|Title||Toward hyperuniform disordered plasmonic nanostructures for reproducible surface-enhanced Raman spectroscopy|
|Publication Type||Articolo su Rivista peer-reviewed|
|Year of Publication||2015|
|Authors||De Rosa, C., Auriemma F., Diletto C., Di Girolamo R., Malafronte A., Morvillo P., Zito G., Rusciano G., Pesce G., and Sasso A.|
|Journal||Physical Chemistry Chemical Physics|
We report on the self-assembling of clusters of gold-nanoparticles (Au-NPs) directed by the phase separation of poly(styrene)-b-poly(methylmethacrylate) (PS-b-PMMA) block-copolymer (BCP) on indium tin oxide coated glass, which induces the onset of vertical lamellar domains. After thermal evaporation of gold on BCP, Au-NPs of 4 nm are selectively included into PS-nanodomains by thermal annealing, and then clustered with large density of hot spots (> 104 μm2) in a random two-dimensional pattern. The resulting nanostructure exhibits near-hyperuniform long-range correlations. The consequent large degree of homogeneity of this isotropic plasmonic pattern gives rise to a highly reproducible Surface-Enhanced Raman Scattering (SERS) enhancement factor over the centimeter scale (std. dev. ∼ 10% over 0.25 cm2). We also discuss the application of a static electric field for modulating the BCP host morphology. The electric field induces an alignment of Au-NP clusters into ordered linear chains, exhibiting a stronger SERS activity, but reduced SERS spatial reproducibility. © 2015 the Owner Societies.
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