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Self-Assembled Hyperbranched Polymer–Gold Nanoparticle Hybrids: Understanding the Effect of Polymer Coverage on Assembly Size and SERS Performance
journal contribution
posted on 2013-01-15, 00:00 authored by Priyanka Dey, Idriss Blakey, Kristofer
J. Thurecht, Peter M. FredericksIn the past few years, remarkable progress has been made
in unveiling
novel and unique optical properties of strongly coupled plasmonic
nanostructures. However, the application of such plasmonic nanostructures
in biomedicine remains challenging because of the lack of facile and
robust assembly methods for producing stable nanostructures. Previous
attempts to achieve plasmonic nanoassemblies using molecular ligands
were limited by the lack of flexibility that could be exercised in
forming them. Here, we report the utilization of tailor-made hyperbranched
polymers (HBP) as linkers to assemble gold nanoparticles (NPs) into
nanoassemblies. The ease and flexibility in tuning the particle size
and number of branch ends of an HBP make it an ideal candidate as
a linker, as opposed to DNA, small organic molecules, and linear or
dendrimeric polymers. We report a strong correlation of polymer (HBP)
concentration with the size of the hybrid nanoassemblies and “hot-spot”
density. We have shown that such solutions of stable HBP–gold
nanoassemblies can be barcoded with various Raman tags to provide
improved surface-enhanced Raman scattering (SERS) compared to that
of nonaggregated NP systems. These Raman-barcoded hybrid nanoassemblies,
with further optimization of the NP shape, size, and hot-spot density,
may find application as diagnostic tools in nanomedicine.