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Secondary ion mass spectrometry

Louise Wogelred, Fredrik Höök, Björn Agnarsson, Peter Sjövall
Accurate detection and quantification of individual molecules is important for the development of improved diagnostic methods as well as biochemical characterization of disease progression and treatments. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a surface analysis technique capable of imaging the distribution of specific molecules on surfaces with a high spatial resolution (<1 μm) and high sensitivity. ToF-SIMS is particularly suitable for detection of molecules up to ∼2 kDa, including lipids, whereas larger molecules, such as peptides and proteins, are fragmented during analysis, which makes them difficult to identify...
March 15, 2018: Biointerphases
Nebile Isik, Elisabetta Maria Fiordaliso, Ray R LaPierre
Semiconductor nanowires (NWs) are a candidate technology for future optoelectronic devices. One of the critical issues in NWs is the control of impurity doping for the formation of p-n junctions. In this study, beryllium (p-type dopant) and tellurium (n-type dopant) in self-assisted GaAs NWs was studied. The GaAs NWs were grown on (111) Si by molecular beam epitaxy (MBE) using the self-assisted method. The dopant incorporation in the self-assisted GaAs NWs was investigated using Raman spectroscopy, photoluminescence, secondary ion mass spectrometry and electron holography...
March 15, 2018: Nanotechnology
Enrico Della Gaspera, Enrico Menin, Gianluigi Maggioni, Cinzia Sada, Alessandro Martucci
Sub-monolayers of monodisperse Au colloids with different surface coverage have been embedded in between two different metal oxide thin films, combining sol-gel depositions and proper substrates functionalization processes. The synthetized films were TiO₂, ZnO, and NiO. X-ray diffraction shows the crystallinity of all the oxides and verifies the nominal surface coverage of Au colloids. The surface plasmon resonance (SPR) of the metal nanoparticles is affected by both bottom and top oxides: in fact, the SPR peak of Au that is sandwiched between two different oxides is centered between the SPR frequencies of Au sub-monolayers covered with only one oxide, suggesting that Au colloids effectively lay in between the two oxide layers...
March 14, 2018: Materials
Tingting Fu, Nicolas Elie, Alain Brunelle
Wood extractives in the xylem of European larch Larix decidua were mapped by time-of-flight secondary ion mass spectrometry (TOF-SIMS) imaging, which allows the radial distribution of both mineral and lipophilic extractives in the xylem to be scrutinized with high spatial resolution for the first time. Results show that all the components are inhomogeneously distributed across the annual ring. Mineral nutrients including Na+ , K+ , Ca+ , and Cl- ions exhibit no preferential localization between earlywood and latewood, whereas PO3 - ion is exclusively present in the ray cells, indicating it may be related to acid phosphatase...
March 10, 2018: Phytochemistry
Basanth Babu Eedara, Bhamini Rangnekar, Colin Doyle, Alex Cavallaro, Shyamal C Das
Pharmacotherapy of tuberculosis is potentially more efficient when delivered by the inhaled route than by the current oral and/or parenteral routes due to the higher concentration of drug reaching the primary region of infection in the lungs. This study investigated the influence of the amino acid L-leucine alone and in combination with the phospholipid, 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC), on the aerosolization behaviour of the anti-TB drugs, pyrazinamide and moxifloxacin HCl. Spray dried powders of pyrazinamide (P), moxifloxacin (M) alone and in combination with 10% L-leucine (PL and ML) and 10% DPPC (PLD and MLD) were produced...
March 7, 2018: International Journal of Pharmaceutics
Thilo Rennert, Carmen Höschen, Derek Rogge, Markus Steffens
RATIONALE: In contaminated soil, Cu is commonly distributed among various very small particles. To enlighten the qualitative distribution of Cu in a contaminated Technosol (a soil developed from deposited technogenic material) on the sub-micron scale, we used nano-scale secondary ion mass spectrometry (NanoSIMS). METHODS: We studied seven areas (up to 40 μm × 40 μm) on a thin section of a soil horizon by NanoSIMS, measuring12 C- ,18 O- ,32 S- ,63 Cu- and56 Fe16 O- ...
March 10, 2018: Rapid Communications in Mass Spectrometry: RCM
Oliver Ciclet, Denis Barron, Steve Bajic, Jean-Luc Veuthey, Davy Guillarme, Alexandre Grand-Guillaume Perrenoud
The MS hyphenation performance of UniSpray®, a new design of atmospheric pressure ionization source was evaluated in both SFC and RPLC modes. Sensitivity, stability, versatility and matrix effects offered by the UniSpray were assessed in positive and negative ionization modes and systematically compared to an electrospray source (ESI) using 120 natural compounds covering an extended chemical space. In a first instance, a multivariate approach was used to screen and optimize the UniSpray source settings to maximize detection sensitivity...
March 5, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Małgorzata Jurak, Robert Mroczka, Rafał Łopucki
Lauryl gallate (LG) is an antioxidant agent. However, it exhibits poor solubility in water. Its interactions with the membrane result in structure evolution thus affecting the membrane functionality. In this paper the Brewster angle microscope coupled with the Langmuir trough was applied to determine the morphology, phase behaviour, thickness and miscibility of ternary Langmuir monolayers with equal mole fractions of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC); 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and an increasing mole fraction of LG...
March 7, 2018: Journal of Membrane Biology
Mai H Philipsen, Nhu N T Phan, John Stephen Fletcher, Per Malmberg, Andrew G Ewing
Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to study the effects of cocaine versus methylphenidate administration on both the localization and abundance of lipids in Drosophila melanogaster brain. A J105 ToF-SIMS with a 40 keV gas cluster primary ion source enabled us to probe molecular ions of biomolecules in the fly with a spatial resolution around 3 µm, giving us unique insights into the effect of these drugs on molecular lipids in the nervous system. Significant changes in phospholipid composition were observed in the central brain for both...
March 6, 2018: ACS Chemical Neuroscience
Claudia Tominski, Tina Lösekann-Behrens, Alexander Ruecker, Nikolas Hagemann, Sara Kleindienst, Carsten W Mueller, Carmen Höschen, Ingrid Kögel-Knabner, Andreas Kappler, Sebastian Behrens
The enrichment culture KS is one of the few existing autotrophic, nitrate-reducing Fe(II)-oxidizing cultures that can be continuously transferred without an organic carbon source. We used a combination of Catalyzed Amplification Reporter Deposition Fluorescence In-Situ Hybridization (CARD-FISH) and Nanoscale Secondary Ion Mass Spectrometry (NanoSIMS) to analyze community dynamics, single-cell activities and interactions among the two most abundant microbial community members ( i.e , Gallionellaceae sp. and Bradyrhizobium spp...
March 2, 2018: Applied and Environmental Microbiology
Marcel Heeger, Bonnie J Tyler, Martin Körsgen, Heinrich F Arlinghaus
In this study, the influence of two different cluster primary ions in laser secondary neutral mass spectrometry (Laser-SNMS) has been investigated. Despite the many advantages of Laser-SNMS, fragmentation of neutral organic molecules during both sputtering and photoionization has limited its efficiency for the study of large organic and biological molecules. Cluster ion sputtering, and in particular large argon gas cluster sputtering, has been proposed as a means of reducing this fragmentation. Molecules of 9-fluorenylmethoxycarbonyl-pentafluoro-l-phenylalanine were sputtered using Bi3 + and Ar2000 + cluster primary ions, and the desorbed neutral species ("secondary neutrals") were postionized using a 7...
March 2, 2018: Biointerphases
Arne Buchter, Johannes Hoffmann, Alexandra Delvallée, Enrico Brinciotti, Dimitri Hapiuk, Christophe Licitra, Kevin Louarn, Alexandre Arnoult, Guilhem Almuneau, François Piquemal, Markus Zeier, Ferry Kienberger
A calibration algorithm based on one-port vector network analyzer (VNA) calibration for scanning microwave microscopes (SMMs) is presented and used to extract quantitative carrier densities from a semiconducting n-doped GaAs multilayer sample. This robust and versatile algorithm is instrument and frequency independent, as we demonstrate by analyzing experimental data from two different, cantilever- and tuning fork-based, microscope setups operating in a wide frequency range up to 27.5 GHz. To benchmark the SMM results, comparison with secondary ion mass spectrometry is undertaken...
February 2018: Review of Scientific Instruments
Hyun Kyong Shon, Shin Hye Kim, Sohee Yoon, Chan Young Shin, Tae Geol Lee
Brain imaging using time-of-flight secondary ion mass spectrometry (ToF-SIMS) has been reported to produce the distorted biomolecular distributions due to the cholesterol-induced matrix effect when cholesterol migrates to the surface, particularly in white matter, which contains a high level of cholesterol. Frozen-hydrated analysis has been used to inhibit the movement of cholesterol in the brain. In this paper, the authors propose new sample preparation and drying methods that can be used to obtain accurate biomolecular images at room temperature, instead of frozen-hydrated analysis using liquid-nitrogen, which must be continuously supplied to maintain the sample at -160 °C during the experiment...
March 1, 2018: Biointerphases
Nicholas Winograd
Gas cluster ion beams (GCIBs) provide new opportunities for bioimaging and molecular depth profiling with secondary ion mass spectrometry (SIMS). These beams, consisting of clusters containing thousands of particles, initiate desorption of target molecules with high yield and minimal fragmentation. This review emphasizes the unique opportunities for implementing these sources, especially for bioimaging applications. Theoretical aspects of the cluster ion/solid interaction are developed to maximize conditions for successful mass spectrometry...
February 28, 2018: Annual Review of Analytical Chemistry
Zhigang Yin, Yuehua Hu, Wei Sun, Chenyang Zhang, Jianyong He, Zhijie Xu, Jingxiang Zou, Changping Guan, Chen Hu Zhang, Qingjun Guan, Shangyong Lin
In the present study, a novel compound 4-Amino-5-mercapto-1,2,4-triazole was first synthesized and its selective adsorption mechanism on the surface of chalcopyrite was comprehensively investigated using UV-vis spectra, Zeta potential, Fourier Transform Infrared Spectroscopy(FTIR), X-ray Photoelectron Spectroscopy Measurements(XPS), and Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and first principle calculations. The experimental and computational results consistently demonstrated that AMT would chemisorb onto the chalcopyrite surface by the formation of a five-membered chelate ring...
February 28, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Gustavo Ferraz Trindade, Marie-Laure Abel, Chris Lowe, Rene Tshulu, John F Watts
This work presents a data analysis extension to a well-established methodology for the assessment of organic coatings using imaging time-of-flight secondary ion mass spectrometry (ToF-SIMS). Such an approach produced results that can be analysed using a multivariate analysis (MVA) procedure that performs the simultaneous processing of spatially and chemically related datasets. The coatings consist of two commercial resins that yield extremely similar spectra and there are no peaks of sufficient intensity that are uniquely diagnostic of either material to provide an unambiguous identification of each...
February 28, 2018: Analytical Chemistry
Corryn E Chini, Gregory L Fisher, Ben Johnson, Michael M Tamkun, Mary L Kraft
Advances in three-dimensional secondary ion mass spectrometry (SIMS) imaging have enabled visualizing the subcellular distributions of various lipid species within individual cells. However, the difficulty of locating organelles using SIMS limits efforts to study their lipid compositions. Here, the authors have assessed whether endoplasmic reticulum (ER)-Tracker Blue White DPX® , which is a commercially available stain for visualizing the endoplasmic reticulum using fluorescence microscopy, produces distinctive ions that can be used to locate the endoplasmic reticulum using SIMS...
February 26, 2018: Biointerphases
Alexander J Kim, Sankha Basu, Carolyn Glass, Edgar L Ross, Nathalie Agar, Qing He, David Calligaris
Opioids are often used for analgesia via continuous intrathecal delivery by implantable devices. Higher concentration and daily dose of opioid have been postulated as risk factors for intrathecal granuloma formation. We present a 42-year-old female patient with chronic abdominal pain from refractory pancreatitis, with an intrathecal drug delivery device implanted 21 years prior, delivering continuous intrathecal morphine. After many years without concerning physical signs or complaint, with gradual increases in daily morphine dose, she presented with rapidly progressive neurologic deficits, including lower extremity, bladder, and bowel symptoms...
February 26, 2018: Pain Practice: the Official Journal of World Institute of Pain
R Havelund, M P Seah, M Tiddia, I S Gilmore
A procedure has been established to define the interface position in depth profiles accurately when using secondary ion mass spectrometry and the negative secondary ions. The interface position varies strongly with the extent of the matrix effect and so depends on the secondary ion measured. Intensity profiles have been measured at both fluorenylmethyloxycarbonyl-L-pentafluorophenylalanine (FMOC) to Irganox 1010 and Irganox 1010 to FMOC interfaces for many secondary ions. These profiles show separations of the two interfaces that vary over some 10 nm depending on the secondary ion selected...
February 21, 2018: Journal of the American Society for Mass Spectrometry
Lydia Pohl, Angelika Kölbl, Florian Werner, Carsten W Mueller, Carmen Höschen, Werner Häusler, Ingrid Kögel-Knabner
RATIONALE: Al-substituted goethite is ubiquitous in soils and sediments. The extent of Al substitution affects the physicochemical properties of the mineral and influences its macroscale properties. Bulk analysis only provides total Al/Fe ratios without providing information with respect to the Al-substitution of single minerals. Here, we demonstrate that Nanoscale secondary ion mass spectrometry (NanoSIMS) enables the precise determination of Al-content in single minerals, while simultaneously visualising the variation of the Al/Fe ratio...
February 21, 2018: Rapid Communications in Mass Spectrometry: RCM
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