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Nano Research & Applications
ISSN 2471-9838 Advanced Nano 2017
Notes:
Page 48
September 11-12, 2017 Amsterdam, Netherlands
20th International Conference on
Advanced Nanotechnology
Multiple hot spots 3D nanostructures: ultrasensitive
substrates for surface-enhanced Raman spectroscopy
Andrea Cerea1, 2, Manohar Chirumamilla1, 3, Anisha Gopalakrishnan3 ,
and Andrea Toma1
1Istituto Italiano di Tecnologia, Italy
2University of Genova, Italy
3University of Aalborg, Denmark
Over the last few years, great efforts have been made in
order to increase the performances of sensors down
to ultralow concentrations (10-15 м) of analyte molecules,
with exceptional consequences in the fields of photonics,
nonlinear optics and imaging. Within this context, Surface
Enhanced Raman Spectroscopy (SERS) provides label-
free detection of analytes down to the single-molecule
level with high specificity and sensitivity. Conventional and
cost-effective approaches exploit bottom-up techniques
for the realization of large SERS substrates with a random
and high density distribution of active sites, also called
hot spots. Complementary strategies employ top-down
methods, which allow the realization of high uniformity
SERSactive surfaceswith precise control over the position,
size and shape of the hot spots. By taking advantage of
the interaction between analyte molecules and enhanced
optical near-fields in the vicinity of resonantly excited
plasmonic nanostructures, plasmon-based devices
represent a good candidate for SERS. Here, we present the
realization and experimental characterization of 3D multi-
branched nanostructures as a viable strategy for intense
electric hot-spot generation and SERS applications. Our
structures, arranged in isolated or coupled configuration,
support intense localized surface plasmon resonances
(LSPRs) with an associated giant electromagnetic (EM)
field confinement and enhancement factors up to 108.
Further developments of our 3D nanostructures have
led to the realization of bimetallic Au/Ag nanostructures
with a multi-branched geometry. This novel architecture
integrates the advantages of extremely high EM field
enhancement, owing to the plasmonic properties of Ag,
with the excellent biocompatibility and chemical stability
provided by the single metal Au analogue. Moreover,
the present layout can support large hot spots densities
comparable to those obtained with bottom-up techniques,
although with greater reproducibility and precise control
over the spatial location of the active areas.
Biography
Andrea Cerea is currently pursuing his PhD at University of Genoa and the
Italian Institute of Technology. He is working in the Plasmon Nanotechnology
Group, with focus on the development of photonic metamaterials for
electromagnetic field manipulation.
Andrea Cerea et al., Nano Res Appl 2017, 3:3
DOI: 10.21767/2471-9838-C1-002