Spectroscopy and Diffraction

Molecular level solid-, liquid- and gas-interactions can be investigated through structural, chemical and compositional analysis with remarkable atomic scale spatial and high-energy resolution spectrometers and diffractometers for novel fundamental research. See a complete list of Spectroscopy and Diffraction instruments.

Resources and Techniques

  • Electron spectroscopy
  • Electron backscatter diffraction
  • Atom probe tomography
  • Ion/molecular beam spectroscopy
  • 57Fe-Mössbauer spectroscopy
  • Optical spectroscopy
  • X-ray tomography and diffractometers

Additional Information:

Description

Capability Details

  • Electron spectrometers with high spatial and energy resolution in-situ and ex-situ x-ray photoelectron spectroscopy
  • Secondary ion mass spectrometers with single and cluster ion sources, and time-of-flight and magnetic mass analyzers
  • Electron microscopes with energy dispersive X-ray spectroscopy, electron energy loss spectroscopy and electron backscatter diffraction
  • Local Electrode Atom Probe tomography system with 355 nm UV laser and reflectron flight path for high mass resolution
  • Fourier transform infrared spectrometers with vacuum bench and variable temperature capability
  • Confocal-Raman, cryogenic time-resolved fluorescence, circular dichroism, stopped-flow absorbance, laser-induced breakdown and sum frequency generation optical tools
  • Variable temperature Mössbauer spectroscopy systems for bulk (transmission mode) and surface (emission) measures
  • X-ray diffraction instruments with sealed tube or rotating anode for analysis of powder, thin film and single crystal samples; point, CCD and image plate detection. X-ray computed tomography with 225- and 320-kV fixed, and 225-kV rotating target options using a 2000x2000 pixel area detector and state-of-the-art processing and visualization software

Electron spectroscopy – Achieving nanoscale spatial resolution, users can study elemental composition, structural properties, and chemical states of materials with applications to thin films, nanomaterials, catalysis, biological and environmental sciences, corrosion, and atmospheric aerosols.

Electron backscatter diffraction – Samples of microstructures in environmental and material science can be examined with three dimensional reconstruction and characterization using focused ion beam-electron backscatter diffraction analysis.

Atom probe tomography – Atom Probe Tomography (APT) provides comprehensive and accurate three dimensional chemical imaging for characterization of both metallic materials and low electrical conductivity materials, such as semiconductors, oxides, carbides, nitrides and composites.

Ion/molecular beam spectroscopy – Secondary ions and scattered ions from various materials are analyzed in straight, magnetic or time-of-flight mass spectrometers to investigate elemental, isotopic and molecular compositions through surface spectra, one dimensional depth profiling and two dimensional and three dimensional chemical imaging.

57Fe-Mössbauer spectroscopy – Using 57Fe (a versatile, highly sensitive, and stable isotope with natural abundance of 2.2%), users can obtain information about the valence state, coordination number and magnetic ordering temperatures for a wide range of Fe-containing samples; (e.g., Fe-organic matter complexes, sediments, catalysts, glass materials).

Optical spectroscopy – Fluorimetry, stopped-flow absorbance, FTIR and confocal-Raman tools enable analysis for biology, radiochemistry, and catalysis. Sum frequency generation-vibrational spectroscopy and second harmonic generation are available to study liquid, liquid and solid, and liquid interfaces.

X-ray tomography and diffractometers – X-ray computed tomography delivers images of microstructures (components, pore structure and connectivity) in biological and geological samples at tens of microns spatial resolution. General purpose and specialized x-ray diffraction systems, including single-crystal, microbeam and variable temperature powder capabilities, empower phase analysis of polycrystalline, epitaxial thin films, protein structure determination, and studies of problematic small inorganic molecules.

Instruments

The Physical Electronics Instruments (PHI) Quantum 2000 X-ray photoelectron spectrometer (XPS) is a unique system that uses a focused monochromatic...
Custodian(s): Mark Engelhard
Recently built and only available at EMSL, this customized SFG-VS spectrometer employs the synchronization of a 100-picosecond amplifier laser,...
Custodian(s): Hongfei Wang, Mark Bowden
The X-ray photoelectron spectroscopy (XPS) imaging system provides fast, uantitative, real-time parallel imaging with highest resolution...
EMSL offers a suite of instrumentation dedicated to understanding photoreactivity in the condensed phase, on surfaces, and at material interfaces....
Custodian(s): , Alan G Joly
EMSL offers a suite of instrumentation dedicated to understanding photoreactivity in the condensed phase, on surfaces, and at material interfaces....
Custodian(s): , Alan G Joly

Publications

Ferrocene (Fc) and N-(ferrocenylmethyl)-N,N-dimethyl-N-ethylammonium bistrifluoromethyl-sulfonimide (Fc1N112-TFSI) were dissolved in carbonate...
Many experimental and theoretical studies have established the specific anion, as well as cation effects on the hydrogen-bond structures at the air/...
The photochemical properties of nitric oxide on a mixed oxide single crystal surface was examined in ultrahigh vacuum (UHV) using temperature...
Here we describe an ultrasensitive electrochemical nucleic acids assay amplified by carbon nanotubes (CNTs)-based labels for the detection of human...
Removal of highly abundant proteins in plasma is often carried out using immunoaffinity depletion to extend the dynamic range of measurements to...

Science Highlights

Posted: January 13, 2015
The Science Lithium (Li) metal has long been considered one of the most attractive anode materials, but large-scale application of high-energy...
Posted: November 21, 2014
The Science Carbon dioxide (CO2) sequestration in deep subsurface environments has received significant attention and investment as a way to reduce...
Posted: October 17, 2014
A multi-institutional team of researchers studied how and when cloud ice crystals form. Dust is usually a primary catalyst encouraging ice formation...
Posted: September 12, 2014
Green fluorescent proteins, or GFPs, are found in jellyfish and other marine animals and glow green when exposed to light. Scientists use GFPs use...
Posted: June 17, 2014
The Science Hexavalent chromium is a major environmental contaminant at several Department of Energy (DOE) sites as well as other sites around the...

Molecular level solid-, liquid- and gas-interactions can be investigated through structural, chemical and compositional analysis with remarkable atomic scale spatial and high-energy resolution spectrometers and diffractometers for novel fundamental research. See a complete list of Spectroscopy and Diffraction instruments.

Resources and Techniques

  • Electron spectroscopy
  • Electron backscatter diffraction
  • Atom probe tomography
  • Ion/molecular beam spectroscopy
  • 57Fe-Mössbauer spectroscopy
  • Optical spectroscopy
  • X-ray tomography and diffractometers

Additional Information:

Attachments: 

Influence of Adsorption Site and Wavelength on the Photodesorption of NO from the (Fe,Cr)3O4(111) Mixed Oxide Surface.

Abstract: 

The photochemical properties of nitric oxide on a mixed oxide single crystal surface was examined in ultrahigh vacuum (UHV) using temperature programmed desorption (TPD), photon stimulated desorption (PSD) and low energy electron diffraction (LEED). The mixed oxide was a 75% Fe and 25% Cr corundum (0001) oxide film prepared on an -Al2O3(0001) crystal, however its surface became terminated with a magnetite-like (111) structure after sputter/anneal cleaning, leading to a surface designated of (Fe,Cr)3O4(111). TPD of NO from the (Fe,Cr)3O4(111) surface revealed three chemisorbed states at 220, ~315 and 370 K assigned to NO binding at Fe3+, Cr3+ and Fe2+ sites, respectively. No significant thermal chemistry of NO was detected. NO photodesorption, the primary photochemical pathway in UHV, was sensitive to the adsorption site, with rates at the three adsorption sites following the trend: Fe3+ > Fe2+ > Cr3+. Multiexponential rate behavior seen in the overall NO PSD spectra was linked directly to site heterogeneity being manifested as a convolution of the individual NO photodesorption rates at the three types of surface sites. The photodesorption rate with UV light (365 nm) was ~10 times greater than that in the visible, but the per-photon rates across the visible spectrum (from 460 to 630 nm) were independent of the wavelength, which is suggestive of localized photon absorption at the adsorption site. Results in this study demonstrate that the adsorption site plays a critical role in determining photochemical rates on complex oxide surfaces. This work was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multi-program national laboratory operated for DOE by Battelle. The research was performed using EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory.

Citation: 
Henderson MA.2014."Influence of Adsorption Site and Wavelength on the Photodesorption of NO from the (Fe,Cr)3O4(111) Mixed Oxide Surface."Journal of Physical Chemistry C 118(36):21021-21030. doi:10.1021/jp506602x
Authors: 
MA Henderson
Facility: 
Volume: 
118
Issue: 
36
Pages: 
21021-21030
Publication year: 
2014

Reorientation of the ‘free OH’ group in the top-most layer of air/water interface of sodium fluoride aqueous

Abstract: 

Many experimental and theoretical studies have established the specific anion, as well as cation effects on the hydrogen-bond structures at the air/water interface of electrolyte solutions. However, the ion effects on the top-most layer of the air/water interface, which is signified by the non-hydrogen-bonded so-called ‘free O-H’ group, has not been discussed or studied. In this report, we present the measurement of changes of the orientational angle of the ‘free O-H’ group at the air/water interface of the sodium fluoride (NaF) solutions at different concentrations using the interface selective sum-frequency generation vibrational spectroscopy (SFG-VS) in the ssp and ppp polarizations. The polarization dependent SFG-VS results show that the average tilt angle of the ‘free O-H’ changes from about 35.3 degrees ± 0.5 degrees to 43.4 degrees ± 2.1degrees as the NaF concentration increase from 0 to 0.94M (nearly saturated). Such tilt angle change is around the axis of the other O-H group of the same water molecule at the top-most layer at the air/water interface that is hydrogen-bonded to the water molecules below the top-most layer. These results provide quantitative molecular details of the ion effects of the NaF salt on the structure of the water molecules at the top-most layer of the air/water interfacial, even though both the Na+ cation and the F- anion are believed to be among the most excluded ions from the air/water interface.

Citation: 
Feng RR, Y Guo, and H Wang.2014."Reorientation of the ‘free OH’ group in the top-most layer of air/water interface of sodium fluoride aqueous solution probed with sum-frequency generation vibrational spectroscopy."Journal of Chemical Physics 141(18):18C507-1 to 18C507-10. doi:10.1063/1.4895561
Authors: 
RR Feng
Y Guo
H Wang
Volume: 
0
Issue: 
0
Pages: 
0
Publication year: 
2014

Diffusional Motion of Redox Centers in Carbonate Electrolytes .

Abstract: 

Ferrocene (Fc) and N-(ferrocenylmethyl)-N,N-dimethyl-N-ethylammonium bistrifluoromethyl-sulfonimide (Fc1N112-TFSI) were dissolved in carbonate solvents and self diffusion coefficents (D) of solutes and solvents were measured by 1H and 19F pulsed field gradient (PFG) nuclear magnetic resonance (NMR) spectroscopy. The organic solvents were propylene carbonate (PC), ethyl methyl carbonate (EMC) and a ternary mixture that also includes ethylene carbonate (EC). Results from NMR studies over the temperature range of 0-50 °C and for various concentrations (0.25 - 1.7 M) of Fc1N112-TFSI are compared to values of D simulated with classical molecular dynamics (MD). The measured self-diffusion coefficients gradually decreased as the Fc1N112-TFSI concentration increased in all solvents. Since the peaks for the two ions (Fc1N212 and TFSI) are separated in one-dimensional NMR spectra, separate diffusion coefficients could be measured and DTFSI is larger than DFc1N112 in all samples measured. The EC, PC and EMC have the same D in the neat solvent mixture and when Fc is dissolved in EC/PC/EMC at a concentration of 0.2 M, probably due to the interactions between common carbonyl structures within EC, PC and EMC. A difference in D (DPC < DEC < DEMC), and both a higher Ea for translational motion and higher effective viscosity for PC in the mixture containing Fc1N112-TFSI reflect the interaction between PC and Fc1N112+, which is a relatively stronger interaction than that between Fc1N112+ and other solvent species. In the EC/PC/EMC solution that is saturated with Fc1N112-TFSI, we find that DPC = DEC = DEMC and Fc1N112+ and all components of the EC/PC/EMC solution have the same Ea for translational motion, while the ratio DEC/PC/EMC/DFc1N112+ is approximately 3. These results reflect the lack of available free volume for independent diffusion in the saturated solution. The Fc1N112+ transference numbers lie around 0.4 and increases slightly as the temperature is increased in the PC and EMC solvents. The trends observed for D from simulations are in good agreement with experimental results and provide molecular level understanding of the solvation structure of Fc1N112-TFSI dissolved in EC/PC/EMC.

Citation: 
Han KS, NN Rajput, X Wei, W Wang, JZ Hu, KA Persson, and KT Mueller.2014."Diffusional Motion of Redox Centers in Carbonate Electrolytes ."Journal of Chemical Physics 141(10):104509. doi:10.1063/1.4894481
Authors: 
KS Han
NN Rajput
X Wei
W Wang
JZ Hu
KA Persson
KT Mueller
Instruments: 
Volume: 
0
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0
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0
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2014

Low-Temperature Carbon Monoxide Oxidation Catalysed by Regenerable Atomically Dispersed Palladium on Alumina.

Abstract: 

Catalysis by single isolated atoms of precious metals has attracted much recent interest since it promises the ultimate economy in atom efficiency. Previous reports have been confined to reducible oxide supports such as FeOx, TiO2 or CeO2. Here we show that isolated Pd atoms can be stabilized on industrially relevant gamma-alumina supports. At low Pd loadings (≤0.5 wt%) these catalysts contain exclusively atomically dispersed Pd species. The addition of lanthanum-oxide to the alumina, long known for its ability to improve alumina stability, is found to also help in the stabilization of isolated Pd atoms. Aberration-corrected scanning transmission electron microscopy (AC-STEM) confirms the presence of intermingled Pd and La on the gamma-alumina surface. Operando X-ray absorption spectroscopy, performed on Pd/La-alumina and Pd/gamma-alumina (0.5 wt% Pd) demonstrates the presence of catalytically active atomically dispersed ionic Pd in the Pd/La-doped gamma-alumina system. CO oxidation reactivity measurements show onset of catalytic activity at 40 ˚C, indicating that the ionic Pd species are not poisoned by CO. The reaction order in CO and O2 is positive, suggesting a reaction mechanism that is different from that on metallic Pd. The catalyst activity is lost if the Pd species are reduced to their metallic form, but the activity can be regenerated by oxidation at 700 ˚C in air. The high-temperature stability of these ionic Pd species on commercial alumina supports makes this catalyst system of potential interest for low-temperature exhaust treatment catalysts.

Citation: 
Peterson E, A DelaRiva, S Lin, RS Johnson, H Guo, J Miller, JH Kwak, CHF Peden, B Kiefer, LF Allard, F Ribeiro, and AK Datye.2014."Low-Temperature Carbon Monoxide Oxidation Catalysed by Regenerable Atomically Dispersed Palladium on Alumina."Nature Communications 5:Article No. 4885. doi:10.1038/ncomms5885
Authors: 
E Peterson
A DelaRiva
S Lin
RS Johnson
H Guo
J Miller
JH Kwak
CHF Peden
B Kiefer
LF Allard
F Ribeiro
AK Datye
Volume: 
0
Issue: 
0
Pages: 
0
Publication year: 
2014

Effect of Solar Radiation on the Optical Properties and Molecular Composition of Laboratory Proxies of Atmospheric Brown Carbon

Abstract: 

Sources, optical properties, and chemical composition of atmospheric brown carbon (BrC) aerosol are uncertain, making it challenging to estimate its contribution to radiative forcing. Furthermore, optical properties of BrC may change significantly during its atmospheric aging. We examined the effect of solar photolysis on the molecular composition, mass absorption coefficient, and fluorescence of secondary organic aerosol prepared by high-NOx photooxidation of naphthalene (NAP SOA). The aqueous solutions of NAP SOA was observed to photobleach with an effective half-time of 15 hours (with sun in its zenith) for the loss of the near-UV (300 -400 nm) absorbance. The molecular composition of NAP SOA was significantly modified by photolysis, with the average SOA formula changing from C14.1H14.5O5.1N0.08 to C11.8H14.9O4.5N0.02 after 4 hours of irradiation. The average O/C ratio did not change significantly, however, suggesting that it is not a good metric for assessing the extent of photolysis-driven aging in NAP SOA (and in BrC in general). In contrast to NAP SOA, the photolysis of BrC material produced by aqueous reaction of limonene+O3 SOA (LIM/O3 SOA) with ammonium sulfate was much faster, but it did not result in a significant change in the molecular level composition. The characteristic absorbance of the aged LIM/O3 SOA in the 450-600 nm range decayed with an effective half-time of <0.5 hour. This result emphasizes the highly variable and dynamic nature of different types of atmospheric BrC.

Citation: 
Lee HJ, PK Aiona, A Laskin, J Laskin, and S Nizkorodov.2014."Effect of Solar Radiation on the Optical Properties and Molecular Composition of Laboratory Proxies of Atmospheric Brown Carbon ."Environmental Science & Technology 48(17):10217-10226. doi:10.1021/es502515r
Authors: 
HJ Lee
PK Aiona
A Laskin
J Laskin
S Nizkorodov
Volume: 
48
Issue: 
17
Pages: 
10217-10226
Publication year: 
2014

Polysialylated N-Glycans Identified in Human Serum Through Combined Developments in Sample Preparation, Separations and

Abstract: 

The N-glycan diversity of human serum glycoproteins, i.e. the human blood serum N-glycome, is complex due to the range of glycan structures potentially synthesizable by human glycosylation enzymes. The reported glycome, however, is limited by methods of sample preparation, available analytical platforms, e.g., based upon electrospray ionization-mass spectrometry (ESI-MS), and software tools for data analysis. In this report, several improvements have been implemented in sample preparation and analysis to extend ESI-MS glycan characterization and to provide an improved view of glycan diversity. Sample preparation improvements include acidified, microwave-accelerated, PNGase F N-glycan release, and sodium borohydride reduction were optimized to improve quantitative yields and conserve the number of glycoforms detected. Two-stage desalting (during solid phase extraction and on the analytical column) increased the sensitivity by reducing analyte signal division between multiple reducing-end-forms or cation adducts. On-line separations were improved by using extended length graphitized carbon columns and adding TFA as an acid modifier to a formic acid/reversed phase gradient which provides additional resolving power and significantly improved desorption of both large and heavily sialylated glycans. To improve MS sensitivity and provide gentler ionization conditions at the source-MS interface, subambient pressure ionization with nanoelectrospray (SPIN) has been utilized. When method improvements are combined together with the Glycomics Quintavariate Informed Quantification (GlyQ-IQ) recently described1 these technologies demonstrate the ability to significantly extend glycan detection sensitivity and provide expanded glycan coverage. We demonstrate application of these advances in the context of the human serum glycome, and for which our initial observations include detection of a new class of heavily sialylated N-glycans, including polysialylated N-glycans.

Citation: 
Kronewitter SR, I Marginean, JT Cox, R Zhao, CD Hagler, AK Shukla, TS Carlson, JN Adkins, DG Camp, II, RJ Moore, KD Rodland, and RD Smith.2014."Polysialylated N-Glycans Identified in Human Serum Through Combined Developments in Sample Preparation, Separations and Electrospray ionization-mass spectrometry."Analytical Chemistry 86(17):8700-10. doi:10.1021/ac501839b
Authors: 
SR Kronewitter
I Marginean
JT Cox
R Zhao
CD Hagler
AK Shukla
TS Carlson
JN Adkins
DG Camp
II
RJ Moore
KD Rodl
RD Smith
Facility: 
Instruments: 
Volume: 
86
Issue: 
17
Pages: 
8700-10
Publication year: 
2014

Composition and Interface Analysis of InGaN/GaN Multiquantum-Wells on GaN Substrates Using Atom Probe Tomography.

Abstract: 

In0.20Ga0.80N/GaN multi-quantum wells grown on [0001]-oriented GaN substrates with and without an InGaN buffer layer were characterized using three-dimensional atom probe tomography. In all samples, the upper interfaces of the QWs were slightly more diffuse than the lower interfaces. The buffer layers did not affect the roughness of the interfaces within the quantum well structure, a result attributed to planarization of the surface of the 1st GaN barrier layer which had an average root-mean-square roughness of 0.177 nm. The In and Ga distributions within the MQWs followed the expected distributions for a random alloy with no indications of In clustering.

Citation: 
Liu F, L Huang, RF Davis, LM Porter, DK Schreiber, SVNT Kuchibhatla, V Shutthanandan, S Thevuthasan, E Preble, T Paskova, and KR Evans.2014."Composition and Interface Analysis of InGaN/GaN Multiquantum-Wells on GaN Substrates Using Atom Probe Tomography."Journal of Vacuum Science and Technology B--Microelectronics and Nanometer Structures 32(5):Article No. 051209. doi:10.1116/1.4893976
Authors: 
F Liu
L Huang
RF Davis
LM Porter
DK Schreiber
SVNT Kuchibhatla
V Shutthanan
S Thevuthasan
E Preble
T Paskova
KR Evans
Volume: 
0
Issue: 
0
Pages: 
0
Publication year: 
2014

Symmetries of migration related segments of all [001] coincidence site lattice tilt boundaries in (001) projections for all

Abstract: 

Utilizing bicrystallography in two dimensions (2D), the symmetries of migration related segments of Coincidence Site Lattice (CSL) boundaries are derived for projections along their [001] tilt axis in grain boundaries of crystalline materials that possess the holohedral point symmetry of the cubic system (i.e. m3m). These kinds of “edge-on” projections are typical for atomic resolution imaging of such tilt boundaries with Transmission Electron Microscopes (TEM). This fact facilitates the visual confirmation of our predictions by recently published Zcontrast scanning TEM investigations [H. Yang et al., Phil. Mag. 93 (2013) 1219] and many other TEM studies.

Citation: 
Moeck P, BW York, and ND Browning.2014."Symmetries of migration related segments of all [001] coincidence site lattice tilt boundaries in (001) projections for all holohedral cubic materials."Crystal Research & Technology 49(9):708-720. doi:10.1002/crat.201400071
Authors: 
P Moeck
BW York
ND Browning
Instruments: 
Volume: 
49
Issue: 
9
Pages: 
708-720
Publication year: 
2014

Micro-Spectroscopic Imaging and Characterization of Individually Identified Ice Nucleating Particles from a Case Field Study.

Abstract: 

The effect of anthropogenic and biogenic organic particles on atmospheric glaciation processes is poorly understood. We use an optical microscopy (OM) setup to identify the location of ice nuclei (IN) active in immersion freezing and deposition ice nucleation for temperatures of 200-273 K within a large population of particles sampled from an ambient environment. Applying multi-modal micro-spectroscopy methods we characterize the physicochemical properties of individual IN in particle populations collected in central California. Chemical composition and mixing state analysis of particle populations are performed to identify characteristic particle-type classes. All particle-types contained organic material. Particles in these samples take up water at subsaturated conditions, induce immersion freezing at subsaturated and saturated conditions above 226 K, and act as deposition IN below 226 K. The identified IN belong to the most common particle-type classes observed in the field samples: organic coated sea salt, Na-rich, and secondary and refractory carbonaceous particles. Based on these observations, we suggest that the IN are not always particles with unique chemical composition and exceptional ice nucleation propensity; rather, they are common particles in the ambient particle population. Thus, particle composition and morphology alone are insufficient to assess their potential to act as IN. The results suggest that particle-type abundance is also a crucial factor in determining the ice nucleation efficiency of specific IN types. These findings emphasize that ubiquitous organic particles can induce ice nucleation under atmospherically relevant conditions and that they may play an important role in atmospheric glaciation processes.

Citation: 
Knopf DA, PA Alpert, B Wang, RE O'Brien, ST Kelly, A Laskin, MK Gilles, and RC Moffet.2014."Micro-Spectroscopic Imaging and Characterization of Individually Identified Ice Nucleating Particles from a Case Field Study."Journal of Geophysical Research. D. (Atmospheres) 119(17):10,365-10,381. doi:10.1002/2014JD021866
Authors: 
DA Knopf
PA Alpert
B Wang
RE O'Brien
ST Kelly
A Laskin
MK Gilles
RC Moffet
Facility: 
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Volume: 
0
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0
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0
Publication year: 
2014

Behavior of nanoceria in biologically-relevant environments.

Abstract: 

Cerium oxide nanoparticles (CNPs) have gained a considerable attention in biological research due to their anti-oxidant like behaviour and regenerative nature. The current literature on CNPs reports many successful attempts on harnessing the beneficial therapeutic properties in biology. However studies have also shown toxicity effect with some types of CNPs. This review discusses issues associated with the behaviours of CNPs in biological systems and identifies key knowledge gaps. We explore how salient physicochemical properties (size, surface chemistry, surface stabilizers) contribute to the potential positive and negative aspects of nanoceria in biological systems. Based on variations of results reported in the literature, important issues need to be addressed. Are we really studying the same particles with slight variations in size and physicochemical properties or do the particles being examined have fundamentally different behaviours? Are the variations observed in the result of differences in the initial properties of the particles or the results of downstream effects that emerge as the particles are prepared for specific studies and they interact with biological or other environmental moieties? How should particles be appropriately prepared for relevant environmental/toxicology/safety studies? It is useful to recognize that nanoparticles encompass some of the same complexities and variability associated with biological components

Citation: 
Kumar A, S Das, P Munusamy, W Self, DR Baer, DC Sayle, and S Seal.2014."Behavior of nanoceria in biologically-relevant environments."Environmental Science: Nano 1(6):516-532. doi:10.1039/C4EN00052H
Authors: 
A Kumar
S Das
P Munusamy
W Self
DR Baer
DC Sayle
S Seal
Instruments: 
Volume: 
1
Issue: 
6
Pages: 
516-532
Publication year: 
2014

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