title: Surface enhanced Raman spectroscopy of self-assembled layers of lipid molecules on nanostructured Au and Ag substrates.
abstract: In this work surface enhanced Raman spectroscopy (SERS) has been used for the investigation of the self-assembled layers of lipid molecules (SALLMs) deposited on the nanostructured Au and Ag surfaces. The SALLMs were prepared from one part of 1,2-dioleoyl-sn-glycero-3-phospho-l-serine (DOPS) and four parts of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) lipids. The synthesis of Au and Ag SERS substrates was based on the direct gold and silver ions reduction onto HF etched silicon wafers. Au SERS substrates were not suitable for the formation of SALLMs because of the inappropriate contact angle of surface. It was found that the formation of the SALLM does not take place on Au SERS substrate. However, it has been shown that the modification of Au SERS substrate with 1-dodecanothiol layer allows building the SALLM on its surface. In the case of Ag SERS substrate, the SALLM was deposited directly on its surface. The SERS spectra of the SALLMs were recorded in the CH stretching (2800-3000cm-1) and the fingerprint (<1.800cm-1) regions. It has been demonstrated that the SERS spectra of the SALLM recorded on Au substrate differs from that one recorded on Ag SERS substrate. These spectral differences were found to be determined by the different interaction mechanisms of the lipid molecules with nanostructured surfaces.
authors.affiliation: Research Centre for Microsystems and Nanotechnology, Kaunas University of Technology, Studentu 65, LT-51369, Kaunas, Lithuania.
authors.forename: Nora
authors.initials: N
authors.lastname: Slekiene
authors.affiliation: Research Centre for Microsystems and Nanotechnology, Kaunas University of Technology, Studentu 65, LT-51369, Kaunas, Lithuania.
authors.forename: Lina
authors.initials: L
authors.lastname: Ramanauskaite
authors.affiliation: Research Centre for Microsystems and Nanotechnology, Kaunas University of Technology, Studentu 65, LT-51369, Kaunas, Lithuania. Electronic address: vsnitka@ktu.lt.
authors.forename: Valentinas
authors.initials: V
authors.lastname: Snitka
mesh_terms: D006046:Gold / Q000737:chemistry*; D008051:Lipid Bilayers / Q000138:chemical synthesis / Q000737:chemistry*; D008055:Lipids / Q000138:chemical synthesis / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D015394:Molecular Structure; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D013499:Surface Properties
chemical_list: D008051:Lipid Bilayers; D008055:Lipids; D012834:Silver; D006046:Gold
keywords: Lipid membranes; Nanostructured surfaces; Self-assembled layers of lipid molecules; Surface enhanced Raman spectroscopy