Photophysical Study of Pyrene-Labeled Phospholipids at the Gas/Water Interface

Abstract

The surface monolayer technique was used to study the properties of biomembrane-like systems. The technique was used in combination with surface fluorescence measurements of fluorescent probes incorporated into a phospholipid matrix. Two types of fluorescent probe containing the chromophore pyrene bound to the hydrocarbon tail and the amino group of the phospholipid, respectively, were used. The fluorescent properties of the molecules were studied both in solution and in monolayers. On the basis of the results, fluorescence changes in the molecules upon compression of the monolayers studied arise from increased compactness in the phospholipid, which decreases permeation of atmospheric oxygen and hinders orientation changes in the chromophore at the interface.

Single-Step Dispersion of Functionalities on a Silica Surface

“…As a matter of fact, the three main bands at 380, 400, and 420 nm are centered at the same wavelengths as those of the parent molecule N -(phenyl)-1-pyrenesulfonamide in toluene solution. Furthermore, molecules bearing a similar pyrene sulfonamide chromophore displayed emission bands close to these maxima. – Using the terminology of Thomas et al also taken up by González-Benito et al, the bands at 380 and 400 nm are referred to as band I and band V, respectively. In the silica materials, bands I and V were used as an index of the polarity by analogy with the well-known polarity py-scale in solutions .…”

“…Furthermore, molecules bearing a similar pyrene sulfonamide chromophore displayed emission bands close to these maxima. [65][66][67] Using the terminology of Thomas et al 68 also taken up by Gonza ´lez-Benito et al, 65 the bands at 380 and 400 nm are referred to as band I and band V, respectively. In the silica materials, bands I and V were used as an index of the polarity 65 by analogy with the well-known polarity py-scale in solutions.…”

Surface Pressure−Area Isotherms and Fluorescent Behavior of a ω-6-(N-Methyl-N-alkylamine) Naphthoylalkanoic Acid (MANA)

“…The potential applications of Langmuir monolayers and Langmuir−Blodgett films (LB) in various physical, chemical and biological fields − have promoted studies on a wide variety of monolayer-forming materials. In contrast with the well-known behavior of traditional amphiphiles used to form monolayers at the air−water interface, very little research on aromatic analogues of aliphatic compounds has so far been conducted. − Some such materials possess interesting optical properties that allow their use in biosensor technology and in nonlinear optical devices 3,4 and allow one to study various biological environments. − For instance, many membrane fluorescent probes are sensitive to bilayer polarity and can be used as fluorescent probes when they are inserted in a film. Then, these molecules can be useful tools to obtain information about different properties of membranes such as the phase state, fluidity, polarity, and microviscosity.…”

“…In contrast with the well-known behavior of traditional amphiphiles used to form monolayers at the air-water interface, very little research on aromatic analogues of aliphatic compounds has so far been conducted. [5][6][7][8][9][10][11][12][13][14][15][16][17][18] Some such materials possess interesting optical properties that allow their use in biosensor technology and in nonlinear optical devices 3,4 and allow one to study various biological environments. [19][20][21][22][23] For instance, many membrane fluorescent probes are sensitive to bilayer polarity and can be used as fluorescent probes when they are inserted in a film.…”