Self-assembled monolayers (SAMs) comprised of a mixture of a cholesterol functionalized thiol derivative and a short chain ethyleneoxythiol derivative have been used to attach phospholipid bilayers to gold surfaces. The cholesterol derivatives serve as “anchoring units” and are inserted into the lower leaflet of the attached bilayer. The short chain ethyleneoxy derivatives are present to promote a disordered hydrophilic region beneath the bilayer. The bilayers were formed by incubation of the SAMs with small unilamellar vesicles. On single component hydrophobic surfaces a single lipid layer was adsorbed, while on mixed SAMs containing the cholesterol anchoring units, and single component hydrophilic surfaces, a lipid bilayer was adsorbed. The kinetics of bilayer formation was followed using surface plasmon resonance spectroscopy, and showed dramatic differences depending on the SAM composition.

The anchoring of the nematic liquid crystal (LC) 4′-n-octyl-4-cyanobiphenyl (8CB) at derivatized self-assembled monolayer (SAM) surfaces has been investigated using surface plasmon resonance (SPR) microscopy. Surfaces having distinct areas (patterns) covered by different ω-functionalized groups, one (-CF3) promoting homeotropic anchoring of the nematic director and the other (-OH) planar anchoring, were fabricated from photopatterned SAMs. Our results show that SPR microscopy, which is sensitive to the alignment on the mesoscale (i.e., within 300 nm of the interface) can be used to spatially resolve the anchoring of adsorbed LC films, with a lateral resolution on the order of a few micrometers, as a function of temperature. In addition, we observe surface melting of the crystalline phase at the SAM boundary by both homeotropic and planar aligned melts.

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