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Download fileMechanically Self-Assembled, Three-Dimensional Graphene–Gold Hybrid Nanostructures for Advanced Nanoplasmonic Sensors
journal contribution
posted on 2015-11-11, 00:00 authored by Juyoung Leem, Michael Cai Wang, Pilgyu Kang, SungWoo NamHybrid
structures of graphene and metal nanoparticles (NPs) have been actively
investigated as higher quality surface enhanced Raman spectroscopy
(SERS) substrates. Compared with SERS substrates, which only contain
metal NPs, the additional graphene layer provides structural, chemical,
and optical advantages. However, the two-dimensional (2D) nature of
graphene limits the fabrication of the hybrid structure of graphene
and NPs to 2D. Introducing three-dimensionality to the hybrid structure
would allow higher detection sensitivity of target analytes by utilizing
the three-dimensional (3D) focal volume. Here, we report a mechanical
self-assembly strategy to enable a new class of 3D crumpled graphene–gold
(Au) NPs hybrid nanoplasmonic structures for SERS applications. We
achieve a 3D crumpled graphene–Au NPs hybrid structure by the
delamination and buckling of graphene on a thermally activated, shrinking
polymer substrate. We also show the precise control and optimization
of the size and spacing of integrated Au NPs on crumpled graphene
and demonstrate the optimized NPs’ size and spacing for higher
SERS enhancement. The 3D crumpled graphene–Au NPs exhibits
at least 1 order of magnitude higher SERS detection sensitivity than
that of conventional, flat graphene–Au NPs. The hybrid structure
is further adapted to arbitrary curvilinear structures for advanced,
in situ, nonconventional, nanoplasmonic sensing applications. We believe
that our approach shows a promising material platform for universally
adaptable SERS substrate with high sensitivity.