Refractive index and thickness determination in Langmuir monolayers of myelin lipids

Autores
Pusterla, Julio Martín; Malfatti-Gasperini, Antonio A.; Puentes-Martinez, Ximena E.; Cavalcanti, Leide P.; Oliveira, Rafael Gustavo
Año de publicación
2017
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Langmuir monolayers at the air/water interface are widely used as biomembrane models and for amphiphilic molecules studies in general. Under controlled intermolecular organization (lateral molecular area), surface pressure, surface potential, reflectivity (R) and other magnitudes can be precisely determined on these planar monomolecular films. However, some physical parameters such as the refractive index of the monolayer (n) still remain elusive. The refractive index is very relevant because (in combination with R) it allows for the determination of the thickness of the film. The uncertainties of n determine important errors that propagate non-linearly into the calculation of monolayers thickness. Here we present an analytical method for the determination of n in monolayers based on refractive index matching. By using a Brewster angle microscopy (BAM) setup and monolayers spread over subphases with variable refractive index (n2), a minimum in R is search as a function of n2. In these conditions, n equals n2. The results shown correspond to monolayers of myelin lipids. The n values remain constant at 1.46 upon compression and equals the obtained value for myelin lipid bilayers in suspension. The values for n and R allow for the determination of thickness. We establish comparisons between these thicknesses for the monolayer and those obtained from two X-ray scattering techniques: 1) GIXOS for monolayers at the air/water interface and 2) SAXS for bilayers in bulk suspension. This allows us to conclude that the thickness that we measure by BAM includes the apolar and polar headgroup regions of the monolayer.
Fil: Pusterla, Julio Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; Argentina
Fil: Malfatti-Gasperini, Antonio A.. Centro Nacional de Pesquisa Em Energia E Materiais. Laboratório Nacional de Luz Síncrotron; Brasil
Fil: Puentes-Martinez, Ximena E.. Centro Nacional de Pesquisa Em Energia E Materiais. Laboratório Nacional de Luz Síncrotron; Brasil
Fil: Cavalcanti, Leide P.. Universidade Estadual de Campinas; Brasil. Centro Nacional de Pesquisa Em Energia E Materiais. Laboratório Nacional de Luz Síncrotron; Brasil
Fil: Oliveira, Rafael Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; Argentina
Materia
Brewster Angle Microscopy
Gixos
Langmuir Monolayers
Myelin Lipids
Reflectivity
Refractive Index
Saxs
Thickness
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/57506
Acceder
id CONICETDig_957fc6ca70f5e6eb3f2c614cc9729757
oai_identifier_str oai:ri.conicet.gov.ar:11336/57506
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Refractive index and thickness determination in Langmuir monolayers of myelin lipidsPusterla, Julio MartínMalfatti-Gasperini, Antonio A.Puentes-Martinez, Ximena E.Cavalcanti, Leide P.Oliveira, Rafael GustavoBrewster Angle MicroscopyGixosLangmuir MonolayersMyelin LipidsReflectivityRefractive IndexSaxsThicknesshttps://purl.org/becyt/ford/1.6https://purl.org/becyt/ford/1Langmuir monolayers at the air/water interface are widely used as biomembrane models and for amphiphilic molecules studies in general. Under controlled intermolecular organization (lateral molecular area), surface pressure, surface potential, reflectivity (R) and other magnitudes can be precisely determined on these planar monomolecular films. However, some physical parameters such as the refractive index of the monolayer (n) still remain elusive. The refractive index is very relevant because (in combination with R) it allows for the determination of the thickness of the film. The uncertainties of n determine important errors that propagate non-linearly into the calculation of monolayers thickness. Here we present an analytical method for the determination of n in monolayers based on refractive index matching. By using a Brewster angle microscopy (BAM) setup and monolayers spread over subphases with variable refractive index (n2), a minimum in R is search as a function of n2. In these conditions, n equals n2. The results shown correspond to monolayers of myelin lipids. The n values remain constant at 1.46 upon compression and equals the obtained value for myelin lipid bilayers in suspension. The values for n and R allow for the determination of thickness. We establish comparisons between these thicknesses for the monolayer and those obtained from two X-ray scattering techniques: 1) GIXOS for monolayers at the air/water interface and 2) SAXS for bilayers in bulk suspension. This allows us to conclude that the thickness that we measure by BAM includes the apolar and polar headgroup regions of the monolayer.Fil: Pusterla, Julio Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Malfatti-Gasperini, Antonio A.. Centro Nacional de Pesquisa Em Energia E Materiais. Laboratório Nacional de Luz Síncrotron; BrasilFil: Puentes-Martinez, Ximena E.. Centro Nacional de Pesquisa Em Energia E Materiais. Laboratório Nacional de Luz Síncrotron; BrasilFil: Cavalcanti, Leide P.. Universidade Estadual de Campinas; Brasil. Centro Nacional de Pesquisa Em Energia E Materiais. Laboratório Nacional de Luz Síncrotron; BrasilFil: Oliveira, Rafael Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaElsevier Science2017-05info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/57506Pusterla, Julio Martín; Malfatti-Gasperini, Antonio A.; Puentes-Martinez, Ximena E.; Cavalcanti, Leide P.; Oliveira, Rafael Gustavo; Refractive index and thickness determination in Langmuir monolayers of myelin lipids; Elsevier Science; Biochimica et Biophysica Acta - Biomembranes; 1859; 5; 5-2017; 924-9300005-2736CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S0005273617300597info:eu-repo/semantics/altIdentifier/doi/10.1016/j.bbamem.2017.02.005info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-10-15T14:42:56Zoai:ri.conicet.gov.ar:11336/57506instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-10-15 14:42:56.373CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Refractive index and thickness determination in Langmuir monolayers of myelin lipids
title Refractive index and thickness determination in Langmuir monolayers of myelin lipids
spellingShingle Refractive index and thickness determination in Langmuir monolayers of myelin lipids
Pusterla, Julio Martín
Brewster Angle Microscopy
Gixos
Langmuir Monolayers
Myelin Lipids
Reflectivity
Refractive Index
Saxs
Thickness
title_short Refractive index and thickness determination in Langmuir monolayers of myelin lipids
title_full Refractive index and thickness determination in Langmuir monolayers of myelin lipids
title_fullStr Refractive index and thickness determination in Langmuir monolayers of myelin lipids
title_full_unstemmed Refractive index and thickness determination in Langmuir monolayers of myelin lipids
title_sort Refractive index and thickness determination in Langmuir monolayers of myelin lipids
dc.creator.none.fl_str_mv Pusterla, Julio Martín
Malfatti-Gasperini, Antonio A.
Puentes-Martinez, Ximena E.
Cavalcanti, Leide P.
Oliveira, Rafael Gustavo
author Pusterla, Julio Martín
author_facet Pusterla, Julio Martín
Malfatti-Gasperini, Antonio A.
Puentes-Martinez, Ximena E.
Cavalcanti, Leide P.
Oliveira, Rafael Gustavo
author_role author
author2 Malfatti-Gasperini, Antonio A.
Puentes-Martinez, Ximena E.
Cavalcanti, Leide P.
Oliveira, Rafael Gustavo
author2_role author
author
author
author
dc.subject.none.fl_str_mv Brewster Angle Microscopy
Gixos
Langmuir Monolayers
Myelin Lipids
Reflectivity
Refractive Index
Saxs
Thickness
topic Brewster Angle Microscopy
Gixos
Langmuir Monolayers
Myelin Lipids
Reflectivity
Refractive Index
Saxs
Thickness
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Langmuir monolayers at the air/water interface are widely used as biomembrane models and for amphiphilic molecules studies in general. Under controlled intermolecular organization (lateral molecular area), surface pressure, surface potential, reflectivity (R) and other magnitudes can be precisely determined on these planar monomolecular films. However, some physical parameters such as the refractive index of the monolayer (n) still remain elusive. The refractive index is very relevant because (in combination with R) it allows for the determination of the thickness of the film. The uncertainties of n determine important errors that propagate non-linearly into the calculation of monolayers thickness. Here we present an analytical method for the determination of n in monolayers based on refractive index matching. By using a Brewster angle microscopy (BAM) setup and monolayers spread over subphases with variable refractive index (n2), a minimum in R is search as a function of n2. In these conditions, n equals n2. The results shown correspond to monolayers of myelin lipids. The n values remain constant at 1.46 upon compression and equals the obtained value for myelin lipid bilayers in suspension. The values for n and R allow for the determination of thickness. We establish comparisons between these thicknesses for the monolayer and those obtained from two X-ray scattering techniques: 1) GIXOS for monolayers at the air/water interface and 2) SAXS for bilayers in bulk suspension. This allows us to conclude that the thickness that we measure by BAM includes the apolar and polar headgroup regions of the monolayer.
Fil: Pusterla, Julio Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; Argentina
Fil: Malfatti-Gasperini, Antonio A.. Centro Nacional de Pesquisa Em Energia E Materiais. Laboratório Nacional de Luz Síncrotron; Brasil
Fil: Puentes-Martinez, Ximena E.. Centro Nacional de Pesquisa Em Energia E Materiais. Laboratório Nacional de Luz Síncrotron; Brasil
Fil: Cavalcanti, Leide P.. Universidade Estadual de Campinas; Brasil. Centro Nacional de Pesquisa Em Energia E Materiais. Laboratório Nacional de Luz Síncrotron; Brasil
Fil: Oliveira, Rafael Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; Argentina
description Langmuir monolayers at the air/water interface are widely used as biomembrane models and for amphiphilic molecules studies in general. Under controlled intermolecular organization (lateral molecular area), surface pressure, surface potential, reflectivity (R) and other magnitudes can be precisely determined on these planar monomolecular films. However, some physical parameters such as the refractive index of the monolayer (n) still remain elusive. The refractive index is very relevant because (in combination with R) it allows for the determination of the thickness of the film. The uncertainties of n determine important errors that propagate non-linearly into the calculation of monolayers thickness. Here we present an analytical method for the determination of n in monolayers based on refractive index matching. By using a Brewster angle microscopy (BAM) setup and monolayers spread over subphases with variable refractive index (n2), a minimum in R is search as a function of n2. In these conditions, n equals n2. The results shown correspond to monolayers of myelin lipids. The n values remain constant at 1.46 upon compression and equals the obtained value for myelin lipid bilayers in suspension. The values for n and R allow for the determination of thickness. We establish comparisons between these thicknesses for the monolayer and those obtained from two X-ray scattering techniques: 1) GIXOS for monolayers at the air/water interface and 2) SAXS for bilayers in bulk suspension. This allows us to conclude that the thickness that we measure by BAM includes the apolar and polar headgroup regions of the monolayer.
publishDate 2017
dc.date.none.fl_str_mv 2017-05
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/57506
Pusterla, Julio Martín; Malfatti-Gasperini, Antonio A.; Puentes-Martinez, Ximena E.; Cavalcanti, Leide P.; Oliveira, Rafael Gustavo; Refractive index and thickness determination in Langmuir monolayers of myelin lipids; Elsevier Science; Biochimica et Biophysica Acta - Biomembranes; 1859; 5; 5-2017; 924-930
0005-2736
CONICET Digital
CONICET
url http://hdl.handle.net/11336/57506
identifier_str_mv Pusterla, Julio Martín; Malfatti-Gasperini, Antonio A.; Puentes-Martinez, Ximena E.; Cavalcanti, Leide P.; Oliveira, Rafael Gustavo; Refractive index and thickness determination in Langmuir monolayers of myelin lipids; Elsevier Science; Biochimica et Biophysica Acta - Biomembranes; 1859; 5; 5-2017; 924-930
0005-2736
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S0005273617300597
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.bbamem.2017.02.005
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv Elsevier Science
publisher.none.fl_str_mv Elsevier Science
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
_version_ 1846082932786069504
score 13.22299

Publicaciones similares