Optimization of Nanoparticle-Based SERS Substrates through Large-Scale Realistic Simulations

Abstract

Surface-enhanced Raman scattering (SERS) has become a widely used spectroscopic technique for chemical identification, providing unbeaten sensitivity down to the single-molecule level. The amplification of the optical near field produced by collective electron excitations —plasmons— in nanostructured metal surfaces gives rise to a dramatic increase by many orders of magnitude in the Raman scattering intensities from neighboring molecules. This effect strongly depends on the detailed geometry and composition of the plasmon-supporting metallic structures. However, the search for optimized SERS substrates has largely relied on empirical data, due in part to the complexity of the structures, whose simulation becomes prohibitively demanding. In this work, we use state-of-the-art electromagnetic computation techniques to produce predictive simulations for a wide range of nanoparticle-based SERS substrates, including realistic configurations consisting of random arrangements of hundreds of nanoparticles with various morphologies. This allows us to derive rules of thumb for the influence of particle anisotropy and substrate coverage on the obtained SERS enhancement and optimum spectral ranges of operation. Our results provide a solid background to understand and design optimized SERS substrates.

Simple, Flexible, and Ultrastable Surface Enhanced Raman Scattering Substrate Based on Plasmonic Nanopaper Decorated with Graphene Oxide

“…The typical thickness of the studied BC films is around 16 µm. As SERS enhancement strongly depends on the arrangement among noble metal nanoparticles, aiming at optimizing this enhancement that an SERS substrate made of AgNP‐decorated BC can offer following our synthesis method, we first fabricated different nanocomposites based on AgNP‐decorated BC (NC1‐ n ) exhibiting various AgNP densities and particle size distributions. These parameters can be readily tuned by changing the volume of the nanoparticles precursor involved in the synthesis (AgNO 3 ), the details on this fabrication process are provided in the Experimental Section.…”

SERS sensing of perampanel with nanostructured arrays of gold particles produced by pulsed laser ablation in water

“…Indeed, by SEM, we observe surface morphologies on the films sprayed on Si (Figure ) which differ from the colloid morphologies observed by STEM (Figure b): The isolated, small spherical NPs detected by STEM evolve into larger agglomerates consisting of mostly spherical particles observed by SEM (Figure ). Such an agglomeration process induced by spraying is actually a desirable feature when producing substrates for SERS considering that it fosters the formation of hot‐spots (Solis, Taboada, Obelleiro, Liz‐Marzán, & García de Abajo, ).…”

Gold‐patterned microarray chips for ultrasensitive surface‐enhanced Raman scattering detection of ultratrace samples

“…Metal film is one kind of commercially used SERS substrate, with good reproducibility and long‐term stability, which are easily to be fabricated into chip form, given the capability for fast and in situ detection . But the intrinsic low enhancement capability still hinders its practical application, like Klarite and Q‐SERS substrates, although it could be further increased by building some nanostructures on the surface of the film . A practical detection application requires the SERS substrate not only has high enhancement, long‐term stability, and good reproducibility but also satisfies fast and easily‐operated analytical method with only trace samples.…”