title: Plasmonic nanoantenna arrays for surface-enhanced Raman spectroscopy of lipid molecules embedded in a bilayer membrane.
abstract: We demonstrate a strategy for surface-enhanced Raman spectroscopy (SERS) of supported lipid membranes with arrays of plasmonic nanoantennas. Colloidal lithography refined with plasma etching is used to synthesize arrays of triangular shaped gold nanoparticles. Reducing the separation distance between the triangle tips leads to plasmonic coupling and to a strong enhancement of the electromagnetic field in the nanotriangle gap. As a result, the Raman scattering intensity of molecules that are located at this plasmonic "hot-spot" can be increased by several orders of magnitude. The nanoantenna array is then embedded with a supported phospholipid membrane which is fluid at room temperature and spans the antenna gap. This configuration offers the advantage that molecules that are mobile within the bilayer membrane can enter the "hot-spot" region via diffusion and can therefore be measured by SERS without static entrapment or adsorption of the molecules to the antenna itself.
authors.affiliation: Photonics and Optoelectronics Group, Department of Physics and Center for NanoScience (CeNS), Ludwig Maximilian University München , Amalienstrasse 54, Munich 80799, Germany.
authors.forename: Paul
authors.initials: P
authors.lastname: Kühler
authors.forename: Max
authors.initials: M
authors.lastname: Weber
authors.forename: Theobald
authors.initials: T
authors.lastname: Lohmüller
mesh_terms: D006046:Gold / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry; D008566:Membranes / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D020349:Surface Plasmon Resonance
chemical_list: D008051:Lipid Bilayers; D008055:Lipids; D006046:Gold