What is SERS nanotechnology?
Surface-enhanced Raman spectroscopy or surface-enhanced Raman scattering (SERS) is a surface-sensitive technique that enhances Raman scattering by molecules adsorbed on rough metal surfaces or by nanostructures such as plasmonic-magnetic silica nanotubes.
What is the role of metal nanoparticles in SERS?
SERS substrates that typically composed of metal nanostructures can enhance the Raman signal level up to several orders of magnitude, making it a powerful analytical tool in chemical and biomedical applications.
What are SERS substrates?
What is a SERS substrate? A Silmeco SERS substrate, called a SERStrate, is essentially a silicon wafer coated with a metal like gold or silver (or a custom metal of choice). The silicon wafer is made up of a special structure – ag/au coated nano-pillars – which facilitates molecular sensing (Raman scattering).
Why gold and silver are used in SERS?
They are easily oxidised and lose their SERS performances in a few weeks. However, gold nanoparticles have higher stability. For the ease of synthesis, gold nanoparticles are also better. On the other hand, generally silver nanostructures exhibits two-order higher SERS efficiency.
What is surface enhanced Raman spectroscopy used for?
Abstract. Surface-enhanced Raman spectroscopy (SERS) is a vibrational spectroscopy technique with sensitivity down to the single molecule level that provides fine molecular fingerprints, allowing for direct identification of target analytes.
What is the SERS effect?
The SERS effect involves the interaction of the metal surface plasmons with the electronic and vibrational states of the adsorbed molecules, under the influence of the oscillating electromagnetic radiation .
How does SERS Raman work?
SERS uses nanoscale roughened metal surfaces typically made of gold (Au) or silver (Ag). Laser excitation of these roughened metal nanostructures resonantly drives the surface charges creating a highly localized (plasmonic) light field.
Why do we use SERS?
The power of SERS lies in its ability to identify chemical species and obtain structural information in a wide variety of fields including polymer and materials science, biochemistry and biosensing, catalysis, and electrochemistry.
How do you calculate enhancement factor SERS?
The SERS enhancement factor (EF) is given by: EF= NvolIsurf/NsurfIvol where Nvol and Nsurf are the number of molecules probed in the aqueous sample and on the SERS substrates, respectively.
What are the applications of single-molecule and nanoparticle SERS?
Nanoparticle-based SERS applications include diagnostics, material identification, biological labelling, and security applications. Qian, X. M., & Nie, S. M. “Single-molecule and single-nanoparticle SERS: from fundamental mechanisms to biomedical applications.”
What are plasmonic metal nanoparticles?
Plasmonic metal nanoparticles – including gold, silver, and platinum – are highly efficient at absorbing and scattering light. By changing nanoparticle size, shape, and composition, the optical response can be tuned from the ultraviolet through the visible to the near-infrared regions of the electromagnetic spectrum.
How do plasmon resonance fields interact with nanoparticles?
This module describes how these high-intensity fields associated with the surface plasmon resonance can interact with molecules close to the nanoparticle surface to produce enhanced Raman or fluorescence signals.