Bio-imaging, detection and analysis by using nanostructures as SERS substrates

Abstract

Surface-enhanced Raman scattering (SERS) is a phenomenon that occurs on nanoscale-roughed metallic surface. The magnitude of the Raman scattering signal can be greatly enhanced when the scatterer is placed in the very close vicinity of the surface, which enables this phenomenon to be a highly sensitive analytical technique. SERS inherits the general strongpoint of conventional Raman spectroscopy and overcomes the inherently small cross section problem of a Raman scattering. It is a sensitive and nondestructive spectroscopic method for biological samples, and can be exploited either for the delivery of molecular structural information or for the detection of trace levels of analytes. Therefore, SERS has long been regarded as a powerful tool in biomedical research. Metallic nanostructure plays a key role in all the biomedical applications of SERS because the enhanced Raman signal can only be obtained on the surface of a finely divided substrate. This review focuses on progress made in the use of SERS as an analytical technique in bio-imaging, analysis and detection. Recent progress in the fabrication of SERS active nanostructures is also highlighted.

Identification of Individual Exosome-Like Vesicles by Surface Enhanced Raman Spectroscopy

“…This originates from variability within the ELV population but potentially also from the (random) adsorption of AuNP on the vesicle surface and non-uniformity in hot spot generation. [46] In future research, therefore, it will be of interest to investigate other ways of functionalizing vesicles with AuNP with the aim to make the SERS spectra more uniform among vesicles of the same origin. This would allow to detect more subtle differences in molecular compositions and obtain more reliable molecular information from each individual vesicle.…”

Time-Resolved Study of the Surface-Enhanced Raman Scattering Effect of Silver Nanoparticles Generated in Voltammetry Experiments.

“…1 Particularly, AgNPs exhibit electrochemical, 2 catalytic, 3 antimicrobial 4 and optical 5 properties that make them especially interesting in electronic, catalysis and sensors fields. [6][7][8][9][10] These properties, as in other kind of metal NPs, are related with their sizes and shapes. Therefore, it is very important to develop synthetic routes to control the shape and size of NPs.…”

Highly Sensitive Surface-Enhanced Raman Scattering Sensing of Heparin Based on Antiaggregation of Functionalized Silver Nanoparticles

“…20,21 Its two well-known primary theoretical mechanism models are long-range electromagnetic (EM) enhancement and short-range chemical enhancement (CE). EM enhancement emphasizes the effect of the nanosubstrate providing the long-range electromagnetic fields, which determined by the nanosubstrate's inherent properties (material type, shape, and size).…”

“…And CE is achieved by changing the scattering cross section of the analytes attached on a metal surface, thus depends on the chemical features of the analytes themselves. 21,22 It is acknowledged that EM enhancements always considered as the major contribution to the SERS phenomenon. 23,24 Since its discovery in the late 1970s, SERS has been applied to many analyses.…”