Infrared spectroscopic characterization of lipid-alkylsiloxane hybrid bilayer membranes at oxide substrates

Atul N. Parikh, Jaime D. Beers, Andrew P. Shreve, Basil I. Swanson

Research output: Contribution to journalArticle

40 Citations (Scopus)

Abstract

Successive depositions of precompressed Langmuir monolayers have been shown to allow reproducible formation of air-stable, lipid-alkylsiloxane hybrid bimolecular architectures at oxidic supports. Specifically, prepolymerized Langmuir-Blodgett films of n-octadecylsiloxane (OTS) monolayers on oxided silicon substrates were used as the hydrophobic templates, upon which compressed monolayers of dipalmitoyl-sn 1-glycerophosphatidylcholine (DPPC) and monosialogangliosides (Gm 1) were deposited from a low-temperature air-water interface by the horizontal deposition method. Structural features of each leaflet of the resultant bimolecular architectures, namely DPPC/OTS/SiO2/Si and Gm1/OTS/SiO2/Si, were characterized using a combined application of infrared spectroscopy, null-ellipsometry, and surface wetting measurements. In both cases, the outer lipid leaflet (DPPC or Gm1) was found to be structurally decoupled with respect to the inner OTS layer. The inner silane layer was composed of essentially untilted (cant angle, θ = 0-10°), all-trans chains at the dense packing of approx. 19 angstrom2/molecule, consistent with the previously reported structure in solution-phase assembled OTS monolayers. The outer DPPC leaflet, however, was found to be composed of collectively tilted (θ = 36°), all-trans acyl chains at the lower chain-packing density (approx. 26-28 angstrom2/chain) whereas the outer Gm1 leaflet was concluded to have essentially untilted chains at similarly lower chain-packing densities (approx. 23-26 angstrom2/chain) but with the carbohydrate head-groups disposed in a topologically staggered conformation. The structural independence of the two leaflets in the two classes of bilayered architectures examined here confirms the possibility of independently manipulating the molecular structure in each leaflet of supported hybrid bilayers.

Original languageEnglish (US)
Pages (from-to)5369-5381
Number of pages13
JournalLangmuir
Volume15
Issue number16
DOIs
StatePublished - Aug 3 1999
Externally publishedYes

Fingerprint

Oxides
Lipids
lipids
Monolayers
membranes
Infrared radiation
Membranes
oxides
Substrates
packing density
Silanes
Langmuir Blodgett films
Ellipsometry
Silicon
Carbohydrates
Air
Molecular structure
Wetting
Conformations
Infrared spectroscopy

ASJC Scopus subject areas

  • Colloid and Surface Chemistry
  • Physical and Theoretical Chemistry

Cite this

Infrared spectroscopic characterization of lipid-alkylsiloxane hybrid bilayer membranes at oxide substrates. / Parikh, Atul N.; Beers, Jaime D.; Shreve, Andrew P.; Swanson, Basil I.

In: Langmuir, Vol. 15, No. 16, 03.08.1999, p. 5369-5381.

Research output: Contribution to journalArticle

Parikh, Atul N. ; Beers, Jaime D. ; Shreve, Andrew P. ; Swanson, Basil I. / Infrared spectroscopic characterization of lipid-alkylsiloxane hybrid bilayer membranes at oxide substrates. In: Langmuir. 1999 ; Vol. 15, No. 16. pp. 5369-5381.
@article{a257eaa0c9034f858bef8f29f470e81e,
title = "Infrared spectroscopic characterization of lipid-alkylsiloxane hybrid bilayer membranes at oxide substrates",
abstract = "Successive depositions of precompressed Langmuir monolayers have been shown to allow reproducible formation of air-stable, lipid-alkylsiloxane hybrid bimolecular architectures at oxidic supports. Specifically, prepolymerized Langmuir-Blodgett films of n-octadecylsiloxane (OTS) monolayers on oxided silicon substrates were used as the hydrophobic templates, upon which compressed monolayers of dipalmitoyl-sn 1-glycerophosphatidylcholine (DPPC) and monosialogangliosides (Gm 1) were deposited from a low-temperature air-water interface by the horizontal deposition method. Structural features of each leaflet of the resultant bimolecular architectures, namely DPPC/OTS/SiO2/Si and Gm1/OTS/SiO2/Si, were characterized using a combined application of infrared spectroscopy, null-ellipsometry, and surface wetting measurements. In both cases, the outer lipid leaflet (DPPC or Gm1) was found to be structurally decoupled with respect to the inner OTS layer. The inner silane layer was composed of essentially untilted (cant angle, θ = 0-10°), all-trans chains at the dense packing of approx. 19 angstrom2/molecule, consistent with the previously reported structure in solution-phase assembled OTS monolayers. The outer DPPC leaflet, however, was found to be composed of collectively tilted (θ = 36°), all-trans acyl chains at the lower chain-packing density (approx. 26-28 angstrom2/chain) whereas the outer Gm1 leaflet was concluded to have essentially untilted chains at similarly lower chain-packing densities (approx. 23-26 angstrom2/chain) but with the carbohydrate head-groups disposed in a topologically staggered conformation. The structural independence of the two leaflets in the two classes of bilayered architectures examined here confirms the possibility of independently manipulating the molecular structure in each leaflet of supported hybrid bilayers.",
author = "Parikh, {Atul N.} and Beers, {Jaime D.} and Shreve, {Andrew P.} and Swanson, {Basil I.}",
year = "1999",
month = "8",
day = "3",
doi = "10.1021/la9813679",
language = "English (US)",
volume = "15",
pages = "5369--5381",
journal = "Langmuir",
issn = "0743-7463",
publisher = "American Chemical Society",
number = "16",

}

TY - JOUR

T1 - Infrared spectroscopic characterization of lipid-alkylsiloxane hybrid bilayer membranes at oxide substrates

AU - Parikh, Atul N.

AU - Beers, Jaime D.

AU - Shreve, Andrew P.

AU - Swanson, Basil I.

PY - 1999/8/3

Y1 - 1999/8/3

N2 - Successive depositions of precompressed Langmuir monolayers have been shown to allow reproducible formation of air-stable, lipid-alkylsiloxane hybrid bimolecular architectures at oxidic supports. Specifically, prepolymerized Langmuir-Blodgett films of n-octadecylsiloxane (OTS) monolayers on oxided silicon substrates were used as the hydrophobic templates, upon which compressed monolayers of dipalmitoyl-sn 1-glycerophosphatidylcholine (DPPC) and monosialogangliosides (Gm 1) were deposited from a low-temperature air-water interface by the horizontal deposition method. Structural features of each leaflet of the resultant bimolecular architectures, namely DPPC/OTS/SiO2/Si and Gm1/OTS/SiO2/Si, were characterized using a combined application of infrared spectroscopy, null-ellipsometry, and surface wetting measurements. In both cases, the outer lipid leaflet (DPPC or Gm1) was found to be structurally decoupled with respect to the inner OTS layer. The inner silane layer was composed of essentially untilted (cant angle, θ = 0-10°), all-trans chains at the dense packing of approx. 19 angstrom2/molecule, consistent with the previously reported structure in solution-phase assembled OTS monolayers. The outer DPPC leaflet, however, was found to be composed of collectively tilted (θ = 36°), all-trans acyl chains at the lower chain-packing density (approx. 26-28 angstrom2/chain) whereas the outer Gm1 leaflet was concluded to have essentially untilted chains at similarly lower chain-packing densities (approx. 23-26 angstrom2/chain) but with the carbohydrate head-groups disposed in a topologically staggered conformation. The structural independence of the two leaflets in the two classes of bilayered architectures examined here confirms the possibility of independently manipulating the molecular structure in each leaflet of supported hybrid bilayers.

AB - Successive depositions of precompressed Langmuir monolayers have been shown to allow reproducible formation of air-stable, lipid-alkylsiloxane hybrid bimolecular architectures at oxidic supports. Specifically, prepolymerized Langmuir-Blodgett films of n-octadecylsiloxane (OTS) monolayers on oxided silicon substrates were used as the hydrophobic templates, upon which compressed monolayers of dipalmitoyl-sn 1-glycerophosphatidylcholine (DPPC) and monosialogangliosides (Gm 1) were deposited from a low-temperature air-water interface by the horizontal deposition method. Structural features of each leaflet of the resultant bimolecular architectures, namely DPPC/OTS/SiO2/Si and Gm1/OTS/SiO2/Si, were characterized using a combined application of infrared spectroscopy, null-ellipsometry, and surface wetting measurements. In both cases, the outer lipid leaflet (DPPC or Gm1) was found to be structurally decoupled with respect to the inner OTS layer. The inner silane layer was composed of essentially untilted (cant angle, θ = 0-10°), all-trans chains at the dense packing of approx. 19 angstrom2/molecule, consistent with the previously reported structure in solution-phase assembled OTS monolayers. The outer DPPC leaflet, however, was found to be composed of collectively tilted (θ = 36°), all-trans acyl chains at the lower chain-packing density (approx. 26-28 angstrom2/chain) whereas the outer Gm1 leaflet was concluded to have essentially untilted chains at similarly lower chain-packing densities (approx. 23-26 angstrom2/chain) but with the carbohydrate head-groups disposed in a topologically staggered conformation. The structural independence of the two leaflets in the two classes of bilayered architectures examined here confirms the possibility of independently manipulating the molecular structure in each leaflet of supported hybrid bilayers.

UR - http://www.scopus.com/inward/record.url?scp=0032659434&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032659434&partnerID=8YFLogxK

U2 - 10.1021/la9813679

DO - 10.1021/la9813679

M3 - Article

VL - 15

SP - 5369

EP - 5381

JO - Langmuir

JF - Langmuir

SN - 0743-7463

IS - 16

ER -