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Raman spectra

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https://www.readbyqxmd.com/read/28551429/application-of-1d-and-2d-solid-state-nmr-spectroscopy-to-the-characterization-of-morphine-morphine-hydrochloride-and-their-hydrates
#1
C B Romañuk, Y Garro-Linck, M S Alves de Santana, R H Manzo, A P Ayala, G A Monti, A K Chattah, M E Olivera
The detailed knowledge of the solid forms of a drug is a key element in pharmaceutical development. Morphine, is an opiate alkaloidwidely used to treat severe acute and chronic pain. Much of the available information on its solid state dates from several decades ago. In order to obtain updated and reliable information1D and 2D solid-state NMR spectroscopy were used, and complemented with powder X-ray diffraction, FTIR and RAMAN spectroscopy and thermal analysis.(13)C CPMAS 1D spectra accomplish a complete identification of the related forms of morphine...
May 24, 2017: Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28551122/a-recyclable-silver-ions-specific-surface-enhanced-raman-scattering-sers-sensor
#2
Dan Sun, Guohua Qi, Fanghao Cao, Weiqing Xu, Qidan Chen, Shuping Xu
A highly sensitive and recyclable surface-enhanced Raman scattering (SERS) chip sensor is designed for the determination of silver ions. It is based on the specific reversible binding between silver ions and glucose oxidase (GOD). The sensing chip is made by layer-by-layer assembling GOD on a metal nanoparticle-assembled, SERS-active chip with a positive charged polyelectrolyte as a linker. Iso-alloxazine, a chromophore in flavin adenine dinucleotide (FAD) in GOD, coordinates with silver ions, which causes significant variation in SERS spectra of GOD...
August 15, 2017: Talanta
https://www.readbyqxmd.com/read/28548670/oxocomplexes-of-u-vi-with-8-hydroxyquinoline-5-sulfonate-in-solution-structural-studies-and-photophysical-behaviour
#3
M Luísa Ramos, Licínia L G Justino, Rui Barata, Telma Costa, Bernardo A Nogueira, Rui Fausto, Hugh D Burrows
Multinuclear ((1)H and (13)C) NMR, and Raman spectroscopy, combined with DFT calculations, provide detailed information on the complexation between U(vi) oxoions and 8-hydroxyquinoline-5-sulfonate (8-HQS) in aqueous solution. Over the concentration region studied, U(vi) oxoions (uranyl ions) form one dominant complex with 8-HQS in water in the pH range 3-6, a mononuclear 1 : 2 (metal : ligand) complex, with the metal centre (UO2(2+)) coordinated to two 8-HQS ligands, together with one or more water molecules...
May 26, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28542948/the-capability-of-raman-microspectroscopy-to-differentiate-printing-inks
#4
Chelsea E Johnson, Paul Martin, Katherine A Roberts, Tatiana Trejos, Ruthmara Corzo, Jose R Almirall, Alan M Safer
This study applies Raman microspectroscopy to differentiate the chemical components in printing inks of different brands, colors, and type using the 532 nm and 785 nm excitation wavelengths. Spectra were collected from 319 inks (78 inkjet, 76 toner, 79 offset, and 86 intaglio) representing various colors. Comparisons were performed to calculate discrimination capability percentages for each ink type. Overall, Raman microspectroscopy differentiates according to the following hierarchy: intaglio (96%), inkjet (92%), offset (90%), and toner (61%)...
May 24, 2017: Journal of Forensic Sciences
https://www.readbyqxmd.com/read/28541929/pressure-induced-structural-modifications-of-rare-earth-hafnate-pyrochlore
#5
Katlyn M Turner, Dylan R Rittman, Rachel A Heymach, Cameron L Tracy, Madison L Turner, Antonio F Fuentes, Wendy L Mao, Rodney C Ewing
Complex oxides with the pyrochlore (A2B2O7) and defect-fluorite ((A,B)4O7) structure-types undergo structural transformations under high-pressure. Rare-earth hafnates (A2Hf2O7) form the pyrochlore structure for A  =  La-Tb and the defect-fluorite structure for A  =  Dy-Lu. High-pressure transformations in A2Hf2O7 pyrochlore (A  =  Sm, Eu, Gd) and defect-fluorite (A  =  Dy, Y, Yb) were investigated up to ~50 GPa and characterized by in situ Raman spectroscopy and synchrotron x-ray diffraction (XRD)...
May 25, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/28541703/molecular-origin-of-the-vibrational-structure-of-ice-ih
#6
Daniel R Moberg, Shelby C Straight, Christopher Knight, Francesco Paesani
An unambiguous assignment of the vibrational spectra of ice Ih remains a matter of debate. This study demonstrates that an accurate representation of many-body interactions between water molecules, combined with an explicit treatment of nuclear quantum effects through many-body molecular dynamics (MB-MD), leads to a unified interpretation of the vibrational spectra of ice Ih in terms of the structure and dynamics of the underlying hydrogen-bond network. All features of the infrared and Raman spectra in the OH stretching region can be unambiguously assigned by taking into account both the symmetry and the delocalized nature of the lattice vibrations as well as the local electrostatic environment experienced by each water molecule within the crystal...
May 26, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28541039/label-free-discrimination-of-rhizobial-bacteroids-and-mutants-by-single-cell-raman-microspectroscopy
#7
Jiabao Xu, Isabel Webb, Philip Poole, Wei E Huang
Symbiotic rhizobia in legume account for a large portion of nitrogen fixation in the biosphere. Nitrogen fixation is an energy-demanding process requiring tight control of metabolism and redox state. It is of great interest to understand the bacteroid differentiation process and the roles of energy storage molecules, such as glycogen and polyhydroxybutyrate (PHB), in maintaining the Rhizobium-legume symbioses. Traditional biochemical assays for checking phenotypic changes of mutants require a large volume of starting materials, which is difficult for unculturable, terminally differentiated bacteroids...
May 25, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28541036/non-invasive-diagnosis-of-high-grade-urothelial-carcinoma-in-urine-by-raman-spectral-imaging
#8
Hesham K Yosef, Sascha D Krauß, Tatjana Lechtonen, Hendrik Jütte, Andrea Tannapfel, Heiko Udo Käfferlein, Thomas Brüning, Florian Roghmann, Joachim Noldus, Axel Mosig, Samir F El-Mashtoly, Klaus Gerwert
The current gold standard for diagnosis of bladder cancer is cystoscopy, which is an invasive and painful for patients. Therefore, the non-invasive urine cytology is usually used in clinics as an adjunct to cystoscopy. However, it suffers from low sensitivity. Here, a novel non-invasive, label-free approach on urine is presented with high sensitivity. CARS imaging of urine sediments was used in the first step for fast preselection of urothelial cells, where, the high-grade urothelial cancer cells are characterized by a large nucleus to cytoplasm ratio...
May 25, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28541032/exosome-classification-by-pattern-analysis-of-surface-enhanced-raman-spectroscopy-data-for-lung-cancer-diagnosis
#9
Jaena Park, Miyeon Hwang, ByeongHyeon Choi, Hyesun Jeong, Jik-Han Jung, Hyun Koo Kim, Sunghoi Hong, Ji Ho Park, Yeonho Choi
Owing to the role of exosome as a cargo for intercellular communication, especially in cancer metastasis, the evidence has been consistently accumulated that exosomes can be used as a non-invasive indicator of cancer. Consequently, several studies applying exosome have been proposed for cancer diagnostic methods such as ELISA assay. However, it has been still challenging to get reliable results due to the requirement of a labeling process and high concentration of exosome. Here, we demonstrate a label-free and highly sensitive classification method of exosome by combining surface enhanced Raman scattering (SERS) and statistical pattern analysis...
May 25, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28538102/effects-of-wet-blending-on-detection-of-melamine-in-spray-dried-lactose
#10
Betsy Jean Yakes, Marti M Bergana, Peter F Scholl, Magdi M Mossoba, Sanjeewa R Karunathilaka, Luke K Ackerman, Jason D Holton, Boyan Gao, Jeffrey C Moore
During the development of rapid screening methods to detect economic adulteration, spray-dried milk powders prepared by dissolving melamine in liquid milk exhibited an unexpected loss of characteristic melamine features in the NIR and Raman spectra. To further characterize this "wet-blending" phenomenon, spray-dried melamine and lactose samples were produced as a simplified model and investigated by near-infrared spectroscopy, Raman spectroscopy, 1H NMR, and DART-FTMS. In contrast to dry-blended samples, characteristic melamine bands in NIR and Raman spectra disappeared or shifted in wet-blended lactose-melamine samples...
May 24, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28537611/metal-nanoinks-as-chemically-stable-surface-enhanced-scattering-sers-probes-for-the-analysis-of-blue-bic-ballpoint-pens
#11
A Alyami, D Saviello, M A P McAuliffe, A Mirabile, L Lewis, D Iacopino
Metal nanoinks constituted by Ag nanoparticles and Au nanorods were employed as probes for the Surface Enhanced Raman Scattering (SERS) analysis of a blue BIC ballpoint pen. The dye components of the pen ink were first separated by thin layer chromatography (TLC) and subsequently analysed by SERS at illumination wavelengths of 514 nm and 785 nm. Compared to normal Raman conditions, enhanced spectra were obtained for all separated spots, allowing easy identification of phthalocyanine Blue 38 and triarylene crystal violet in the ink mixture...
May 24, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28537308/catalytically-active-ceria-supported-cobalt-manganese-oxide-nanocatalysts-for-oxidation-of-carbon-monoxide
#12
Xu Wang, Lin-Ying Du, Meng Du, Chao Ma, Jie Zeng, Chun-Jiang Jia, Rui Si
A low-concentration cobalt (∼6 at%) and manganese (∼3 at%) bimetallic oxide catalyst supported on ceria nanorods (CoMnOx/CeO2), as well as its related single metal oxide counterparts (CoOx/CeO2 and MnOx/CeO2) was synthesized via a deposition-precipitation approach. The fresh samples after air-calcination at 400 °C were tested under the reaction conditions of CO oxidation, and showed the following order of reactivity: CoMnOx/CeO2 > CoOx/CeO2 > MnOx/CeO2. X-ray diffraction (XRD) and transmission electron microscopy (TEM) data identified that the structure of the CeO2 support was maintained during deposition of metal (Co, Mn) ions while the corresponding vis-Raman spectra verified that more oxygen vacancies were created after deposition-precipitation than those in pure ceria nanorods...
May 24, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28537217/effect-of-the-sulphur-atom-on-geometry-and-spectra-of-the-biomolecule-2-thiouracil-and-in-the-wc-base-pair-2-thiouridine-adenosine-influence-of-water-in-the-first-hydration-shell
#13
M Alcolea Palafox, V K Rastogi, S P Singh
The effect of the sulphur atom on 2-thiouracil (2TU) and 2-thiouridine molecules, as compared with uracil and uridine molecules, respectively, was carried out in several environments. The predicted IR spectrum of 2TU in the isolated state was compared with that obtained for uracil molecule and with those reported experimentally in matrix isolation. Its crystal unit cell in the solid state was simulated through a tetramer form using DFT methods for the first time. The calculated Raman spectrum was compared to the experimental ones in the solid state...
May 24, 2017: Journal of Biomolecular Structure & Dynamics
https://www.readbyqxmd.com/read/28534636/annealing-induced-shape-transformation-of-czts-nanorods-based-thin-films
#14
Govind Rajesh, Natarajan Muthukumarasamy, Dhayalan Velauthapillai, Sudip Kumar K Batabyal
Here we studied the annealing induced shape transformation of 1-D Cu2ZnSnS4 (CZTS) nanorods from nanospheres and nanocubes by simple sol-gel method without using any toxic chemicals or complicated vacuum based technology. X-ray diffraction pattern and Raman Spectra reveals the formation of Kesterite structure CZTS thin films. The energy dispersive X-ray analysis results indicate the presence of Cu, Zn, Sn and S. The elemental distribution of all the CZTS samples was studied using elemental mapping. The Hall effect studies of the CZTS thin film composed of nanorods exhibits the lowest resistivity values which indicates efficient charge transfer for unidirectional structure...
May 23, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28533478/real-time-near-infrared-raman-spectroscopy-for-the-diagnosis-of-nasopharyngeal-cancer
#15
Lim Chwee Ming, Nagaraja Rao Gangodu, Thomas Loh, Wei Zheng, Jianfeng Wang, Kan Lin, Huang Zhiwei
Near-infrared (NIR) Raman spectroscopy has been investigated as a tool to differentiate nasopharyngeal cancer (NPC) from normal nasopharyngeal tissue in an ex-vivo setting. Recently, we have miniaturized the fiber-optic Raman probe to investigate its utility in real time in-vivo surveillance of NPC patients. A posterior probability model using partial linear square (PLS) mathematical technique was constructed to verify the sensitivity and specificity of Raman spectroscopy in diagnosing NPC from post-irradiated and normal tissue using a diagnostic algorithm from three significant latent variables...
May 8, 2017: Oncotarget
https://www.readbyqxmd.com/read/28532130/effect-of-systematic-control-of-pd-thickness-and-annealing-temperature-on-the-fabrication-and-evolution-of-palladium-nanostructures-on-si-111-via-the-solid-state-dewetting
#16
Sundar Kunwar, Puran Pandey, Mao Sui, Quanzhen Zhang, Ming-Yu Li, Jihoon Lee
Si-based optoelectronic devices embedded with metallic nanoparticles (NPs) have demonstrated the NP shape, size, spacing, and crystallinity dependent on light absorption and emission induced by the localized surface plasmon resonance. In this work, we demonstrate various sizes and configurations of palladium (Pd) nanostructures on Si (111) by the systematic thermal annealing with the variation of Pd thickness and annealing temperature. The evolution of Pd nanostructures are systematically controlled by the dewetting of thin film by means of the surface diffusion in conjunction with the surface and interface energy minimization and Volmer-Weber growth model...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28530804/characterization-of-growth-patterns-of-nanoscale-organic-films-on-carbon-electrodes-by-surface-enhanced-raman-spectroscopy
#17
Mustafa Supur, Scott R Smith, Richard L McCreery
Electrochemical deposition of aromatic organic molecules by reduction of diazonium reagents enables formation of molecular layers with sufficient integrity for use in molecular electronic junctions of interest to microelectronics. Characterization of organic films with thicknesses in the 1-10 nm range is difficult with Raman spectroscopy, since most molecular structures of electronic interest have Raman cross sections which are too small to observe as either thin films on solid electrodes or within intact molecular junctions...
May 22, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28530790/polypyrrole-graphene-polyaniline-ternary-nanocomposite-with-high-thermoelectric-power-factor
#18
Yihan Wang, Jie Yang, Lingyu Wang, Kai Du, Qiang Yin, QinJian Yin
Polypyrrole/Graphene/Polyaniline (PPy/GNs/PANi) ternary nanocomposite with high thermoelectric power factor has been successfully prepared through the combination of in situ polymerization and solution process. FTIR, Raman spectra, XRD and SEM analyses show the strong π-π interactions existed among PPy, GNs and PANi, leading to the formation of more ordered regions in the composite. Both the in situ polymerization and solution process can enhance the dispersion homogeneity of graphene in the polymer matrix, bringing about increased nano-interfaces in the PPy/GNs/PANi composite...
May 22, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28528552/universal-selective-dispersion-of-semiconducting-carbon-nanotubes-from-commercial-sources-using-a-supramolecular-polymer
#19
Alex Chortos, Igor Pochorovski, Pei Lin, Gregory Pitner, Xuzhou Yan, Theodore Z Gao, John W F To, Ting Lei, John W Will, H-S Philip Wong, Zhenan Bao
Selective extraction of semiconducting carbon nanotubes is a key step in the production of high-performance, solution-processed electronics. Here we describe the ability of a supramolecular sorting polymer to selectively disperse semiconducting carbon nanotubes from five commercial sources with diameters ranging from 0.7 nm to 2.2 nm. The sorting purity of the largest diameter nanotubes (1.4 nm to 2.2 nm; from Tuball) was confirmed by short channel measurements to be 97.5%. Removing the sorting polymer by acid-induced disassembly increased the transistor mobility by 94% and 24% for medium-diameter and large-diameter carbon nanotubes, respectively...
May 21, 2017: ACS Nano
https://www.readbyqxmd.com/read/28528253/pressure-induced-transformations-in-sorbic-acid
#20
G D Saraiva, J R Maia, J A Lima, C E S Nogueira, P T C Freire, F F de Sousa, A M R Teixeira, J Mendes Filho
This research reports a pressure dependent Raman study of the sorbic acid between 0.0 and 10.0GPa. The unpolarized Raman spectra were measured in the spectral range of 20-3000cm(-1). The high-pressure Raman scattering study of the sorbic acid showed that it underwent a gradual, disordering process. At the room temperature and at the ambient pressure conditions, the crystal structure of the sorbic acid belongs to the monoclinic system with a C2/c (C2h(6)) space group. The pressure increase induced a higher disorder in the monoclinic unit cell, since a single bending mode, and only very broad stretching Raman modes are present at pressure of ~10GPa...
May 10, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
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