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Materials
Raman spectroscopy is used in chemistry to identify molecules and study chemical bonding and intramolecular bonds. Because vibrational frequencies are specific to a molecule's chemical bonds and symmetry (the fingerprint region of organic molecules is in the wavenumber range 500–1,500 cm−1), Raman provides a fingerprint to identify molecules. For instance, Raman and IR spectra were used to determine the vibrational frequencies of SiO, Si2O2, and Si3O3 on the basis of normal coordinate analyses. Raman is also used to study the addition of a substrate to an enzyme.

In solid-state physics, Raman spectroscopy is used to characterize materials, measure temperature, and find the crystallographic orientation of a sample. As with single molecules, a solid material can be identified by characteristic phonon modes. Information on the population of a phonon mode is given by the ratio of the Stokes and anti-Stokes intensity of the spontaneous Raman signal. Raman spectroscopy can also be used to observe other low frequency excitations of a solid, such as plasmons, magnons, and superconducting gap excitations. Distributed temperature sensing (DTS) uses the Raman-shifted backscatter from laser pulses to determine the temperature along optical fibers. The orientation of an anisotropic crystal can be found from the polarization of Raman-scattered light with respect to the crystal and the polarization of the laser light, if the crystal structure’s point group is known.

In nanotechnology, a Raman microscope can be used to analyze nanowires to better understand their structures, and the radial breathing mode of carbon nanotubes is commonly used to evaluate their diameter.

Raman active fibers, such as aramid and carbon, have vibrational modes that show a shift in Raman frequency with applied stress. Polypropylene fibers exhibit similar shifts.

In solid state chemistry and the bio-pharmaceutical industry, Raman spectroscopy can be used to not only identify active pharmaceutical ingredients (APIs), but to identify their polymorphic forms, if more than one exist. For example, the drug Cayston (aztreonam), marketed by Gilead Sciences for cystic fibrosis, can be identified and characterized by IR and Raman spectroscopy. Using the correct polymorphic form in bio-pharmaceutical formulations is critical, since different forms have different physical properties, like solubility and melting point.

Raman spectroscopy has been used in several research projects as a means to detect explosives from a safe distance using laser beams.

Biology
Raman spectroscopy has a wide variety of applications in biology and medicine. It has helped confirm the existence of low-frequency phonons in proteins and DNA,   promoting studies of low-frequency collective motion in proteins and DNA and their biological functions. Raman reporter molecules with olefin or alkyne moieties are being developed for tissue imaging with SERS-labeled antibodies. Raman spectroscopy has also been used as a noninvasive technique for real-time, in situ biochemical characterization of wounds. Multivariate analysis of Raman spectra has enabled development of a quantitative measure for wound healing progress. Spatially offset Raman spectroscopy (SORS), which is less sensitive to surface layers than conventional Raman, can be used to discover counterfeit drugs without opening their packaging, and to non-invasively study biological tissue. A huge reason why Raman spectroscopy is so useful in biological applications is because its results often do not face interference from water molecules, due to the fact that they have permanent dipole moments, and as a result, the Raman scattering cannot be picked up on. This is a large advantage, specifically in biological applications. Raman spectroscopy also has a wide usage for studying biominerals. Lastly, Raman gas analyzers have many practical applications, including real-time monitoring of anesthetic and respiratory gas mixtures during surgery.

Raman Spectroscopy is being further developed so it could be used in the clinical setting. Raman4Clinic is a European organization that is working on incorporating Raman Spectroscopy techniques in the medical field. They are currently working on different projects, one of them being monitoring cancer using bodily fluids such as urine and blood samples which are easily accessible. This technique would be less stressful on the patients than constantly having to take biopsies which are not always risk free.

Cancer is a major cause of death worldwide, and many scientists are working toward new methods to detect cancer. Fluorescence spectroscopy can be used, but often has to rely on exogenous fluorescent-labeled tags. Raman spectroscopy is a technique that is capable of rapid, label-free measurements of tissue and can be used to detect some cancers. Raman spectra are often processed using machine-learning chemometrics for the relevant statistical analysis. Real-time in vivo skin cancer detection showed promise using a Raman-chemometrics method. Raman microscopy was shown to detect differences in low/high-grade bladder cancer cell lines based on urine analysis. Finally, a contact Raman probe was developed that showed promise for detecting cancer cells in the brain during surgery.

Microfluidics
Raman spectroscopy can be employed as a robust detection and characterization technique when coupled to microfluidic assays. Using a fiber optic probe on a chip, Raman spectroscopy was able to measure the polymerization of methacrylate in droplets by the depletion of C=C stretching. The immiscibility of oil and water is a tenet of droplet-based microfluidics. To better understand their interaction, the position and thickness of the oil-water interface for different oils was studied using Raman. The combination of microfluidics and Raman spectroscopy can also be applied to biological systems. Using two-beam optical traps and linear discriminant analysis, cancerous and non-cancerous blood cells are able to be classified which is a step toward automated cell sorting. Microplastics and nanoplastics, abundant ocean pollutants, pose potential risks for marine life. Combining field-flow fractionation with optical tweezers, Raman spectroscopy is able to identify and characterize different nanoplastics in solution. Due to the small sample volume and low Raman cross-section of many analytes, a pre-concentration or trapping step is often required to achieve adequate Raman signal.

The low signal challenge can be overcome by using surface-enhanced Raman spectroscopy, which enhances the Raman scattering effect by adsorbing the analyte of interest onto metal particles. SERS detection can be integrated with microfluidic systems by flowing silver/gold colloids and analyte through a channel and exciting the system with a confocal Raman microscope. Alternatively, SERS-active metals can be implemented directly into the microchannel. SERS was coupled to open-surface microfluidics for trace explosive vapor detection as an analytical tool to supplement sniffer dogs. Trace analysis in liquids is also possible and has been shown to rapidly detect methamphetamine in saliva and melamine in whole milk. SERS combined with droplet-based microfluidics is able to perform single cell analysis and has been used to study single prostate cancer cells using SERS-active biotags.

Art and cultural heritage
Raman spectroscopy is an efficient and non-destructive way to investigate works of art and cultural heritage artifacts, in part because it is a non-invasive process which can be applied in situ. It can be used to analyze the corrosion products on the surfaces of artifacts (statues, pottery, etc.), which can lend insight into the corrosive environments experienced by the artifacts. The resulting spectra can also be compared to the spectra of surfaces that are cleaned or intentionally corroded, which can aid in determining the authenticity of valuable historical artifacts.

It is capable of identifying individual pigments in paintings and their degradation products, which can provide insight into the working method of an artist in addition to aiding in authentication of paintings. It also gives information about the original state of the painting in cases where the pigments have degraded with age.

In addition to paintings and artifacts, Raman spectroscopy can be used to investigate the chemical composition of historical documents (such as the Book of Kells), which can provide insight about the social and economic conditions when they were created. It also offers a noninvasive way to determine the best method of preservation or conservation of such cultural heritage artifacts, by providing insight into the causes behind deterioration.

The IRUG (Infrared and Raman Users Group) Spectral Database is a rigorously peer-reviewed online database of IR and Raman reference spectra for cultural heritage materials such as works of art, architecture, and archaeological artifacts. The database is open for the general public to peruse, and includes interactive spectra for over a hundred different types of pigments and paints.