scholarly journals BCAbox Algorithm Expands Capabilities of Raman Microscope for Single Organelles Assessment

Biosensors ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 106 ◽  
Author(s):  
Andrey N. Kuzmin ◽  
Artem Pliss ◽  
Alex Rzhevskii ◽  
Adrian Lita ◽  
Mioara Larion
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Live Cells ◽  
Spectroscopy Instrumentation ◽  
Precise Analysis ◽  
Express Analysis ◽  
Immediate Analysis ◽  
Software Toolbox ◽  
Cellular Organelles

Raman microspectroscopy is a rapidly developing technique, which has an unparalleled potential for in situ proteomics, lipidomics, and metabolomics, due to its remarkable capability to analyze the molecular composition of live cells and single cellular organelles. However, the scope of Raman spectroscopy for bio-applications is limited by a lack of software tools for express-analysis of biomolecular composition based on Raman spectra. In this study, we have developed the first software toolbox for immediate analysis of intracellular Raman spectra using a powerful biomolecular component analysis (BCA) algorithm. Our software could be easily integrated with commercial Raman spectroscopy instrumentation, and serve for precise analysis of molecular content in major cellular organelles, including nucleoli, endoplasmic reticulum, Golgi apparatus, and mitochondria of either live or fixed cells. The proposed software may be applied in broad directions of cell science, and serve for further advancement and standardization of Raman spectroscopy.

Laser wavelength selection for Raman spectroscopy of microbial pigments in situ in Antarctic desert ecosystem analogues of former habitats on Mars

2002 ◽  
Vol 1 (4) ◽  
pp. 333-348 ◽  
Author(s):  
Howell G.M. Edwards ◽  
Emma M. Newton ◽  
David D. Wynn-Williams ◽  
David Dickensheets ◽  
Chris Schoen ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Laser Wavelength ◽  
Desert Ecosystem ◽  
Nostoc Commune ◽  
Raman Spectrometry ◽  
Desert Ecosystems ◽  
Long Wavelength ◽  
Life On Earth

The vital ultraviolet- (UV-) protective and photosynthetic pigments of cyanobacteria and lichens (microbial symbioses) that dominate primary production in Antarctic desert ecosystems auto-fluoresce at short wavelengths. We therefore use a long-wavelength (1064 nm) infrared laser for non-intrusive in situ Raman spectrometry of their ecologically significant compounds (especially pigments). To confirm that the power loss at this longer wavelength is justified to avoid swamping by background fluorescence, we compared Raman spectra obtained with excitation at 1064, 852, 830, 785, 633 and 515 nm. These are typical of lasers used for Raman spectroscopy. We analysed communities of the cyanobacterium Nostoc commune and the highly pigmented lichens Acarospora chlorophana and Caloplaca saxicola. These require screening compounds (e.g. pigments such as scytonemin in cyanobacteria and rhizocarpic acid in the fungal symbiont of lichens). They are augmented by quenching pigments (e.g. carotenoids) to dissipate the energy of free radicals generated by penetrating UV. We also analysed organisms having avoidance strategies (e.g. endolithic communities within translucent rocks, including the common cyanobacterium Chroococcidiopsis). These require accessory pigments for photosynthesis at very low light intensities. Although some organisms gave useable Raman spectra with short-wavelength lasers, 1064 nm was the only excitation that was consistently excellent for all organisms. We conclude that a 1064 nm Raman spectrometer, miniaturized using an InGaAs detector, is the optimal instrument for in situ studies of pigmented microbial communities at the limits of life on Earth. This has practical potential for the quest for biomolecules residual from any former surface life on Mars.

Oxide Scale Formation on Iron-Chromium Alloys in Elevated Temperature Air Environments

CORROSION ◽  
1981 ◽  
Vol 37 (12) ◽  
pp. 700-711 ◽  
Author(s):  
P. Fabis ◽  
R. Heidersbach ◽  
C. Brown ◽  
T. Rockett
Keyword(s):  
Raman Spectroscopy ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Experimental Program ◽  
Oxide Scales ◽  
Chromium Alloys ◽  
Spectroscopy Instrumentation ◽  
Commercial Iron ◽  
Iron Chromium

Abstract Oxide scales formed on metals at elevated temperatures may be different, both chemically and structurally, from the scales on the metal once it has cooled to room temperature. This paper discusses Raman spectroscopy instrumentation for the in-situ identification of scales formed on metal surfaces exposed to gaseous environments. The results of an experimental program to characterize scales formed on two commercial iron-chromium alloys, AISI 446 and 502, in air and oxygen environments are also presented.

scholarly journals In Situ Raman Spectroscopy as a Tool for Discerning Subtle Structural Differences between Commercial (Ce,Zr)O2-Based OSC Materials of Identical Composition

Catalysts ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 462
Author(s):  
Chrysanthi Andriopoulou ◽  
Deb Harris ◽  
Hazel Stephenson ◽  
Angelos M. Efstathiou ◽  
Soghomon Boghosian
Keyword(s):  
Raman Spectroscopy ◽  
Metal Oxide ◽  
Raman Spectra ◽  
Mixed Metal Oxide ◽  
Oxide Materials ◽  
In Situ Raman Spectroscopy ◽  
Aqueous Chemistry ◽  
Mixed Metal ◽  
In Situ Raman

In situ Raman spectroscopy was used at temperatures in the 50–480 °C range under oxidizing (20% O2/He) and reducing (5% H2/He) flowing gas atmospheres to compare the spectra obtained for a series of industrial rare earth doped CexZr1−xO2−δ oxygen storage capacity (OSC) mixed metal oxide materials of identical at % composition, which were prepared by the same chemical synthesis route, in which one synthesis parameter of the aqueous chemistry was slightly varied. The Raman fingerprint of the anionic sublattice is very sensitive to O atom relocations within the bulk of the material matrix and to the pertinent defect topology in each case. A protocol of sequential Raman measurements and analysis was proposed to discern subtle differences between the oxygen vacancy and defect topologies of the examined materials. It can be concluded that for two materials under comparison for their structures, identical Raman spectra are obtained only if the procedures followed for their preparation are identical; a slight variation of one single parameter (e.g., in the aqueous chemistry stage) results in discernible differences in the Raman spectra. The proposed procedure can serve as a tool for proving or disproving infringement of IPR (Intellectual Property Rights) protected preparation methods of ceria-based mixed metal oxide materials.

scholarly journals In situ Raman spectroscopy of samarium ions in molten LiCl-KCl eutectic

2019 ◽  
Author(s):  
Vickram J. Singh ◽  
Christopher D. Bruneau ◽  
Dev Chidambaram
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Chemical Reduction ◽  
Inert Atmosphere ◽  
Eutectic System ◽  
In Situ Raman Spectroscopy ◽  
In Situ Raman ◽  
Samarium Chloride ◽  
And Behavior

A fiber-based Raman spectroscopy system was commissioned in an inert atmosphere for in situ analysis of high temperature molten salts. Speciation of samarium chloride was studied in the LiCl-KCl eutectic system at 500 °C. Raman spectra indicated trivalent samarium forms an octahedral SmCl63- complex with two detectable vibration modes. Chemical reduction experiments were conducted to investigate the coordination of divalent samarium in the same eutectic salt. The resulting spectra are reported and discussed in terms of complex formation and behavior of divalent samarium ions. Trivalent samarium was electrochemically reduced in situ and Raman spectra obtained were compared with those resulting from chemical reduction experiments. The spectra suggest divalent samarium ions form in LiCl-KCl only temporarily and spontaneously disproportionate into a mixture of trivalent samarium ions and metallic samarium.

Spatial characterization of Doped Sic Wafers

1998 ◽  
Vol 512 ◽  
Author(s):  
J. C. Burton ◽  
L. Sun ◽  
M. Pophristic ◽  
J. Li ◽  
F. H. Long ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Carrier Concentration ◽  
Raman Spectra ◽  
Longitudinal Optical ◽  
Plasmon Mode ◽  
Nitrogen Doped ◽  
Spatial Characterization ◽  
Sic Wafer

ABSTRACTRaman spectroscopy has been used to investigate wafers of both 4H-SiC and 6H-SiC. The wafers studied were semi-insulating and n-type (nitrogen) doped with concentrations between 2.1 × 1018 cm−3 and 1.2 × 1019 cm−3. Significant coupling of the A1 longitudinal optical (LO) phonon to the plasmon mode was observed. The position of this peak shows a direct correlation with the carrier concentration. Examination of the Raman spectra from different positions on the wafer yielded a rudimentary spatial map of the carrier concentration. This data is compared with a resistivity map of the wafer. These results suggest that Raman spectroscopy of the LO phonon-plasmon mode can be used as a noninvasive, in situ diagnostic for SiC wafer production and substrate evaluation.

In situ Identification of Thin-Layer Chromatography Fractions by FT Raman Spectroscopy

1992 ◽  
Vol 46 (4) ◽  
pp. 597-601 ◽  
Author(s):  
Neil J. Everall ◽  
John M. Chalmers ◽  
Ian D. Newton
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Total Sample ◽  
Limiting Factor ◽  
Large Area ◽  
Background Fluorescence ◽  
Ft Raman Spectroscopy ◽  
Favorable Case ◽  
Ft Raman

The use of near-IR-FT Raman spectroscopy for the in situ analysis of fractions on TLC plates is described. The detection of additives in use in the plastics industry is used as an example. Reasonable-quality spectra were obtained from sample loadings equivalent to about 3 μg mm−2 in the most favorable case. Background fluorescence was not a problem, either from the adsorbent or the adsorbate, even when fluorescor was present to aid spot visualization. Similarly, staining with iodine to identify spot positions did not degrade the FT Raman spectra. When a mixture of three additives (200 μg of each) was eluted on a silica TLC plate, two of the additives gave good Raman spectra, sufficient for identification. The third component, a weaker scatterer, had spread over such a large area that the concentration was too weak to give a Raman spectrum visible above the background features from the TLC adsorbent. The concentration of the eluted spot is the limiting factor in this approach since the Raman experiment samples only about 1 mm2 of the total sample area. However, component detection is clearly feasible with the use of this technique, and advances in detector technology should substantially reduce the sample loadings required to effect identification, although it must be realized that background Raman features from the TLC adsorbent will ultimately obscure the spectrum of very dilute loadings of additives. In such cases, sample concentration on the plate will be necessary. A brief comparison with conventional Raman spectra obtained with 514-nm excitation is also made. While good spectra of one additive on silica were obtained, this approach could not be used with plates that contained added fluorescor or that had been stained with iodine for spot visualization, owing to intense background fluorescence. The approach was also prone to fluorescence form the TLC fraction itself and sample degradation.

scholarly journals Raman Spectroscopy and Machine Learning for IDH Genotyping of Unprocessed Glioma Biopsies

Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 4196
Author(s):  
Tommaso Sciortino ◽  
Riccardo Secoli ◽  
Ester d’Amico ◽  
Sara Moccia ◽  
Marco Conti Nibali ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Classification Performance ◽  
Support Vector ◽  
Wild Type ◽  
Raman Analysis ◽  
Mutational Status ◽  
Accuracy And Precision ◽  
Glioma Tumors

Isocitrate dehydrogenase (IDH) mutational status is pivotal in the management of gliomas. Patients with IDH-mutated (IDH-MUT) tumors have a better prognosis and benefit more from extended surgical resection than IDH wild-type (IDH-WT). Raman spectroscopy (RS) is a minimally invasive optical technique with great potential for intraoperative diagnosis. We evaluated the RS’s ability to characterize the IDH mutational status onto unprocessed glioma biopsies. We extracted 2073 Raman spectra from thirty-eight unprocessed samples. The classification performance was assessed using the eXtreme Gradient Boosted trees (XGB) and Support Vector Machine with Radial Basis Function kernel (RBF-SVM). Measured Raman spectra displayed differences between IDH-MUT and IDH-WT tumor tissue. From the 103 Raman shifts screened as input features, the cross-validation loop identified 52 shifts with the highest performance in the distinction of the two groups. Raman analysis showed differences in spectral features of lipids, collagen, DNA and cholesterol/phospholipids. We were able to distinguish between IDH-MUT and IDH-WT tumors with an accuracy and precision of 87%. RS is a valuable and accurate tool for characterizing the mutational status of IDH mutation in unprocessed glioma samples. This study improves RS knowledge for future personalized surgical strategy or in situ target therapies for glioma tumors.

Submicron Simultaneous IR and Raman Spectroscopy (IR+Raman): Breakthrough Developments in Optical Photothermal IR (O-PTIR) Combined for Enhanced Failure Analysis

2019 ◽  
Author(s):  
Jay Anderson ◽  
Mustafa Kansiz ◽  
Michael Lo ◽  
Curtis Marcott
Keyword(s):  
Raman Spectroscopy ◽  
Failure Analysis ◽  
Data Quality ◽  
Raman Spectra ◽  
Spatial Resolution ◽  
Far Field ◽  
Field Mode ◽  
Microscopic Scale ◽  
Analytical Tools ◽  
Ir And Raman

Abstract Failure analysis of organics at the microscopic scale is an increasingly important requirement, with traditional analytical tools such as FTIR and Raman microscopy, having significant limitations in either spatial resolution or data quality. We introduce here a new method of obtaining Infrared microspectroscopic information, at the submicron level in reflection (far-field) mode, called Optical-Photothermal Infrared (O-PTIR) spectroscopy, that can also generate simultaneous Raman spectra, from the same spot, at the same time and with the same spatial resolution. This novel combination of these two correlative techniques can be considered to be complimentary and confirmatory, in which the IR confirms the Raman result and vice-versa, to yield more accurate and therefore more confident organic unknowns analysis.

In Situ Raman Spectroscopy Studies on La2CaB10O19 Crystal Growth

2020 ◽  
Vol 20 (10) ◽  
pp. 6604-6609
Author(s):  
Shanshan Liu ◽  
Guochun Zhang ◽  
Kai Feng ◽  
Yanyang Han ◽  
Tao He ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Crystal Growth ◽  
In Situ Raman Spectroscopy ◽  
In Situ Raman ◽  
Spectroscopy Studies
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