F. Gaboriaud et al., Organization and structural properties of langmuir films composed of conjugated polydiacetylene and phospholipids, LANGMUIR, 17(12), 2001, pp. 3651-3657
Molecular assemblies containing phospholipids and conjugated polydiacetylen
e lipids exhibit unique biockromatic properties and have attracted increasi
ng interest in recent years as potential bio- and chemosensors. We present
a detailed study of the properties of mixed films formed at the air-water i
nterface, which consist of phospholipid molecules and diacetylene lipids. T
he organization of the films has been characterized by surface pressure-are
a isotherms. Application of atomic force microscopy, polarized optical micr
oscopy, and W-vis spectroscopy provides further insight into the structures
and interactions of the film components. The data indicate that the two co
nstituents in the film are miscible at low surface pressure, while segregat
ion of phospholipid and polymer domains occurs at higher surface pressures.
The distribution and interactions between the diacetylene and phospholipid
domains additionally depends on the molar fraction of phospholipid in the
film. Characterization of the structural properties of the polydiacetylene
domains in the films points to a formation of organized trilayer and multil
ayer phases at high surface pressures and high diacetylene concentrations.