scholarly journals Detection of carotenoids of halophilic prokaryotes in solid inclusions inside laboratory-grown chloride and sulfate crystals using a portable Raman spectrometer: applications for Mars exploration

2019 ◽  
Vol 366 (20) ◽  
Author(s):  
Adam Culka ◽  
Filip Košek ◽  
Aharon Oren ◽  
Lily Mana ◽  
Jan Jehlička
Keyword(s):  
Raman Spectroscopy ◽  
Carotenoid Pigments ◽  
Crystalline Layer ◽  
Raman Spectrometer ◽  
Resonance Enhancement ◽  
Mineral Assemblages ◽  
Detection Of Biomarkers ◽  
Primary Crystals ◽  
532 Nm ◽  
Portable Raman

ABSTRACT Inclusions in evaporitic minerals sometimes contain remnants of microorganisms or biomarkers, which can be considered as traces of life. Raman spectroscopy with resonance enhancement is one of the best analytical methods to search for such biomarkers in places of interest for astrobiology, including the surface and near subsurface of planet Mars. Portable Raman spectrometers are used as training tools for detection of biomarkers. Investigations of the limits and challenges of detecting biomolecules in crystals using Raman spectroscopy is important because natural occurrences often involve mineral assemblages as well as their fluid and solid inclusions. A portable Raman spectrometer with 532 nm excitation was used for detection of carotenoid biomarkers: salinixanthin of Salinibacter ruber (Bacteroidetes) and α-bacterioruberin of Halorubrum sodomense (Halobacteria) in laboratory-grown artificial inclusions in compound crystals of several chlorides and sulfates, simulating entrapment of microorganisms in evaporitic minerals. Crystals of halite (NaCl), sylvite (KCl), arcanite (K2SO4) and tschermigite ((NH4)Al(SO4)2·12H2O) were grown from synthetic solutions that contained microorganisms. A second crystalline layer of NaCl or K2SO4 was grown subsequently so that primary crystals containing microorganisms are considered as solid inclusions. A portable Raman spectrometer with resonance enabling excitation detected signals of both carotenoid pigments. Correct positions of diagnostic Raman bands corresponding to the specific carotenoids were recorded.

scholarly journals Resonance-Enhanced Raman Spectroscopy on Explosives Vapor at Standoff Distances

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Anneli Ehlerding ◽  
Ida Johansson ◽  
Sara Wallin ◽  
Henric Östmark
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Wavelength Range ◽  
Vapor Phase ◽  
Cross Sections ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Resonance Enhancement ◽  
Enhancement Factors ◽  
532 Nm

Resonance-enhanced Raman spectroscopy has been used to perform standoff measurements on nitromethane (NM), 2,4-DNT, and 2,4,6-TNT in vapor phase. The Raman cross sections for NM, DNT, and TNT in vapor phase have been measured in the wavelength range 210–300 nm under laboratory conditions, in order to estimate how large resonance enhancement factors can be achieved for these explosives. The results show that the signal is enhanced up to 250,000 times for 2,4-DNT and up to 60,000 times for 2,4,6-TNT compared to the nonresonant signal at 532 nm. Realistic outdoor measurements on NM in vapor phase at 13 m distance were also performed, which indicate a potential for resonance Raman spectroscopy as a standoff technique for detection of vapor phase explosives. In addition, the Raman spectra of acetone, ethanol, and methanol were measured at the same wavelengths, and their influence on the spectrum from NM was investigated.

scholarly journals Quantitative visualization of photosynthetic pigments in tea leaves based on Raman spectroscopy and calibration model transfer

Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Jianjun Zeng ◽  
Wen Ping ◽  
Alireza Sanaeifar ◽  
Xiao Xu ◽  
Wei Luo ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Photosynthetic Pigments ◽  
Spectral Model ◽  
Calibration Model ◽  
Tea Leaves ◽  
Raman Spectrometer ◽  
Quantitative Visualization ◽  
Model Transfer ◽  
Portable Raman

Abstract Background Photosynthetic pigments participating in the absorption, transformation and transfer of light energy play a very important role in plant growth. While, the spatial distribution of foliar pigments is an important indicator of environmental stress, such as pests, diseases and heavy metal stress. Results In this paper, in situ quantitative visualization of chlorophyll and carotenoid was realized by combining the Raman spectroscopy with calibration model transfer, and a laboratory Raman spectral model was successfully extended to a portable field spectral measurement. Firstly, a nondestructive and fast model for determination of chlorophyll and carotenoid in tea leaf was established based on confocal micro-Raman spectrometer in the laboratory. Then the spectral model was extended to a real-time foliar map scanning spectra of a field portable Raman spectrometer through calibration model transfer, and the spectral variation between the confocal micro-Raman spectrometer in the laboratory and the portable Raman spectrometer were effectively corrected by the direct standardization (DS) algorithm. The portable map scanning Raman spectra of the tea leaves after the model transfer were got into the established quantitative determination model to predict the concentration of photosynthetic pigments at each pixel of the tea leaves. The predicted photosynthetic pigments concentration of each pixel was imaged to illustrate the distribution map of foliar pigments. Statistical analysis showed that the predicted pigment contents were highly correlated with the real contents. Conclusions It can be concluded that the Raman spectroscopy was applicable for in situ, non-destructive and rapid quantitative detecting and imaging of photosynthetic pigment concentration in tea leaves, and the spectral detection model established based on the laboratory Raman spectrometer can be applied to a portable field spectrometer for quantitatively imaging of the foliar pigments.

scholarly journals The Ring Monstrance from the Loreto treasury in Prague: handheld Raman spectrometer for identification of gemstones

2016 ◽  
Vol 374 (2082) ◽  
pp. 20160042 ◽  
Author(s):  
Jan Jehlička ◽  
Adam Culka ◽  
Markéta Baštová ◽  
Petr Bašta ◽  
Jaroslav Kuntoš
Keyword(s):  
Raman Spectroscopy ◽  
Eighteenth Century ◽  
Czech Republic ◽  
Scattered Light ◽  
Good Correspondence ◽  
Laser Illumination ◽  
Raman Spectrometer ◽  
Unambiguous Detection ◽  
Cultural Heritage Objects ◽  
Portable Raman

A miniature lightweight portable Raman spectrometer and a palm-sized device allow for fast and unambiguous detection of common gemstones mounted in complex jewels. Here, complex religious artefacts and the Ring Monstrance from the Loreto treasury (Prague, Czech Republic; eighteenth century) were investigated. These discriminations are based on the very good correspondence of the wavenumbers of the strongest Raman bands of the minerals. Very short laser illumination times and efficient collection of scattered light were sufficient to obtain strong diagnostic Raman signals. The following minerals were documented: quartz and its varieties, beryl varieties (emerald), corundum varieties (sapphire), garnets (almandine, grossular), diamond as well as aragonite in pearls. Miniature Raman spectrometers can be recommended for common gemmological work as well as for mineralogical investigations of jewels and cultural heritage objects whenever the antiquities cannot be transported to a laboratory. This article is part of the themed issue ‘Raman spectroscopy in art and archaeology’.

Study on Detection of Carbaryl Pesticides by Using Surface-Enhance Raman Spectroscopy

2020 ◽  
Vol 853 ◽  
pp. 97-101
Author(s):  
Chaiwat Chakaja ◽  
Saksorn Limwichean ◽  
Noppadon Nuntawong ◽  
Pitak Eiamchai ◽  
Sukon Kalasung ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Raman Scattering ◽  
Exposure Time ◽  
Laser Power ◽  
Limit Of Detection ◽  
Surface Enhance Raman Spectroscopy ◽  
Raman Spectrometer ◽  
Surface Enhanced Raman ◽  
Solid Form ◽  
Portable Raman

In this research, the Ag nanorod structure was used as surface enhanced Raman scattering (SERS) chip which provides a sensitive detection signal for trace analysis of carbaryl pesticide. Carbaryl in solid form was measured by using the standard Raman spectroscopy to investigate the spectrum. Carbaryl at various concentrations was prepared in acetonitrile and dropped on the SERS chip for measuring Raman spectrum by a portable Raman spectrometer. The measurement condition including laser power and exposure time were studied to test the performance of SERS chip for carbaryl detection. From the results, the SERS chip useful for enhancing the Raman scattering signal which was increased depending on the laser power and exposure time. Carbaryl can be detected on SERS chip couple with the portable Raman spectrometer with the limit of detection of 10-5 M.

scholarly journals Quantitative visualization of photosynthetic pigments in tea leaves based on Raman spectroscopy and calibration model transfer

2020 ◽  
Author(s):  
Jianjun Zeng ◽  
Wen Ping ◽  
Alireza Sanaeifar ◽  
Xiao Xu ◽  
Wei Luo ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Photosynthetic Pigments ◽  
Spectral Model ◽  
Calibration Model ◽  
Tea Leaves ◽  
Raman Spectrometer ◽  
Quantitative Visualization ◽  
Model Transfer ◽  
Portable Raman

Abstract Background: Photosynthetic pigments participating in the absorption, transformation and transfer of light energy play a very important role in plant growth. While, the spatial distribution of foliar pigments is an important indicator of environmental stress, such as pests, diseases and heavy metal stress. Results: In this paper, in situ quantitative visualization of chlorophyll and carotenoid was realized by combining the Raman spectroscopy with calibration model transfer, and a laboratory Raman spectral model was successfully extended to a portable field spectral measurement. Firstly, a nondestructive and fast model for determination of chlorophyll and carotenoid in tea leaf was established based on confocal micro-Raman spectrometer in the laboratory. Then the spectral model was extended to a real-time foliar map scanning spectra of a field portable Raman spectrometer through calibration model transfer, and the spectral variation between the confocal micro-Raman spectrometer in the laboratory and the portable Raman spectrometer were effectively corrected by the direct standardization (DS) algorithm. The portable map scanning Raman spectra of the tea leaves after the model transfer were got into the established quantitative determination model to predict the concentration of photosynthetic pigments at each pixel of the tea leaves. The predicted photosynthetic pigments concentration of each pixel was imaged to illustrate the distribution map of foliar pigments. Statistical analysis showed that the predicted pigment contents were highly correlated with the real contents.Conclusions: It can be concluded that the Raman spectroscopy was applicable for in situ, non-destructive and rapid quantitative detecting and imaging of photosynthetic pigment concentration in tea leaves, and the spectral detection model established based on the laboratory Raman spectrometer can be applied to a portable field spectrometer for quantitatively imaging of the foliar pigments.

Sign in / Sign up

Export Citation Format

Share Document