High-resolution near-field scanning optical microscopy (NSOM) fluorescence
and topographic images of L-alpha-dipalmitoylphosphatidylcholine (DPPC) mon
olayers doped with a fluorescent dye are presented, DPPC monolayers are dep
osited onto mica substrates from the air-water interface at several surface
pressures using the Langmuir-Blodgett technique, Sub-diffraction limit pha
se domain structures are observed in both fluorescence and topographic NSOM
images of the lipid films. The morphology of the resulting monolayers depe
nds strongly on the surface pressure and composition of the subphase used i
n the film transfer, Mechanisms for lipid domain formation and growth are d
iscussed.