title: Lipid adlayer organization mediated by a liquid overlayer.
abstract: We report on the formation of a chemically bound 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) monolayer on modified Au and silica surfaces, and changes in the organization of the interfacial lipid layer associated with immersion in aqueous solution. We have studied the interface using steady state and time resolved fluorescence spectroscopy, water contact angle and optical ellipsometry measurements, and electrochemical methods. Our data reveal that the DMPC adlayer in contact with air forms a relatively well organized interface that mediates the rotational motion of perylene. In the presence of an aqueous overlayer, perylene reorientation becomes more rapid, consistent with a reduction in the organization of the interfacial lipid adlayer. One implication of this finding is that the interfacial adlayer is less than a uniform monolayer, which is confirmed by electrochemical data. Our data underscore the importance of water in mediating the organization of interfacial lipid adlayers.
authors.affiliation: Michigan State University, Department of Chemistry, East Lansing, MI 48824, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Baumler
authors.forename: G J
authors.initials: GJ
authors.lastname: Blanchard
mesh_terms: D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry*; D055664:Electrochemical Techniques; D006046:Gold / Q000737:chemistry*; D010569:Perylene / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D010569:Perylene; D006046:Gold; D012822:Silicon Dioxide; D004134:Dimyristoylphosphatidylcholine