Surface-enhanced Raman scattering: overview of a versatile technique used in electrochemistry and nanoscience (original) (raw)

A Review on Surface-Enhanced Raman Scattering

Biosensors, 2019

Surface-enhanced Raman scattering (SERS) has become a powerful tool in chemical, material and life sciences, owing to its intrinsic features (i.e., fingerprint recognition capabilities and high sensitivity) and to the technological advancements that have lowered the cost of the instruments and improved their sensitivity and user-friendliness. We provide an overview of the most significant aspects of SERS. First, the phenomena at the basis of the SERS amplification are described. Then, the measurement of the enhancement and the key factors that determine it (the materials, the hot spots, and the analyte-surface distance) are discussed. A section is dedicated to the analysis of the relevant factors for the choice of the excitation wavelength in a SERS experiment. Several types of substrates and fabrication methods are illustrated, along with some examples of the coupling of SERS with separation and capturing techniques. Finally, a representative selection of applications in the biomed...

Surface-Enhanced Raman Scattering: Introduction and Applications

Recent Advances in Nanophotonics - Fundamentals and Applications

Scattering of light by molecules can be elastic, Rayleigh scattering, or inelastic, Raman scattering. In the elastic scattering, the photon’s energy and the state of the molecule after the scattering events are unchanged. Hence, Rayleigh scattered light does not contain much information on the structure of molecular states. In inelastic scattering, the frequency of monochromatic light changes upon interaction with the vibrational states, or modes, of a molecule. With the advancement in the laser sources, better and compact spectrometers, detectors, and optics Raman spectroscopy have developed as a highly sensitive technique to probe structural details of a complex molecular structure. However, the low scattering cross section (10−31) of Raman scattering has limited the applications of the conventional Raman spectroscopy. With the discovery of surface-enhanced Raman scattering (SERS) in 1973 by Martin Fleischmann, the interest of the research community in Raman spectroscopy as an ana...

Current understanding of the mechanism of surface enhanced raman scattering

Journal of Electroanalytical Chemistry

On Cu, Ag, Au, and Li, geometrically defined surface optical resonances are a major contributor to surface enhanced Raman scattering (SERS). This explains the incident photon energy dependence, the variation among these metals from metal to metal, the extension of the enhancement to molecules removed from the surface, and the sensitivity that SERS demonstrates toward surface roughness on the 5 to 200 nm scale. Additional features of the enhancement, such as short range effects in the first monolayer of the adsorbate, molecular specificity, and the demonstration of enhanced scattering for molecules on Ni and Pt are associated with active sites. These active sites, which may be adatoms, and which in some cases involve complex formation, lead to electronic resonance which is similar to the normal resonant Raman effect but which requires the association between the metal and the molecule.

Nature of the Active Site in Surface-Enhanced Raman Scattering

Physical Review Letters, 1983

Experiments involving competitive and cooperative adsorption of pyridine, Cl, SCN, and Tl, and voltage induced resonance shifting show that the largest surface-enhanced Raman scattering intensity comes from complexes of these species adsorbed on defects which cover less than 3%%un of the Ag surface. The resonance is attributed to charge transfer excitation from Ag to pyridine and from SCN to Ag which is communicated to all vibrations of the complex.

Surface-Enhanced Raman Scattering as an Emerging Characterization and Detection Technique

Journal of Nanotechnology, 2012

While surface-enhanced Raman spectroscopy (SERS) has been attracting a continuously increasing interest of scientific community since its discovery, it has enjoyed a particularly rapid growth in the last decade. Most notable recent advances in SERS include novel technological approaches to SERS substrates and innovative applications of SERS in medicine and molecular biology. While a number of excellent reviews devoted to SERS appeared in the literature over the last two decades, we will focus this paper more specifically on several promising trends that have been highlighted less frequently. In particular, we will briefly overview strategies in designing and fabricating SERS substrates using deterministic patterning and then cover most recent biological applications of SERS.