Imaging nanometer scale optical heterogeneities in phospholipid monolayers deposited on metal island films.
Near-field scanning optical microscopy was applied to study the distribution of fluorescently labeled phospholipid monolayers deposited on the surface of gold island films by the Langmuir-Blodgett technique. Nanometer scale (approximately 50 nm) optical heterogeneities were observed in near-field fluorescence images of the monolayer deposited at 10 mN/m surface pressure. At higher surface pressure (30 mN/m) the heterogeneities became less pronounced. Overlaying of the near-field transmission and fluorescence images from the same area of the sample shows local transmission of gold island film is at a minimum where the fluorescence of the lipid monolayer is at a maximum. It was concluded that coverage of the metal island film by the Langmuir-Blodgett phospholipid monolayer is incomplete, and lipid molecules are preferentially localized in crevices of the film.
Lanoul
Anatoli
A
Department of Chemistry, Carleton University, Ottawa, K1S 5B6, Canada.
Strekal
Natalia
N
Maskevich
Sergei
S
D002784:Cholesterol / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D008670:Metals; D018625:Microscopy, Atomic Force; D036103:Nanotechnology / Q000379:methods; D010713:Phosphatidylcholines / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013109:Sphingomyelins / Q000737:chemistry
D008051:Lipid Bilayers; D008670:Metals; D010713:Phosphatidylcholines; D010743:Phospholipids; D013109:Sphingomyelins; D002784:Cholesterol; C017251:1,2-oleoylphosphatidylcholine