Surface enhanced Raman spectroscopy (SERS) is a powerful vibrational technique that allows for highly sensitive structural detection of low concentration analytes through the amplification electromagnetic fields generated by excitation localized surface plasmons. SERS has progressed from studies model systems on roughened electrodes to sophisticated studies, such as single molecule spectroscopy. We summarize current state knowledge concerning mechanism and new substrate materials. highlight...

Understanding the detailed relationship between nanoparticle structure and activity remains a significant challenge for field of surface-enhanced Raman spectroscopy. To this end, structural optical properties individual plasmonic nanoantennas comprised Au assemblies that are coated with organic reporter molecules encapsulated by SiO(2) shell have been determined using correlated transmission electron microscopy (TEM), dark-field Rayleigh scattering microscopy, (SERS) finite element method...

In this perspective we discuss the roles of hot spots in surface-enhanced Raman spectroscopy (SERS). After giving background and defining spot, evaluate a variety SERS substrates which often contain spots. We compare differentiating properties each substrate. then provide thorough analysis spot contribution to observed signal both ensemble-averaged single-molecule conditions. also enumerate rules for determining enhancement factor (EF) clarify use common metric. Finally, present...

Determining the existence of any direct spectral relationship between far-field scattering properties and near-field Raman-enhancing surface-enhanced Raman spectroscopy (SERS) substrates has been a challenging task with only few significant results to date. Here, we prove that hot spot dominated systems show little dependence on because differences near- localized surface plasmon resonance (LSPR) effects as well excitation new modes via emitter. We directly probe light interactions using...

This article provides a review of our recent studies single metal nanoparticles and nanoparticle clusters aimed at correlating the structural plasmonic properties same entity. The correlation between structure optical arising from localized surface plasmon resonance (LSPR) on various samples is described. Nanoparticles different materials (Ag Au) shapes (spheres, cubes, triangles) are considered. Experiments were carried out using transmission electron microscopy (TEM), dark-field...

This perspective presents recent developments in the application of surface-enhanced Raman spectroscopy (SERS) to biosensing, with a focus on vivo diagnostics. We describe concepts and methodologies developed date target analytes that can be detected. also discuss how SERS has evolved from "point-and-shoot" stand-alone technique an analytical chemistry laboratory integrated quantitative tool for multimodal imaging Finally, we offer guide future context clinical

Interest in nanotechnology is driven by the unique and novel properties of nanoscale materials such as strong interaction metal particles with light, caused localized surface plasmon resonances (LSPRs). In this perspective article we review discuss prominent advantages advances single particle studies plasmonic nanostructures. Common techniques recent improvements spatial spectral resolution will first be outlined, covering both far-field near-field phenomena. Then, new insight information...

We present a high-resolution distance dependence study of surface-enhanced Raman scattering (SERS) enabled by atomic layer deposition (ALD) at 55 and 100 °C. ALD is used to deposit monolayers Al2O3 on bare silver film over nanospheres (AgFONs) AgFONs functionalized with self-assembled monolayers. Operando SERS measure the intensities Al–CH3 C–H stretches from trimethylaluminum (TMA) as function AgFON surface. This clearly demonstrates that substrates displays both short- long-range nanometer...

Surface-enhanced Raman spectroscopy (SERS) and femtosecond stimulated (FSRS) have revolutionized the field. SERS provides spectroscopic detection of single molecules, FSRS enables acquisition spectra on ultrafast time scale molecular motion. Here, we present first successful combination these two techniques, demonstrating surface-enhanced (SE-FSRS) using gold nanoantennas with embedded reporter molecules. Using a picosecond probe pulse, time- ensemble-averaged enhancement factor is estimated...

We describe the fabrication of optimized plasmonic substrates in form immobilized nanorod assemblies (INRA) for surface-enhanced Raman spectroscopy (SERS). Included are high-resolution scanning electron micrograph (SEM) images surface structures, along with a mechanistic description their growth. It is shown that, by varying size support microspheres, plasmon resonance tuned between 330 and 1840 nm. Notably, there predicted optimal microsphere sizes each commonly used SERS laser wavelengths...

Surface-enhanced Raman spectroscopy (SERS) is a sensitive, chemically specific, and short-time response probing method with significant potential in biomedical sensing. This paper reports the integration of SERS microneedle arrays as minimally invasive platform for chemical sensing, particular view toward sensing interstitial fluid (ISF). Microneedle were fabricated from commercial polymeric adhesive coated plasmonically active gold nanorods that functionalized pH-sensitive molecule...

This paper demonstrates the direct sensing of glucose at physiologically relevant concentrations with surface-enhanced Raman spectroscopy (SERS) on gold film-over-nanosphere (AuFON) substrates functionalized bisboronic acid receptors. The combination selectivity in receptor and spectral resolution SERS data allow sensors to resolve high backgrounds fructose and, multivariate statistical analysis, detect accurately 1–10 mM range. Computational modeling supports assignments normal modes...

We provide conclusive proof of single molecule (SM) detection by surface-enhanced Raman spectroscopy (SERS) for discrete Ag triangular nanopyramids prepared via nanosphere lithography (NSL). While the observation SMSERS has been well-demonstrated using various chemically synthesized nanoparticle substrates, they have a high degree polydispersity in shape, size, and aggregation state resulting an interest to develop more reproducible uniform nanoparticles. Here triangular-based were...

Here, an investigation into the optical response of truncated and nontruncated Ag triangular nanoprisms is presented. Single particle darkfield microspectroscopy transmission electron microscopy (TEM) are performed to obtain overview relationship between plasmonic properties nanoparticle structure. A general framework built describe (resonant wavelength λmax full width at half maximum (fwhm)) triangle in a size regime (60–140 nm edge length) that has not been investigated previously this...

Surface-enhanced Raman spectroscopy (SERS) is an ideal tool for analyzing dyes on historical textiles because it requires very little sample compared to other available analytical methods and analysis can be done directly the fiber. This paper reports first systematic study of use citrate-reduced silver colloidal pastes direct, extractionless, non-hydrolysis detection wool, silk, cotton, flax fibers. type provides greater insight into optimal conditions required accurate in samples. In this...

Noble metal nanoparticle clusters underlie a variety of plasmonic devices and measurements including surface-enhanced Raman spectroscopy (SERS). Because the strong dependence properties on cluster aggregation state, elimination non-SERS-active structures refinement population are critical to realizing uniform reproducible for nanoantenna applications such as SERS-based sensors. In this Letter, we report centrifugal sorting technique gold core/silica shell nanoparticles that host SERS...

Decanethiol-passivated silver nanocrystals are shown, by small-angle X-ray diffraction, to organize into hexagonal close packed or face centered cubic (fcc) structures depending on the substrate temperature. When passivated dodecanethiols, fcc and body lattices as well disordered arrangements observed. The different crystalline phases correspond thermodynamic equilibrium states. passivant chain length is shown control interactions between consequently superlattice structure.

Because of the sharp distance dependence surface-enhanced Raman spectroscopy (SERS), analyte molecules that do not exhibit strong affinity for Au/Ag often elude detection. New methods integrating such analytes with SERS substrates are required to circumvent this limitation and expand sensitivity new applications. We communicate here a solution-phase, capture agent-free method aggregating Au nanospheres in presence five neurotransmitters (dopamine, epinephrine, norepinephrine, serotonin,...

This work demonstrates for the first time capability of measuring surface vibrational spectra adsorbates during atomic layer deposition (ALD) reactions using operando surface-enhanced Raman spectroscopy (SERS). We use SERS to study alumina ALD growth at 55 °C on bare silver film-over nanosphere (AgFON) substrates as well AgFONs functionalized with thiol self-assembled monolayers (SAMs). On AgFONs, we observe Al–C stretches, symmetric C–H and asymmetric stretches trimethylaluminum (TMA) dose...

The optical properties of silver nanocrystal arrays are investigated using spectroscopic ellipsometry in combination with polarized reflection measurements. Analysis the and reflectometry spectra terms “thin island film” theory enables a transparent identification contribution collective effects to response. Negligible image charge imply that only dipole contributions have be considered. interactions between hexagonally ordered nanocrystals give rise an effective modification spherical...

Four decades on, surface-enhanced Raman spectroscopy (SERS) continues to be a vibrant field of research that is growing (approximately) exponentially in scope and applicability while pushing at the ultimate limits sensitivity, spatial resolution, time resolution. This introductory paper discusses some aspects related all four themes for this Faraday Discussion. First, wavelength-scanned SERS excitation (WS-SERES) single nanosphere oligomers (<italic>viz.</italic>, dimers, trimers,...