  Spectra of octadecylamine (ODA) Langmuir monolayers and egg
phosphatidylcholine (PC)/ODA-mixed monolayers at the air-water interface have
been acquired. The organization of the monolayers has been characterized by
surface pressure-area isotherms. Application of polarized optical microscopy
provides further insight in the domain structures and interactions of the film
components. Surface-enhanced Raman scattering (SERS) data indicate that
enhancement in Raman spectra can be obtained by strong interaction between
headgroups of the surfactants and silver particles in subphase. By mixing ODA
with phospholipid molecules and spreading the mixture at the air-water
interface, we acquired vibrational information of phospholipid molecules with
surfactant-aided SERS effect.
