0000000000303370
AUTHOR
María T. Martín-romero
Langmuir monolayers and Langmuir–Blodgett films of ferritin prepared by using a surfactant mixture of eicosylamine (EA) and methyl stearate (SME)
Abstract Magnetic Langmuir–Blodgett films of ferritin have been prepared by using the adsorption properties of a 1/4 mixed monolayer of eicosylamine (EA) and methyl stearate (SME). BAM images show that a more homogeneous distribution of ferritin at the air–water interface is achieved by using this mixture of surfactants instead of the DODA/SME mixed matrix of a previous work. Transfer of the monolayer onto different substrates allowed the preparation of multilayer LB films. Infrared and UV–Vis spectroscopies indicate that ferritin molecules are incorporated within the LB films. Furthermore, UV–Vis spectroscopy measurements reveal that the amount of ferritin incorporated into these LB film h…
Segregation of lipid in Ir-dye/DMPA mixed monolayers as strategy to fabricate 2D supramolecular nanostructures at the air–water interface
A novel pseudospherical fluorinated iridium(III) derivative, Ir-dye/PF6, [Ir(F2-ppy)2(bpy)]PF6 (F2-ppy = 2-(2,4-difluoro)phenylpyridine, bpy = 2,2′-bipyridine), has been organized by using a lipid matrix, DMPA (dimyristoyl-phosphatidic acid), in several molar ratios at the air–water interface. The molecular organization of both components and the degree of miscibility in the different mixed films have been inferred by surface techniques such as π–A isotherms, ellipsometry, reflection spectroscopy, Brewster angle microscopy (BAM), and IR spectroscopy for the LB films, additionally the results have been discussed according to the additivity rule. The equimolecular Ir-dye/DMPA mixture leads to…
Soret emission from water-soluble porphyrin thin films: effect on the electroluminescence response
The emission properties of TSPP [tetrakis(4-sulfonatophenyl) porphyrin] and TMPyP [tetrakis(4-methylpyridyl) porphyrin] in thin films, prepared both by the Langmuir–Blodgett technique and the spin-coating method, have been investigated. Surprisingly, in most of the samples analyzed, the emission spectra do not show the usual two bands typical of porphyrins (in the region 650–750 nm), and depend strongly on the excitation energy. The origin of a new emission band detected at ∼480–500 nm is discussed in terms of the nature of the porphyrin aggregates. Moreover, we demonstrate that the presence or absence of this band in the fluorescence spectrum is directly related to the generation of electr…
Molecular organization of a water-insoluble iridium(III) complex in mixed monolayers.
Abstract In this work, organized mixed monolayers containing a cationic water-insoluble iridium(III) complex, Ir-dye, [Ir(ppy)2(tmphen)]PF6, (tmphen = 3,4,7,8-tetramethyl-1,10-phenanthroline, and ppy = 2-phenylpyridine), and an anionic lipid matrix, DMPA, dimyristoyl-phosphatidic acid, with different molar proportions, were formed by the co-spreading method at the air–water interface. The presence of the dye at the interface, as well as the molecular organization of the mixed films, is deduced from surface techniques such as π – A isotherms, Brewster angle microscopy (BAM) and reflection spectroscopy. The results obtained remark the formation of an equimolar mixed film, Ir-dye/DMPA = 1:1. B…