How is Raman spectroscopy used in nanomaterials?
Raman spectroscopy can be used as a tool to identify the phases and phase transitions of various nanoparticles and other nanostructured materials, determine which regions of a nanomaterial are amorphous or crystalline, whether there are any defects present in the nanomaterial, determine the size (diameter, lateral …
What are silicon nanoparticles?
Silica nanoparticles (SiNPs) or silicon dioxide are amorphous substances that have a spherical form. They can be produced in a variety of shapes and sizes, and the properties of their surfaces can be easily changed to suit several purposes.
How does surface-enhanced Raman work?
Surface-enhanced Raman scattering, or SERS, is a commonly used sensing technique in which inelastic light scattering (Figure 1) by molecules is greatly enhanced (by factors up to 108 or even larger, enabling single-molecule (SM) SERS in some cases) when the molecules are adsorbed onto corrugated metal surfaces such as …
Is Raman surface sensitive?
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 band in Raman?
Raman bands of nucleic acids originate from in-plane vibrations of the nucleic acid bases (adenine, guanine, cytosine, thymine and uracil) and from the furanose-phosphate backbone. In general, Raman spectra of DNA or RNA reveal structural information about base stacking and interbase hydrogen bonding interactions.
How do silica nanoparticles work?
Synthesis of Silica Nanoparticles This technique utilizes a silica precursor, tetraethyl orthosilicate (TEOS) which in the presence of ethanol and ammonium hydroxide (NH2OH), undergoes hydrolysis followed by a polycondensation reaction to produce non-porous silica particles with sizes less than 200 nm.
How do you make silicon nanoparticles?
Spherical and amorphous silica nanoparticles can be prepared by the hydrolysis reaction of TEOS in ethanol using water and ammonia using sol-gel method. The particle size of nano silica can be controlled by adding span 20, span 40 and span 60 surfactants.
What is meant by Raman effect?
Raman effect, change in the wavelength of light that occurs when a light beam is deflected by molecules. When a beam of light traverses a dust-free, transparent sample of a chemical compound, a small fraction of the light emerges in directions other than that of the incident (incoming) beam.
What is surface enhanced resonance Raman scattering?
Surface-enhanced resonance Raman scattering (SERRS) is a sensitive and selective method for the characterization of sites in biomolecules, which have an electronic transition at energy close to or coincident with the laser frequency used.
What are D and G bands in Raman spectra?
The ratio of intensity of D/G bands is a measure of the defects present on graphene structure. The G band is a result of in-plane vibrations of SP2 bonded carbon atoms whereas the D band is due to out of plane vibrations attributed to the presence of structural defects.
Is the nanoparticle composed of SiO2 regions with Unlike networks?
In this model the overall nanoparticle is constituted by SiO 2 regions with unlike network. For the interior part, the core, a bulk-like network was proposed in [19], [21], whereas in [4], [14] differences between the core and bulk network were suggested.
Is the core network of nanoparticles similar to the bulk material?
Furthermore, by studying nanoparticles with different sizes (diameters from 40 to 7 nm) and applying the shell-model we can suggest that the core network of the nanoparticles is close to the one encountered in the bulk materials.
What is peak position of R band in Raman spectroscopy?
In the Raman spectra the peak position (ω R) of the R band at about 440 cm − 1 (mainly generated by the oxygen atom bending in the Si–O–Si linkages [15]) is observed at higher energies with respect to the bulk [3], [12].
Can Raman spectroscopy identify ductal carcinoma?
This study uses the powerful fingerprint features of Raman spectroscopy to distinguish different types of breast tissues including normal breast tissues (NB), fibroadenoma (FD), atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS), and invasive ductal carcinoma (IDC).