Rationally designed nanostructures for surface-enhanced Raman spectroscopy

Abstract

Research on surface-enhanced Raman spectroscopy (SERS) is an area of intense interest because the technique allows one to probe small collections of, and in certain cases, individual molecules using relatively straightforward spectroscopic techniques and nanostructured substrates. Researchers in this area have attempted to develop many new technological innovations including high sensitivity chemical and biological detection systems, labeling schemes for authentication and tracking purposes, and dual scanning-probe/spectroscopic techniques that simultaneously provide topographical and spectroscopic information about an underlying surface or nanostructure. However, progress has been hampered by the inability of researchers to fabricate substrates with the high sensitivity, tunability, robustness, and reproducibility necessary for truly practical and successful SERS-based systems. These limitations have been due in part to a relative lack of control over the nanoscale features of Raman substrates that are responsible for the enhancement. With the advent of nanotechnology, new approaches are being developed to overcome these issues and produce substrates with higher sensitivity, stability, and reproducibility. This tutorial review focuses on recent progress in the design and fabrication of substrates for surface-enhanced Raman spectroscopy, with an emphasis on the influence of nanotechnology.

Three-Phase Co-assembly: In Situ Incorporation of Nanoparticles into Tunable, Highly Ordered, Porous Silica Films

“…We have also successfully demonstrated that, by using selective functionalization 7 of our doped opals, local changes in the composition and optical properties of these films can be induced. This synthetic methodology can be extended to other types of nanoparticles, such as silver, 52 platinum, 53,54 and palladium, which are easily synthesized and stabilized in aqueous solutions and can lend other important properties to these hybrid 3D nanoporous materials that are beneficial for antimicrobial activity, 52 3D scaffold structures for SERS sensing, [55][56] colorimetric fluid analysis, 57 and catalytic activity. 24 We believe that the robust, large-scale, nanoparticle-doped inverse opals of uniform, tunable and accessible composition synthesized via three-phase co-assembly can find use in a whole range of applications in the fields of photonics, sensing, and catalysis.…”

A colloidoscope of colloid-based porous materials and their uses

“…Photonic effects can influence the photoinduced performance of entrapped functional components such as plasmonic nanoparticles. Indeed, efficient surface enhanced Raman scattering (SERS) substrates 253 have been made from colloidal templating due to the enhancement of plasmonic photoexcitation within the partial photonic bandgap. In this section, we focus on sensing applications that rely on structural and chemical changes in CBPM.…”

Controllable synthesis of concave cubic gold core–shell nanoparticles for plasmon-enhanced photon harvesting

“…20 Certain NPs with welldefined sharp corners and edges, where hot spots located, would generate much stronger electromagnetic field 20b,21 and exhibit larger plasmonic enhancement factors. 22 Among those intriguing nanostructures listed above, concave cubic NPs are the most interesting, because of their hot spots featuring intensified electromagnetic field as well as extraordinary high chemical activity originating from high-index facets. Despite such distinct optical and chemical properties of concave cubic NPs, there is no report yet on applying such concave nanostructures in photovoltaic devices.…”