Suitable metal nanostructures may induce surface-enhanced Raman scattering (SERS) enhancement factors (EFs) large-enough to reach single-molecule sensitivity. However, the gap hot-spot EF probability density function (PDF) has the character of a long-tail distribution, which dramatically mines the reproducibility of SERS experiments. Herein, we carry out electrodynamic calculations based on a 3D finite element method of two plasmonic nanostructures, combined with Monte Carlo simulations of the EF statistics under different external conditions. We compare the PDF produced by a homodimer of nanoparticles with that provided by a self-similar trimer. We show that the PDF is sensitive to the spatial distribution of near-field enhancement specifically supported by the nanostructure geometry. Breaking the symmetry of the plasmonic system is responsible for inducing particular modulations of the PDF tail resembling a multiple Poisson distribution. We also study the influence that molecular diffusion towards the hottest hot-spot, or selective hot-spot targeting, might have on the EF PDF. Our results quantitatively assess the possibility of designing the response of a SERS substrate so as to contain the intrinsic EF PDF variance and significantly improving, in principle, the reproducibility of SERS experiments.

Enhancement factor statistics of surface enhanced Raman scattering in multiscale heterostructures of nanoparticles / Zito, Gianluigi; Rusciano, Giulia; Sasso, Antonio. - In: THE JOURNAL OF CHEMICAL PHYSICS. - ISSN 0021-9606. - 145:5(2016), p. 054708. [10.1063/1.4960179]

Enhancement factor statistics of surface enhanced Raman scattering in multiscale heterostructures of nanoparticles

ZITO, GIANLUIGI;RUSCIANO, GIULIA;SASSO, ANTONIO
2016

Abstract

Suitable metal nanostructures may induce surface-enhanced Raman scattering (SERS) enhancement factors (EFs) large-enough to reach single-molecule sensitivity. However, the gap hot-spot EF probability density function (PDF) has the character of a long-tail distribution, which dramatically mines the reproducibility of SERS experiments. Herein, we carry out electrodynamic calculations based on a 3D finite element method of two plasmonic nanostructures, combined with Monte Carlo simulations of the EF statistics under different external conditions. We compare the PDF produced by a homodimer of nanoparticles with that provided by a self-similar trimer. We show that the PDF is sensitive to the spatial distribution of near-field enhancement specifically supported by the nanostructure geometry. Breaking the symmetry of the plasmonic system is responsible for inducing particular modulations of the PDF tail resembling a multiple Poisson distribution. We also study the influence that molecular diffusion towards the hottest hot-spot, or selective hot-spot targeting, might have on the EF PDF. Our results quantitatively assess the possibility of designing the response of a SERS substrate so as to contain the intrinsic EF PDF variance and significantly improving, in principle, the reproducibility of SERS experiments.
2016
Enhancement factor statistics of surface enhanced Raman scattering in multiscale heterostructures of nanoparticles / Zito, Gianluigi; Rusciano, Giulia; Sasso, Antonio. - In: THE JOURNAL OF CHEMICAL PHYSICS. - ISSN 0021-9606. - 145:5(2016), p. 054708. [10.1063/1.4960179]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/670063
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