Tethered Bilayer Membranes Containing Ionic Reservoirs:  The Interfacial Capacitance

The use of polar linkers to tether lipid bilayer membranes to a gold substrate results in a hydrophilic layer between the membrane and the gold surface. The tethering of lipid bilayer membranes to gold substrates using tetraethylene glycol chains results in a polar layer between the membrane and the...

Full description

Saved in:
Bibliographic Details
Published in:Langmuir 2001-08, Vol.17 (16), p.4858-4866
Main Authors: Krishna, Gowri, Schulte, Jurgen, Cornell, Bruce A, Pace, Ron, Wieczorek, Lech, Osman, Peter D
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
cited_by cdi_FETCH-LOGICAL-a361t-da792f68a5ecf17142cea9a202decf5524a13bda9ccdfdd6a95d6fff8f0697663
cites cdi_FETCH-LOGICAL-a361t-da792f68a5ecf17142cea9a202decf5524a13bda9ccdfdd6a95d6fff8f0697663
container_end_page 4866
container_issue 16
container_start_page 4858
container_title Langmuir
container_volume 17
creator Krishna, Gowri
Schulte, Jurgen
Cornell, Bruce A
Pace, Ron
Wieczorek, Lech
Osman, Peter D
description The use of polar linkers to tether lipid bilayer membranes to a gold substrate results in a hydrophilic layer between the membrane and the gold surface. The tethering of lipid bilayer membranes to gold substrates using tetraethylene glycol chains results in a polar layer between the membrane and the gold surface. This region may sequester ions and can act as a reservoir for ions transported across the tethered lipid membrane. In the present article, we report on the electrical properties of this ionic reservoir. In particular, the Stern model of ionic distribution is used to describe the interfacial capacitance. The model combines a surface adsorption layer (Helmholtz model) and a dynamic diffuse layer of ions (Gouy−Chapman model) to describe the interfacial capacitance. This model is used to interpret data from measurements of the interfacial capacitance obtained over a range of ionic species and concentrations. Four analogues of the sulfur−tetraethylene glycol tethers have been investigated. These studies show the effects of varying the structure of the linker group and of introducing a passivation layer adjacent to the gold. Studies were also made of the influence of spacer molecules included to vary the “in-plane” two-dimensional packing. The effect of applying a dc bias potential between an external reference electrode and the gold surface was also studied. These measurements were carried out using ac impedance spectroscopy on bilayers assembled using the method of Cornell et al. Most data are successfully modeled as a constant Helmholtz capacitance in series with a diffuse region capacitance that depends on ionic concentration. The dependence on ionic concentration has been modeled by the Gouy−Chapman formalism. At low ionic concentrations (
doi_str_mv 10.1021/la001480a
format article
fullrecord <record><control><sourceid>acs_cross</sourceid><recordid>TN_cdi_crossref_primary_10_1021_la001480a</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><sourcerecordid>a529969751</sourcerecordid><originalsourceid>FETCH-LOGICAL-a361t-da792f68a5ecf17142cea9a202decf5524a13bda9ccdfdd6a95d6fff8f0697663</originalsourceid><addsrcrecordid>eNpt0LtOwzAUBmALgUQpDLyBFwaGgO0kdsJGw6VVi0AQKjbr1BeaEpzKDohurLwmT0JQUSemc3T06ZfOj9AhJSeUMHpaAyE0yQhsoR5NGYnSjIlt1CMiiSOR8HgX7YWwIITkcZL30LQ07dx4o_GgqmFlPL4xrzMPzgRcNK6FylXuGY8aVyl8b4Lx703lw9n35xcu5waPXGu8BVVBjQtYdksLTpl9tGOhDubgb_bR49VlWQyjye31qDifRBBz2kYaRM4szyA1ylJBE6YM5MAI090hTVkCNJ5pyJXSVmsOeaq5tTazhOeC87iPjte5yjcheGPl0lev4FeSEvlbiNwU0tlobavQmo8NBP8iuYhFKsu7B_k0LgYX0-FY0s4frT2oIBfNm3fdJ__k_gDRYXDG</addsrcrecordid><sourcetype>Aggregation Database</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype></control><display><type>article</type><title>Tethered Bilayer Membranes Containing Ionic Reservoirs:  The Interfacial Capacitance</title><source>American Chemical Society:Jisc Collections:American Chemical Society Read &amp; Publish Agreement 2022-2024 (Reading list)</source><creator>Krishna, Gowri ; Schulte, Jurgen ; Cornell, Bruce A ; Pace, Ron ; Wieczorek, Lech ; Osman, Peter D</creator><creatorcontrib>Krishna, Gowri ; Schulte, Jurgen ; Cornell, Bruce A ; Pace, Ron ; Wieczorek, Lech ; Osman, Peter D</creatorcontrib><description>The use of polar linkers to tether lipid bilayer membranes to a gold substrate results in a hydrophilic layer between the membrane and the gold surface. The tethering of lipid bilayer membranes to gold substrates using tetraethylene glycol chains results in a polar layer between the membrane and the gold surface. This region may sequester ions and can act as a reservoir for ions transported across the tethered lipid membrane. In the present article, we report on the electrical properties of this ionic reservoir. In particular, the Stern model of ionic distribution is used to describe the interfacial capacitance. The model combines a surface adsorption layer (Helmholtz model) and a dynamic diffuse layer of ions (Gouy−Chapman model) to describe the interfacial capacitance. This model is used to interpret data from measurements of the interfacial capacitance obtained over a range of ionic species and concentrations. Four analogues of the sulfur−tetraethylene glycol tethers have been investigated. These studies show the effects of varying the structure of the linker group and of introducing a passivation layer adjacent to the gold. Studies were also made of the influence of spacer molecules included to vary the “in-plane” two-dimensional packing. The effect of applying a dc bias potential between an external reference electrode and the gold surface was also studied. These measurements were carried out using ac impedance spectroscopy on bilayers assembled using the method of Cornell et al. Most data are successfully modeled as a constant Helmholtz capacitance in series with a diffuse region capacitance that depends on ionic concentration. The dependence on ionic concentration has been modeled by the Gouy−Chapman formalism. At low ionic concentrations (&lt;20 mM), the model becomes inadequate. Deviation from the model also occurs at higher concentrations for more tightly packed membranes, in the absence of tethered spacer molecules. According to the model at very low concentrations of electrolyte, the ionic Debye length intrudes into the hydrocarbon region of the bilayer, violating the Gouy−Chapman assumption of a uniform dielectric medium in the diffuse double layer. The Helmholtz capacitance is insensitive to potential and ionic concentration. This is consistent with Helmholtz capacitance being defined by a hard sphere distance of closest approach of the ions to the gold interface over the range of concentrations studied here. The model suggests that the application of a dc potential alters the permittivity of the diffuse region as a result of water and ions being transported into the reservoir. However, the effective relative permittivity in the reservoir region varies only from 27 to 54, suggesting the reservoir has properties more akin to a dense hydrated gel with restricted ionic mobility than to a bulk electrolyte.</description><identifier>ISSN: 0743-7463</identifier><identifier>EISSN: 1520-5827</identifier><identifier>DOI: 10.1021/la001480a</identifier><language>eng</language><publisher>American Chemical Society</publisher><ispartof>Langmuir, 2001-08, Vol.17 (16), p.4858-4866</ispartof><rights>Copyright © 2001 American Chemical Society</rights><lds50>peer_reviewed</lds50><woscitedreferencessubscribed>false</woscitedreferencessubscribed><citedby>FETCH-LOGICAL-a361t-da792f68a5ecf17142cea9a202decf5524a13bda9ccdfdd6a95d6fff8f0697663</citedby><cites>FETCH-LOGICAL-a361t-da792f68a5ecf17142cea9a202decf5524a13bda9ccdfdd6a95d6fff8f0697663</cites></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><link.rule.ids>314,780,784,27923,27924</link.rule.ids></links><search><creatorcontrib>Krishna, Gowri</creatorcontrib><creatorcontrib>Schulte, Jurgen</creatorcontrib><creatorcontrib>Cornell, Bruce A</creatorcontrib><creatorcontrib>Pace, Ron</creatorcontrib><creatorcontrib>Wieczorek, Lech</creatorcontrib><creatorcontrib>Osman, Peter D</creatorcontrib><title>Tethered Bilayer Membranes Containing Ionic Reservoirs:  The Interfacial Capacitance</title><title>Langmuir</title><addtitle>Langmuir</addtitle><description>The use of polar linkers to tether lipid bilayer membranes to a gold substrate results in a hydrophilic layer between the membrane and the gold surface. The tethering of lipid bilayer membranes to gold substrates using tetraethylene glycol chains results in a polar layer between the membrane and the gold surface. This region may sequester ions and can act as a reservoir for ions transported across the tethered lipid membrane. In the present article, we report on the electrical properties of this ionic reservoir. In particular, the Stern model of ionic distribution is used to describe the interfacial capacitance. The model combines a surface adsorption layer (Helmholtz model) and a dynamic diffuse layer of ions (Gouy−Chapman model) to describe the interfacial capacitance. This model is used to interpret data from measurements of the interfacial capacitance obtained over a range of ionic species and concentrations. Four analogues of the sulfur−tetraethylene glycol tethers have been investigated. These studies show the effects of varying the structure of the linker group and of introducing a passivation layer adjacent to the gold. Studies were also made of the influence of spacer molecules included to vary the “in-plane” two-dimensional packing. The effect of applying a dc bias potential between an external reference electrode and the gold surface was also studied. These measurements were carried out using ac impedance spectroscopy on bilayers assembled using the method of Cornell et al. Most data are successfully modeled as a constant Helmholtz capacitance in series with a diffuse region capacitance that depends on ionic concentration. The dependence on ionic concentration has been modeled by the Gouy−Chapman formalism. At low ionic concentrations (&lt;20 mM), the model becomes inadequate. Deviation from the model also occurs at higher concentrations for more tightly packed membranes, in the absence of tethered spacer molecules. According to the model at very low concentrations of electrolyte, the ionic Debye length intrudes into the hydrocarbon region of the bilayer, violating the Gouy−Chapman assumption of a uniform dielectric medium in the diffuse double layer. The Helmholtz capacitance is insensitive to potential and ionic concentration. This is consistent with Helmholtz capacitance being defined by a hard sphere distance of closest approach of the ions to the gold interface over the range of concentrations studied here. The model suggests that the application of a dc potential alters the permittivity of the diffuse region as a result of water and ions being transported into the reservoir. However, the effective relative permittivity in the reservoir region varies only from 27 to 54, suggesting the reservoir has properties more akin to a dense hydrated gel with restricted ionic mobility than to a bulk electrolyte.</description><issn>0743-7463</issn><issn>1520-5827</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2001</creationdate><recordtype>article</recordtype><recordid>eNpt0LtOwzAUBmALgUQpDLyBFwaGgO0kdsJGw6VVi0AQKjbr1BeaEpzKDohurLwmT0JQUSemc3T06ZfOj9AhJSeUMHpaAyE0yQhsoR5NGYnSjIlt1CMiiSOR8HgX7YWwIITkcZL30LQ07dx4o_GgqmFlPL4xrzMPzgRcNK6FylXuGY8aVyl8b4Lx703lw9n35xcu5waPXGu8BVVBjQtYdksLTpl9tGOhDubgb_bR49VlWQyjye31qDifRBBz2kYaRM4szyA1ylJBE6YM5MAI090hTVkCNJ5pyJXSVmsOeaq5tTazhOeC87iPjte5yjcheGPl0lev4FeSEvlbiNwU0tlobavQmo8NBP8iuYhFKsu7B_k0LgYX0-FY0s4frT2oIBfNm3fdJ__k_gDRYXDG</recordid><startdate>20010807</startdate><enddate>20010807</enddate><creator>Krishna, Gowri</creator><creator>Schulte, Jurgen</creator><creator>Cornell, Bruce A</creator><creator>Pace, Ron</creator><creator>Wieczorek, Lech</creator><creator>Osman, Peter D</creator><general>American Chemical Society</general><scope>BSCLL</scope><scope>AAYXX</scope><scope>CITATION</scope></search><sort><creationdate>20010807</creationdate><title>Tethered Bilayer Membranes Containing Ionic Reservoirs:  The Interfacial Capacitance</title><author>Krishna, Gowri ; Schulte, Jurgen ; Cornell, Bruce A ; Pace, Ron ; Wieczorek, Lech ; Osman, Peter D</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-a361t-da792f68a5ecf17142cea9a202decf5524a13bda9ccdfdd6a95d6fff8f0697663</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>2001</creationdate><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Krishna, Gowri</creatorcontrib><creatorcontrib>Schulte, Jurgen</creatorcontrib><creatorcontrib>Cornell, Bruce A</creatorcontrib><creatorcontrib>Pace, Ron</creatorcontrib><creatorcontrib>Wieczorek, Lech</creatorcontrib><creatorcontrib>Osman, Peter D</creatorcontrib><collection>Istex</collection><collection>CrossRef</collection><jtitle>Langmuir</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>Krishna, Gowri</au><au>Schulte, Jurgen</au><au>Cornell, Bruce A</au><au>Pace, Ron</au><au>Wieczorek, Lech</au><au>Osman, Peter D</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Tethered Bilayer Membranes Containing Ionic Reservoirs:  The Interfacial Capacitance</atitle><jtitle>Langmuir</jtitle><addtitle>Langmuir</addtitle><date>2001-08-07</date><risdate>2001</risdate><volume>17</volume><issue>16</issue><spage>4858</spage><epage>4866</epage><pages>4858-4866</pages><issn>0743-7463</issn><eissn>1520-5827</eissn><abstract>The use of polar linkers to tether lipid bilayer membranes to a gold substrate results in a hydrophilic layer between the membrane and the gold surface. The tethering of lipid bilayer membranes to gold substrates using tetraethylene glycol chains results in a polar layer between the membrane and the gold surface. This region may sequester ions and can act as a reservoir for ions transported across the tethered lipid membrane. In the present article, we report on the electrical properties of this ionic reservoir. In particular, the Stern model of ionic distribution is used to describe the interfacial capacitance. The model combines a surface adsorption layer (Helmholtz model) and a dynamic diffuse layer of ions (Gouy−Chapman model) to describe the interfacial capacitance. This model is used to interpret data from measurements of the interfacial capacitance obtained over a range of ionic species and concentrations. Four analogues of the sulfur−tetraethylene glycol tethers have been investigated. These studies show the effects of varying the structure of the linker group and of introducing a passivation layer adjacent to the gold. Studies were also made of the influence of spacer molecules included to vary the “in-plane” two-dimensional packing. The effect of applying a dc bias potential between an external reference electrode and the gold surface was also studied. These measurements were carried out using ac impedance spectroscopy on bilayers assembled using the method of Cornell et al. Most data are successfully modeled as a constant Helmholtz capacitance in series with a diffuse region capacitance that depends on ionic concentration. The dependence on ionic concentration has been modeled by the Gouy−Chapman formalism. At low ionic concentrations (&lt;20 mM), the model becomes inadequate. Deviation from the model also occurs at higher concentrations for more tightly packed membranes, in the absence of tethered spacer molecules. According to the model at very low concentrations of electrolyte, the ionic Debye length intrudes into the hydrocarbon region of the bilayer, violating the Gouy−Chapman assumption of a uniform dielectric medium in the diffuse double layer. The Helmholtz capacitance is insensitive to potential and ionic concentration. This is consistent with Helmholtz capacitance being defined by a hard sphere distance of closest approach of the ions to the gold interface over the range of concentrations studied here. The model suggests that the application of a dc potential alters the permittivity of the diffuse region as a result of water and ions being transported into the reservoir. However, the effective relative permittivity in the reservoir region varies only from 27 to 54, suggesting the reservoir has properties more akin to a dense hydrated gel with restricted ionic mobility than to a bulk electrolyte.</abstract><pub>American Chemical Society</pub><doi>10.1021/la001480a</doi><tpages>9</tpages></addata></record>
fulltext fulltext
identifier ISSN: 0743-7463
ispartof Langmuir, 2001-08, Vol.17 (16), p.4858-4866
issn 0743-7463
1520-5827
language eng
recordid cdi_crossref_primary_10_1021_la001480a
source American Chemical Society:Jisc Collections:American Chemical Society Read & Publish Agreement 2022-2024 (Reading list)
title Tethered Bilayer Membranes Containing Ionic Reservoirs:  The Interfacial Capacitance
url http://sfxeu10.hosted.exlibrisgroup.com/loughborough?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2025-01-09T06%3A34%3A02IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-acs_cross&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Tethered%20Bilayer%20Membranes%20Containing%20Ionic%20Reservoirs:%E2%80%89%20The%20Interfacial%20Capacitance&rft.jtitle=Langmuir&rft.au=Krishna,%20Gowri&rft.date=2001-08-07&rft.volume=17&rft.issue=16&rft.spage=4858&rft.epage=4866&rft.pages=4858-4866&rft.issn=0743-7463&rft.eissn=1520-5827&rft_id=info:doi/10.1021/la001480a&rft_dat=%3Cacs_cross%3Ea529969751%3C/acs_cross%3E%3Cgrp_id%3Ecdi_FETCH-LOGICAL-a361t-da792f68a5ecf17142cea9a202decf5524a13bda9ccdfdd6a95d6fff8f0697663%3C/grp_id%3E%3Coa%3E%3C/oa%3E%3Curl%3E%3C/url%3E&rft_id=info:oai/&rft_id=info:pmid/&rfr_iscdi=true