keyword
MENU ▼
Read by QxMD icon Read
search

Raman spectroscopy

keyword
https://www.readbyqxmd.com/read/28319939/radical-scavenging-activity-of-a-sunscreen-enriched-by-antioxidants-providing-protection-in-the-whole-solar-spectral-range
#1
Carla Souza, Patrícia Maia Campos, Sabine Schanzer, Stephanie Albrecht, Silke B Lohan, Jürgen Lademann, Maxim E Darvin, Martina C Meinke
BACKGROUND/AIM: The main reason for extrinsic skin aging is the negative action of free radicals. The formation of free radicals in the skin has been associated with ultraviolet (UV) exposure and also to visible (VIS) and near-infrared (NIR) irradiations. The aim of the present study was to evaluate the efficacy of a sunscreen in the whole solar range. METHODS: The radical-scavenging activity of a sunscreen in the UV, VIS, and NIR ranges was evaluated using electron paramagnetic resonance spectroscopy...
March 21, 2017: Skin Pharmacology and Physiology
https://www.readbyqxmd.com/read/28319904/sensitivity-enhancement-of-graphene-zinc-oxide-nanocomposite-based-electrochemical-impedance-genosensor-for-single-stranded-rna-detection
#2
Sze Shin Low, Hwei-San Loh, Jian Sheng Boey, Poi Sim Khiew, Wee Siong Chiu, Michelle T T Tan
An efficient electrochemical impedance genosensing platform has been constructed based on graphene/zinc oxide nanocomposite produced via a facile and green approach. Highly pristine graphene was synthesised from graphite through liquid phase sonication and then mixed with zinc acetate hexahydrate for the synthesis of graphene/zinc oxide nanocomposite by solvothermal growth. The as-synthesised graphene/zinc oxide nanocomposite was characterised with scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and X-ray diffractometry (XRD) to evaluate its morphology, crystallinity, composition and purity...
February 27, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28319386/determination-of-the-cu-iii-oh-bond-distance-by-resonance-raman-spectroscopy-using-a-normalized-version-of-badger-s-rule
#3
Andrew D Spaeth, Nicole L Gagnon, Debanjan Dhar, Gereon M Yee, William B Tolman
The stretching frequency, ν(Cu-O), of the [CuOH](2+) core in the complexes LCuOH (L = N,N'-bis(2,6-diisopropyl-4-R-phenyl)pyridine-2,6-dicarboxamide, R = H or NO2, or N,N'-bis(2,6-diisopropylphenyl)-1-methylpiperidine-2,6-dicarboxamide) was determined to be ∼630 cm(-1) by resonance Raman spectroscopy and verified by isotopic labeling. In efforts to use Badger's rule to estimate the bond distance corresponding to ν(Cu-O), a modified version of the rule was developed through use of stretching frequencies normalized by dividing by the appropriate reduced masses...
March 20, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28319361/block-copolymer-templated-hierarchical-porous-carbon-nanostructures-with-nitrogen-rich-functional-groups-for-molecular-sensing
#4
Ya-Sen Sun, Chien-Fu Lin, Shih-Ting Luo, Ching-Yuan Su
The self-assembly of a block copolymer offers access to micellar nanodomains with tunable dimensions and structural diversity through control of such molecular parameters as the volume fraction and molecular mass. We fabricated hierarchical porous carbon (HPC) nanostructures with bundles of aggregated nanospheres and with nitrogen-rich functional groups through pyrolysis of diblock copolymer micelles in multiple layers. The resultant HPC nanostructures with a considerable specific surface area serve as an excellent substrate for surface-enhanced Raman spectroscopy (SERS), coupled with fluorescence quenching, for molecular sensing of physically adsorbed Rhodamine 6G...
March 20, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28319037/monitoring-the-transformation-of-aliphatic-and-fullerene-molecules-by-high-energy-electrons-using-surface-enhanced-raman-spectroscopy
#5
Nassir Mojarad, Jean-Nicolas Tisserant, Hannes Beyer, Hao Dong, Patrick A Reissner, Yuriy Fedoryshyn, Andreas Stemmer
We report on using 100 keV electrons to obtain amorphous carbon from aliphatic and fullerene molecules, and study this process by monitoring their Raman signal. In this regard, we use self-assembled monolayers of gold nanoparticles to provide high electromagnetic field enhancement, which allows the detection of the Raman signal from even nanometer-thick layers of analyte. Our results show different dynamics in the amorphization process of the two molecules, although both show suppression of their original vibrational resonances even at low exposure doses...
March 20, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28315619/proton-conducting-system-imh2-2seo4%C3%A2-2h2o-investigated-with-vibrational-spectroscopy
#6
Sylwia Zięba, Adam Mizera, Katarzyna Pogorzelec-Glaser, Andrzej Łapiński
Imidazolium selenate dihydrate (ImH2)2SeO4·2H2O crystals have been investigated using Raman and IR spectroscopy. Experimental data were supported by the quantum-chemical calculations (DFT), Hirshfield surfaces and fingerprint plots analysis, and Bader theory calculations. The imidazolium selenate dihydrate crystal exhibits high proton conductivity of the order of ~10(-1)S/m at T=333K. The spectra of this compound are dominated by bands related to the lattice modes, the internal vibrations of the protonated imidazole cation, selenate anion, water molecules, and hydrogen bonds network...
February 28, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28314364/effect-of-ge-content-on-the-formation-of-ge-nanoclusters-in-magnetron-sputtered-gezrox-based-structures
#7
L Khomenkova, D Lehninger, O Kondratenko, S Ponomaryov, O Gudymenko, Z Tsybrii, V Yukhymchuk, V Kladko, J von Borany, J Heitmann
Ge-rich ZrO2 films, fabricated by confocal RF magnetron sputtering of pure Ge and ZrO2 targets in Ar plasma, were studied by multi-angle laser ellipsometry, Raman scattering, Auger electron spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction for varied deposition conditions and annealing treatments. It was found that as-deposited films are homogeneous for all Ge contents, thermal treatment stimulated a phase separation and a formation of crystalline Ge and ZrO2. The "start point" of this process is in the range of 640-700 °C depending on the Ge content...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28314363/raman-and-luminescent-spectra-of-sulfonated-zn-phthalocyanine-enhanced-by-gold-nanoparticles
#8
V Kavelin, O Fesenko, H Dubyna, C Vidal, T A Klar, C Hrelescu, L Dolgov
Sulfonated Zn phthalocyanine, as a prospective photosensitizer in the photodynamic therapy of tumors, is investigated by means of Raman, infrared, and fluorescence spectroscopies. Conventional and surface-enhanced spectra from this photosensitizer are obtained and compared. Gold nano-islands attached to silica cores (Au-SiO2) are proposed as nanostructures providing plasmonically enhanced signals. Pronounced enhancement of Raman and infrared spectral bands from sulfonated Zn phthalocyanine allows their more convenient assignment with vibrational modes of sulfonated Zn phthalocyanine...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28314146/novel-deep-eutectic-solvent-functionalized-carbon-nanotubes-adsorbent-for-mercury-removal-from-water
#9
Mohamed Khalid AlOmar, Mohammed Abdulhakim Alsaadi, Taha M Jassam, Shatirah Akib, Mohd Ali Hashim
Due to the interestingly tolerated physicochemical properties of deep eutectic solvents (DESs), they are currently in the process of becoming widely used in many fields of science. Herein, we present a novel Hg(2+) adsorbent that is based on carbon nanotubes (CNTs) functionalized by DESs. A DES formed from tetra-n-butyl ammonium bromide (TBAB) and glycerol (Gly) was used as a functionalization agent for CNTs. This novel adsorbent was characterized using Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, XRD, FESEM, EDX, BET surface area, and Zeta potential...
March 6, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28304304/raman-spectrometric-detection-methods-for-early-and-non-invasive-diagnosis-of%C3%A2-alzheimer-s-disease
#10
Chia-Chi Huang, Ciro Isidoro
The continuous increasing rate of patients suffering of Alzheimer's disease (AD) worldwide requires the adoption of novel techniques for non-invasive early diagnosis and monitoring of the disease. Here we review the various Raman spectroscopic techniques, including Fourier Transform-Raman spectroscopy, surface-enhanced Raman scattering spectroscopy, coherent anti-Stokes Raman scattering spectroscopy, and confocal Raman microspectroscopy, that could be used for the diagnosis of AD. These techniques have shown the potential to detect AD biomarkers, such as the amyloid-β peptide and the tau protein, or the neurotransmitters involved in the disease (e...
March 18, 2017: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/28304175/aligned-moo2-mos2-and-moo2-mote2-freestanding-core-shell-nanoplates-driven-by-surface-interactions
#11
Zachary Patrick Degregorio, Youngdong Yoo, James E Johns
Controlling the growth of two-dimensional (2D) transition metal dichalcogenides (TMDCs) is an important step to utilizing these materials for either electronics or catalysis. Here, we report a new surface-templated growth mechanism that enables the fabrication of MoO2/MoS2 and MoO2/MoTe2 core/shell nanoplates epitaxially aligned on (0001)-oriented 4H-silicon carbide and sapphire substrates. These heterostructures are characterized by a variety of techniques to identify the chemical and structural nature of the interface...
March 17, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28304057/topography-preserved-microwave-plasma-etching-for-top-down-layer-engineering-in-mos2-and-other-van-der-waals-materials
#12
Abin Varghese, Chithra H Sharma, Madhu Thalakulam
A generic and universal layer engineering strategy for van der Waals (vW) materials, scalable and compatible with the current semiconductor technology, is of paramount importance in realizing all-two-dimensional logic circuits and to move beyond the silicon scaling limit. In this letter, we demonstrate a scalable and highly controllable microwave plasma based layer engineering strategy for MoS2 and other vW materials. Using this technique we etch MoS2 flakes layer-by-layer starting from an arbitrary thickness and area down to the mono- or the few-layer limit...
March 17, 2017: Nanoscale
https://www.readbyqxmd.com/read/28304040/intermolecular-anharmonicity-in-molecular-crystals-interplay-between-experimental-low-frequency-dynamics-and-quantum-quasi-harmonic-simulations-of-solid-purine
#13
Michael T Ruggiero, J Axel Zeitler, Alessandro Erba
The intermolecular anharmonic potential of crystalline purine is probed by means of temperature-dependent terahertz time-domain spectroscopy, low-frequency Raman scattering, X-ray diffraction, and ab initio quasi-harmonic quantum-chemical simulations. As temperature increases, anharmonicity in the intermolecular interactions results in strongly anisotropic thermal expansion - with a negative thermal expansion along the b crystallographic axis - yielding corresponding bulk structural modifications. The observed thermally-induced shifts of most vibrational bands in the terahertz region of the spectra are shown to arise from volume-dependent thermal changes of the hydrogen-bond pattern along the a and b crystallographic axes...
March 17, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28303799/large-area-high-quality-monolayer-graphene-from-polystyrene-at-atmospheric-pressure
#14
Junqi Xu, Can Fu, Haibin Sun, Lanxiang Meng, Yanjie Xia, Chongwu Zhang, Xiaolei Yi, Wenchao Yang, Pengfei Guo, Chunlei Wang, Jiangfeng Liu
Graphene films have been attracting great interest owing to their unique physical properties. In this paper, we develop an efficient method to prepare large-area monolayer graphene (97.5% coverage) by atmospheric pressure chemical vapor deposition on Cu foils using polystyrene in a short time (3 min). Raman spectroscopy, transmission electron microscopy and scanning electron microscopy are employed to confirm the thickness and uniformity of the graphene films. Graphene films on glass substrates show high optical transmittance and electrical conductivity...
April 18, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28303044/fourier-transform-infrared-and-raman-spectroscopic-study-of-the-effect-of-the-thermal-treatment-and-extraction-methods-on-the-characteristics-of-ayocote-bean-starches
#15
Aurea Bernardino-Nicanor, Gerardo Acosta-García, Norma Güemes-Vera, José Luis Montañez-Soto, María de Los Ángeles Vivar-Vera, Leopoldo González-Cruz
Starches isolated from four ayocote bean varieties were modified by thermal treatment to determinate the effect of the treatment on the structural changes of ayocote bean starch. Scanning electron microscopy indicates that the starch granules have oval and round shapes, with heterogeneous sizes and fractures when the extraction method is used. The presence of new bands at 2850 and 1560 cm(-1) in the FT-IR spectra showed that the thermal treatment of ayocote beans induced an interaction between the protein or lipid and the amylose or amylopectin, while the sharpest band at 3400 cm(-1) indicated a dehydration process in the starch granule in addition to the presence of the band at 1260 cm(-1), indicating the product of the retrogradation process...
March 2017: Journal of Food Science and Technology
https://www.readbyqxmd.com/read/28301688/multiplex-single-cell-quantification-of-rare-rna-transcripts-from-protoplasts-in-a-model-plant-system
#16
Ulhas S Kadam, Burkhard Schulz, Joseph M K Irudayaraj
Here we demonstrate multiplex and simultaneous detection of four different rare RNA species from plant, Arabidopsis thaliana, using surface enhanced Raman spectroscopy and gold nanoprobes at single cell resolution. We show the applicability of nanoparticle-based Raman spectroscopic sensor to study intracellular RNA copies. First, we demonstrate that gold-nanoparticles decorate with Raman probes and carrying specific nucleic acid probe sequences can be uptaken by the protoplasts. We confirm the internalization of gold nanoprobes by TEM, ICP-MS, and fluorescence imaging...
March 16, 2017: Plant Journal: for Cell and Molecular Biology
https://www.readbyqxmd.com/read/28301331/electrical-and-photovoltaic-properties-of-residue-free-mos2-thin-films-by-liquid-exfoliation-method
#17
Seung Kyo Lee, Dongil Chu, Da Ye Song, Sang Woo Pak, Eun Kyu Kim
Molybdenum disulphide (MoS2) film fabricated by a liquid exfoliation method has a large potential on various applications because of its various advantages in mass production and low temperature process. In this study, residue-free MoS2 thin films were formed during the liquid exfoliation process and their electrical properties were characterized with interdigitated electrode. Then, MoS2 film thickness could be controlled by centrifuge condition in the range of 20~40 nm, and its carrier concentration and mobility were measured about 7...
March 16, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28300231/theoretical-and-experimental-examination-of-sfg-polarization-analysis-at-acetonitrile-water-solution-surfaces
#18
Kengo Saito, Qiling Peng, Lin Qiao, Lin Wang, Tatsuya Joutsuka, Tatsuya Ishiyama, Shen Ye, Akihiro Morita
Sum frequency generation (SFG) spectroscopy is widely used to observe molecular orientation at interfaces through a combination of various types of polarization. The present work thoroughly examines the relation between the polarization dependence of SFG signals and the molecular orientation, by comparing SFG measurements and molecular dynamics (MD) simulations of acetonitrile/water solutions. The present SFG experiment and MD simulations yield quite consistent results on the ratios of χ((2)) elements, supporting the reliability of both means...
March 16, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28299709/inkjet-printed-paper-fluidic-devices-for-onsite-detection-of-antibiotics-using-surface-enhanced-raman-spectroscopy
#19
Stephen M Restaino, Adam Berger, Ian M White
Surface enhanced Raman spectroscopy (SERS) provides rapid and sensitive identification of small molecule analytes. Traditionally, fabrication of SERS devices is an expensive process that involves the use of micro- and nano-fabrication procedures. Further, acquisition of diverse sample types requires complex preparation procedures that limits SERS to lab-based applications. Recent innovations using plasmonic nanoparticles embedded in flexible paper substrates has allowed the expansion of SERS techniques to portable analytical procedures...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28298144/enhanced-raman-spectroscopy-via-plasmonic-and-carbonaceous-nanostructures-for-the-detection-diagnosis-and-treatment-of-cancer-part-2-treatment
#20
Emilie Darrigues, Vijayalakshmi Dantuluri, Zeid A Nima, Kieng B Vang, Robert J Griffin, Alexandru R Biris, Anindya Ghosh, Alexandru S Biris
Raman spectroscopy and surface-enhanced Raman scattering (SERS) have the potential to improve the accurate treatment, detection, and monitoring of various diseases, particularly cancer. Over the last decade, technological developments have enhanced Raman spectroscopy's ability to detect, discriminate, and diagnose cancers, both with and without complex nanosystems. This review discusses the recent advances that have made Raman a major tool for tumor resection guidance, for drug delivery targeting and monitoring, and enhancing photodynamic and photothermal therapy with the support of carbon-based and/or noble metal plasmonic nanoparticles...
March 15, 2017: Drug Metabolism Reviews
keyword
keyword
108280
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"