Applications of Surface-Enhanced Raman Scattering in Biochemical and Medical Analysis

Abstract

In this mini-review, we briefly describe certain recently developed applications of the surface-enhanced Raman spectroscopy (SERS) for determining various biochemically (especially medically) important species from ones as simple as hydrogen cations to those as complex as specific DNA fragments. We present a SERS analysis of species whose characterization is important to our understanding of various mechanisms in the human body and to show its potential as an alternative for methods routinely used in diagnostics and clinics. Furthermore, we explain how such SERS-based sensors operate and point out future prospects in this field.

Rapid Determination of the ‘Legal Highs’ 4-MMC and 4-MEC by Spectroelectrochemistry: Simultaneous Cyclic Voltammetry and In Situ Surface-Enhanced Raman Spectroscopy

“…In comparison, these low concentrations may not be detected using non-SERS Raman due to a decrease in sensitivity, and therefore a loss in peak resolution compared to SERS. The possibility to identify and quantify low concentrations of the target drugs gives the technique a potential use for testing both seizure samples and biological matrices [ 59 ] or even in instances where the fluorescence overwhelms the Raman signals [ 60 ]. Furthermore, in situ SERS substrate activation provides some benefits to overcoming a possible time-dependent decrease of the surface and plasmonic properties, which could affect the reproducibility and reliability of the measurements [ 29 ].…”

Stationary, Continuous, and Sequential Surface‐Enhanced Raman Scattering Sensing Based on the Nanoscale and Microscale Polymer‐Metal Composite Sensor Particles through Microfluidics: A Review

“…[19,57] Due to their working ability in a diverse environment, SERS can be broadly applicable for characterizations in the field of chemistry, materials, and life science. [11,[58][59][60] The excitation source in the SERS experiments is intense, usually a laser of a defined wavelength such as 532 nm. [61] Excitation sources of various wavelength regions from the UV to IR range can be used depending on the types of substrate and SERS instruments.…”

Attachment of Single-Stranded DNA to Certain SERS-Active Gold and Silver Substrates: Selected Practical Tips

“…It can be deduced that, for the samples prepared using a freezing step, the degree of aggregation is significantly larger. Since the aggregation of plasmonic nanoparticles significantly increases their SERS activity (especially large SERS enhancements are observed for molecules in the narrow slits between the plasmonic nanoparticles, known as "hot spots" [20,21]), a certain agglomeration of the gold nanoparticles after the freezing step is probably also a cause of the larger SERS activity of such samples. During freezing, water crystals form, which cause a concentration of the solution (meaning a local concentration of the gold nanoparticles and DNA).…”

“…molecules in the narrow slits between the plasmonic nanoparticles, known as "hot spot [20,21]), a certain agglomeration of the gold nanoparticles after the freezing step probably also a cause of the larger SERS activity of such samples. During freezing, wat crystals form, which cause a concentration of the solution (meaning a local concentrati of the gold nanoparticles and DNA).…”

“…The SERS phenomenon is explained as a result of a synergistic cooperation of two mechanisms: a local enhancement of the intensity of the electric field, which is a consequence of the excitation of the localized surface plasmons, and an increase in the efficiency of the generation of Raman scattering due to chemical interactions with the SERS substrate, in an effect similar to standard resonance Raman scattering [20,21]. Important characteristic features of the enhancement of the SERS spectrum are a sharp decrease with increasing distance from the SERS substrate, and in the case of an agglomeration or aggregation of plasmonic SERS-active nanostructures, a very large increase in the SERS activity of the material (a very large field enhancement is observed in the narrow slits between the plasmonic nanograins, known as "hot spots", and the formation of such structures significantly increases the SERS activity of the material) [20,21]. SERS is one of the most sensitive analytical tools, and in some cases, it is possible to observe a quality SERS spectrum of even a single molecule [22,23].…”