samples indicated that the freezing point and supercooling point were −2.3°C ± 0.7°C and −6.9°C ± 1.0°C, respectively. The results indicated that 34 of the 36 supercooled samples exhibited a definite circular arc in the Cole-Cole plot, which suggested that the cell membrane remained intact during supercooling. In the other two samples which did not exhibit a definite circular arc, the cell membrane had sustained serious damage during supercooling. Furthermore, there was large difference in drip loss percentage between supercooled samples exhibited a definite circular arc in the Cole-Cole plot and samples not exhibiting a definite circular arc. Our results suggest that fresh-cut onions can be supercooled at −5°C.

Polypyrrole Bridge as a Support for Alamethicin-Reconstituted Planar Bilayer Lipid Membranes

2011 ◽  
Author(s):  
Robert Northcutt ◽  
Vishnu-Baba Sundaresan ◽  
Sergio Salinas ◽  
Hao Zhang
Keyword(s):  
Ion Transport ◽  
Conducting Polymer ◽  
Lipid Membranes ◽  
Lipid Membrane ◽  
Active Material ◽  
Experimental Studies ◽  
Bilayer Lipid Membrane ◽  
Electrical Impedance Spectroscopy ◽  
Bilayer Lipid ◽  
Ionic Components

Conducting polymer actuators and sensors utilize electrochemical reactions and associated ion transport at the polymer-electrolyte interface for their engineering function. Similarly, a bioderived active material utilizes ion transport through a protein and across a bilayer lipid membrane for sensing and actuation functions. Inspired by the similarity in ion transport process in a bilayer lipid membrane (BLM) and conducting polymers, we propose to build an integrated ionic device in which the ion transport through the protein in the bilayer lipid membrane regulates the electrolytic and mechanical properties of the conducting polymer. This article demonstrates the fabrication and characterization of a DPhPC planar BLM reconstituted with alamethicin and supported on a polypyrrole bridge measuring 100 μm × 500 μm and formed across micro-fabricated gold pads. The assembly is supported on silicon dioxide coated wafers and packaged into an electronic-ionic package for electrochemical characterization. The various ionic components in the integrated ionic device are characterized using electrical impedance spectroscopy (EIS), cyclic voltammetry (CV), and chronoamperometry (CA) measurements. The results from our experimental studies demonstrate the procedure to fabricate a rugged electro active polymer supported BLM that will serve as a platform for chemical, bioelectrical sensing and VOC detection.

scholarly journals Bioelectrical Impedance Methods for Noninvasive Health Monitoring: A Review

2014 ◽  
Vol 2014 ◽  
pp. 1-28 ◽  
Author(s):  
Tushar Kanti Bera
Keyword(s):  
Electrical Impedance ◽  
Tissue Characterization ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
Biological Tissues ◽  
Disease Diagnosis ◽  
Impedance Plethysmography ◽  
Electrical Impedance Spectroscopy ◽  
Signal Frequency ◽  
Impedance Tomography

Under the alternating electrical excitation, biological tissues produce a complex electrical impedance which depends on tissue composition, structures, health status, and applied signal frequency, and hence the bioelectrical impedance methods can be utilized for noninvasive tissue characterization. As the impedance responses of these tissue parameters vary with frequencies of the applied signal, the impedance analysis conducted over a wide frequency band provides more information about the tissue interiors which help us to better understand the biological tissues anatomy, physiology, and pathology. Over past few decades, a number of impedance based noninvasive tissue characterization techniques such as bioelectrical impedance analysis (BIA), electrical impedance spectroscopy (EIS), electrical impedance plethysmography (IPG), impedance cardiography (ICG), and electrical impedance tomography (EIT) have been proposed and a lot of research works have been conducted on these methods for noninvasive tissue characterization and disease diagnosis. In this paper BIA, EIS, IPG, ICG, and EIT techniques and their applications in different fields have been reviewed and technical perspective of these impedance methods has been presented. The working principles, applications, merits, and demerits of these methods has been discussed in detail along with their other technical issues followed by present status and future trends.

scholarly journals Electrochemical Properties of Lipid Membranes Self-Assembled from Bicelles

Membranes ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 11
Author(s):  
Damian Dziubak ◽  
Kamil Strzelak ◽  
Slawomir Sek
Keyword(s):  
Electrochemical Properties ◽  
Self Assembly ◽  
Lipid Membranes ◽  
Lipid Membrane ◽  
Membrane Resistance ◽  
Electrochemical Characteristics ◽  
Freeze Thaw ◽  
Lipid Films ◽  
Supported Lipid Membranes

Supported lipid membranes are widely used platforms which serve as simplified models of cell membranes. Among numerous methods used for preparation of planar lipid films, self-assembly of bicelles appears to be promising strategy. Therefore, in this paper we have examined the mechanism of formation and the electrochemical properties of lipid films deposited onto thioglucose-modified gold electrodes from bicellar mixtures. It was found that adsorption of the bicelles occurs by replacement of interfacial water and it leads to formation of a double bilayer structure on the electrode surface. The resulting lipid assembly contains numerous defects and pinholes which affect the permeability of the membrane for ions and water. Significant improvement in morphology and electrochemical characteristics is achieved upon freeze–thaw treatment of the deposited membrane. The lipid assembly is rearranged to single bilayer configuration with locally occurring patches of the second bilayer, and the number of pinholes is substantially decreased. Electrochemical characterization of the lipid membrane after freeze–thaw treatment demonstrated that its permeability for ions and water is significantly reduced, which was manifested by the relatively high value of the membrane resistance.

scholarly journals Monitoring Contractile Cardiomyocytes via Impedance Using Multipurpose Thin Film Ruthenium Oxide Electrodes

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1433
Author(s):  
Esther Tanumihardja ◽  
Douwe S. de Bruijn ◽  
Rolf H. Slaats ◽  
Wouter Olthuis ◽  
Albert van den Berg
Keyword(s):  
Thin Film ◽  
Electrical Impedance ◽  
Ruthenium Oxide ◽  
Electrical Impedance Spectroscopy ◽  
Visual Data ◽  
Oxide Electrodes ◽  
Pt Electrodes ◽  
Mode Of Operation ◽  
Frequency Components

A ruthenium oxide (RuOx) electrode was used to monitor contractile events of human pluripotent stem cells-derived cardiomyocytes (hPSC-CMs) through electrical impedance spectroscopy (EIS). Using RuOx electrodes presents an advantage over standard thin film Pt electrodes because the RuOx electrodes can also be used as electrochemical sensor for pH, O2, and nitric oxide, providing multisensory functionality with the same electrode. First, the EIS signal was validated in an optically transparent well-plate setup using Pt wire electrodes. This way, visual data could be recorded simultaneously. Frequency analyses of both EIS and the visual data revealed almost identical frequency components. This suggests both the EIS and visual data captured the similar events of the beating of (an area of) hPSC-CMs. Similar EIS measurement was then performed using the RuOx electrode, which yielded comparable signal and periodicity. This mode of operation adds to the versatility of the RuOx electrode’s use in in vitro studies.

A Rapid Approach to Measure Extracted Chlorophyll-a from Lettuce Leaves using Electrical Impedance Spectroscopy

2021 ◽  
Vol 232 (2) ◽  
Author(s):  
Rakibul Islam Chowdhury ◽  
Rinku Basak ◽  
Khan Arif Wahid ◽  
Katy Nugent ◽  
Helen Baulch
Keyword(s):  
Impedance Spectroscopy ◽  
Chlorophyll A ◽  
Electrical Impedance ◽  
Electrical Impedance Spectroscopy

scholarly journals Study of Reduced Graphene Oxide Dispersions via Electrical Impedance Spectroscopy

2020 ◽  
Vol 28 ◽  
pp. 1679-1685
Author(s):  
Angeliki-Eirini Dimou ◽  
Ioanna Sakellariou ◽  
George M. Maistros ◽  
Nikolaos D. Alexopoulos
Keyword(s):  
Graphene Oxide ◽  
Impedance Spectroscopy ◽  
Reduced Graphene Oxide ◽  
Electrical Impedance ◽  
Electrical Impedance Spectroscopy ◽  
Reduced Graphene
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