2 research outputs found
Plasmonic Nanoantenna Arrays for Surface-Enhanced Raman Spectroscopy of Lipid Molecules Embedded in a Bilayer Membrane
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
Bending Gold Nanorods with Light
V-shaped
gold nanoantennas are the functional components of plasmonic
metasurfaces, which are capable of manipulating light in unprecedented
ways. Designing a metasurface requires the custom arrangement of individual
antennas with controlled shape and orientation. Here, we show how
highly crystalline gold nanorods in solution can be bent, one-by-one,
into a V-shaped geometry and printed to the surface of a solid support
through a combination of plasmonic heating and optical force. Significantly,
we demonstrate that both the bending angle and the orientation of
each rod-antenna can be adjusted independent from each other by tuning
the laser intensity and polarization. This approach is applicable
for the patterning of V-shaped plasmonic antennas on almost any substrate,
which holds great potential for the fabrication of ultrathin optical
components and devices