Introductory Lecture : Surface enhanced Raman spectroscopy: new materials, concepts, characterization tools, and applications

Abstract

Surface-enhanced Raman spectroscopy (SERS) is currently experiencing a renaissance in its development driven by the remarkable discovery of single molecule SERS (SMSERS) and the explosion of interest in nanophotonics and plasmonics. Because excitation of the localized surface plasmon resonance (LSPR) of a nanostructured surface or nanoparticle lies at the heart of SERS, it is important to control all of the factors influencing the LSPR in order to maximize signal strength and ensure reproducibility. These factors include material, size, shape, interparticle spacing, and dielectric environment. All of these factors must be carefully controlled to ensure that the incident laser light maximally excites the LSPR in a reproducible manner. This article describes the use of nanosphere lithography for the fabrication of highly reproducible and robust SERS substrates for both fundamental studies and applications. Atomic layer deposition (ALD) is introduced as a novel fabrication method for dielectric spacers to study the SERS distance dependence and control the nanoscale dielectric environment. Wavelength scanned SER excitation spectroscopy (WS SERES) measurements show that enhancement factors approximately 10(8) are obtainable from NSL-fabricated surfaces and provide new insight into the electromagneticfield enhancement mechanism. Tip-enhanced Raman spectroscopy (TERS) is an extremely promising new development to improve the generality and information content of SERS. A 2D correlation analysis is applied to SMSERS data. Finally, the first in vivo SERS glucose sensing study is presented.

Performing tip‐enhanced Raman spectroscopy in liquids

“…This phenomenon has also been observed in previous TERS studies performed in air. [40,41] Additionally, strong Raman scattering was detected in the control experiment in the range of approximately 1100-1700 cm −1 with mainly two broad bands centered at approximately 1360 and 1590 cm −1 . These are the D and G band of amorphous carbon and are typical contamination bands known in TERS experiments (effect (2)).…”

Room-temperature synthesis of gold nanoparticles — Size-control by slow addition

“…Gold nanoparticles in the 1-10 nm size range have size-tuneable physico-chemical properties (1,2) that are useful in a wide variety of applications such as cancer diagnostics (3), catalysis (4), Raman and fluorescence spectroscopy (5,6), selective ionisation of biomolecules (7), and single electronics (8,9). Commercial realisation of such applications relies on economical synthesis of size-controlled nanoparticles, which requires the development of continuous-flow versions of lab-scale processes.…”

Laboratory Simulation of 11-15 μm Spectra Associated with Polycyclic Aromatic Hydrocarbon Molecules

“…These were coated in a vacuum with a thin film of silver nanoparticles to produce the conditions for SERS (see Dieringer et al 2006 for a review). Although SERS involves Raman spectroscopy, SERS spectra have been demonstrated to sample both infrared and Raman transitions (Moskovits et al 1988).…”