How does tip enhanced Raman spectroscopy work?

TERS (Tip Enhanced Raman Spectroscopy) brings Raman spectroscopy into nanoscale resolution imaging1-6. TERS is a super-resolution chemical technique. A TERS system is based on a metallic tip (generally made of gold or silver) employed to concentrate the incident light field at the apex.

What is Surface-Enhanced Resonance Raman Spectroscopy?

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 does Raman spectroscopy determine?

Raman Spectroscopy is a non-destructive chemical analysis technique which provides detailed information about chemical structure, phase and polymorphy, crystallinity and molecular interactions. It is based upon the interaction of light with the chemical bonds within a material.

How sensitive is Raman Spectroscopy?

The negative predictive value was 91%; Raman spectrometry correctly identified 20 of 22 compounded pharmaceutical formulations that did not contain active pharmaceutical ingredients. Raman testing sensitivity was calculated to be 98% and specificity was 100%.

What is Raman scattering of light?

Raman scattering is an optical process where incoming excitation light interacting with a sample produces scattered light that is lessened in energy by the vibrational modes of the chemical bonds of the specimen.

How does surface enhanced Raman work?

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 surface enhanced fluorescence?

Surface enhanced fluorescence (SEF) is a phenomenon first observed in the 1970’s that occurs when a fluorophore is placed near the high electromagnetic fields at the surface of a plasmonic metal nanoparticle, enhancing the fluorophore emission intensity by orders of magnitude. …

What are the advantages of Raman Spectroscopy?

Advantages of Raman Spectroscopy no sample preparation needed. not interfered by water. non-destructive. highly specific like a chemical fingerprint of a material.

Which phenomenon takes place in Raman Spectroscopy?

4 Raman spectroscopy. Raman effect takes place when light enters in a molecule and interacts with the electron density of the chemical bond causing electromagnetic field in the molecule leading to vibrational and deformation of frequency shift. The incident photon excites the electron into a virtual state.

Which type of scattering is the strongest?

Another finding is that forward scattering is stronger than backward scattering, because the relative phase differences of contributions from different scattering locations on the particles become smaller. Mie scattering is particularly relevant for meteorological optics, but also in the biomedical area, for example.

What is the difference between Raman and IR spectroscopy?

Raman spectroscopy depends on a change in polarizability of a molecule, whereas IR spectroscopy depends on a change in the dipole moment. Raman spectroscopy measures relative frequencies at which a sample scatters radiation, unlike IR spectroscopy which measures absolute frequencies at which a sample absorbs radiation.

What are the types of scattering?

There are three different types of scattering: Rayleigh scattering, Mie scattering, and non-selective scattering.

What is tip enhanced Raman scattering, or ters?

SERS/TERS Boosting Raman. SERS (surface-enhanced Raman scattering) and TERS (tip-enhanced Raman scattering) both involve the use of metallic particles or layers to boost the amount of Raman scattering from molecules very SERS. SERS normally uses either a colloidal suspension of metal (e.g. TERS.

What are the optical components in a Raman spectrometer?

The other key optical component in a Raman spectrometer is the mirrors . As the Raman effect is so weak, it is important that the mirrors have maximum reflectance over the desired wavelength region to minimize losses. This wavelength range may need to be quite broad for instruments where the excitation wavelength can be changed.

What is a Raman spectrometer?

Raman Laser Spectrometer (RLS) is a miniature Raman spectrometer that is part of the science payload on board the European Space Agency’s Rosalind Franklin rover, tasked to search for biosignatures and biomarkers on Mars.