scholarly journals Chemical Separation on Silver Nanorods Surface Monitored by TOF-SIMS

2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
Ondrej Petruš ◽  
Andrej Oriňak ◽  
Renáta Oriňaková ◽  
Christian Muhmann ◽  
Ján Macko ◽  
...  
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Rhodamine 6G ◽  
Chemical Separation ◽  
Molecular Ions ◽  
Chemical Components ◽  
Sampling Point ◽  
Self Assembled Monolayer ◽  
Component Mixture ◽  
Silver Nanorods ◽  
Tof Sims

The article introduces a possible chemical separation of a mixture of two compounds on the metal nanorods surface. A silver nanorods surface has been prepared by controlled electrochemical deposition in anodic alumina oxide (AAO) template. Rhodamine 6G and 4-aminothiophenol have been directly applied to the sampling point on a silver nanorods surface in an aliquot mixture. The position of the resolved compounds was analysed by time-of-flight secondary ion mass spectrometry (TOF-SIMS) which measured the fragments and the molecular ions of the two compounds separated on the silver nanorods surface. Rhodamine 6G has been preconcentrated as 1.5 mm radial from the sampling point while 4-aminothiophenol formed a continuous self-assembled monolayer on the silver nanorods surface with a maximum molecular ion intensity at a distance of 0.5 mm from the sampling point. The separation of the single chemical components from the two-component mixture over the examined silver nanostructured films could clearly be shown. A fast separation on the mentioned nanotextured films was observed (within 50 s). This procedure can be easily integrated into the micro/nanofluidic systems or chips and different detection systems can be applied.

Primary ion fluence dependence in time-of-flight SIMS of a self-assembled monolayer of octadecylphosphonic acid molecules on mica discussion of static limit

2007 ◽  
Vol 85 (12) ◽  
pp. 1075-1082 ◽  
Author(s):  
M Nieradko ◽  
N W Ghonaim ◽  
L Xi ◽  
H Y Nie ◽  
J Francis ◽  
...  
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Time Of Flight ◽  
Static Condition ◽  
Soft Materials ◽  
Self Assembled Monolayer ◽  
Atomic Ions ◽  
Tof Sims ◽  
Self Assembled ◽  
Octadecylphosphonic Acid ◽  
Fluence Range

By using a self-assembled monolayer of octadecylphosphonic acid molecules, CH3(CH2)17PO(OH)2, on mica as a model of the “soft” materials, such as self-assembled monolayers (SAMs) and multilayers in many biological systems as well as artificially engineered molecular electronic systems, we have examined the effects of primary ion fluence on time-of-flight secondary ion mass spectrometry (TOF-SIMS) of the technologically important model. Our measurements clearly show that although the intensity per unit primary ion fluence of most atomic ions and many small fragment ions do not vary by more than 10% for the fluence range of 1010–1013 cm–2, the intensity of the parent molecular ion can drop by two orders of magnitude in this fluence range. While the changes are different for the primary ion beams of Bi3+ (25 keV, 45°), Bi+ (25 keV, 45°), and Ar+ (8 keV, 45°), they are all substantial, with the damage cross section induced by the Bi3+ beam being the largest (6 000 Å2). Since different secondary ions have quite different intensity changes, the analytical results derived from TOF-SIMS can vary significantly by the time and duration of the measurements in the TOF-SIMS experiment. Therefore, our results suggest that for TOF-SIMS of molecular layers such as SAMs, the primary ion fluence condition should be recorded and reported. In general, the validity of the static condition becomes questionable when the cumulative primary ion fluence exceeds 1 × 1011 cm–2.Key words: SIMS, static SIMS, TOF-SIMS, soft materials, self-assembled monolayer, bilayer, surface of biological materials.

Molecular surface analysis by TOF-SIMS

1992 ◽  
Vol 50 (2) ◽  
pp. 1556-1557
Author(s):  
Robert W. Odom
Keyword(s):  
Mass Spectrometry ◽  
Surface Analysis ◽  
Secondary Ion Mass Spectrometry ◽  
Molecular Ions ◽  
Molecular Surface ◽  
Tof Sims ◽  
Ion Mass Spectrometry ◽  
Static Conditions ◽  
Primary Ions ◽  
Secondary Ion

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) performs surface sensitive analysis of the elemental and molecular composition of solids. TOFSIMS is a relatively new embodiment of static secondary ion mass spectrometry (SSIMS) in which the dose of primary ions incident on the surface is typically less than 1012 ions/cm2. Since typical solid surfaces have an atomic density of 1015 atoms/cm2, this primary ion dose nominally removes less than 0.1% of a monolayer. Hence, SIMS analyses performed under these static conditions represent near surface analysis in which secondary ions are produced from the top few monolayers of the surface. The actual sampling depth is determined by the primary ion momentum, angle of incidence and chemistry of the surface. Since low dose primary ions cause minimal perturbation of the chemistry of the solid surface, SSIMS analyses often produce molecular or pseudo-molecular ions characteristic of the chemical composition of the surface. Thus, molecular ions or structurally significant fragment ions are often observed in SSIMS analyses of surfaces containing inorganic and organic residues, polymers surfaces, coatings, and biological materials such as tissues and membranes.

Carbon Black Surface Characterization by TOF-SIMS and XPS

1999 ◽  
Vol 72 (2) ◽  
pp. 384-397 ◽  
Author(s):  
P. Bertrand ◽  
L. T. Weng
Keyword(s):  
Carbon Black ◽  
Functional Groups ◽  
Surface Characterization ◽  
Secondary Ion Mass Spectrometry ◽  
Structural Information ◽  
Chemical Shifts ◽  
Molecular Ions ◽  
Chemical Information ◽  
Trace Detection ◽  
Tof Sims

Abstract The functional groups present at the carbon black (CB) surface contribute, along with the surface microstructure, to the CB surface activity which is known to be an important parameter for the rubber reinforcing properties. A direct detection of the foreign elements (H, N, O, S, Cl, …) present at the CB surface can be achieved with surface analytical techniques such as Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) and X-ray Photoelectron Spectoscopy (XPS). The combination of these two techniques is found to be very fruitful. Indeed, although the TOF-SIMS sensitivity is much higher than for XPS, allowing trace detection, this technique suffers from a lack of quantification which can be fulfilled by XPS. The chemical information on the functional groups obtained by both methods is complementary. In XPS, this information is deduced from the electron core level chemical shifts which are mainly influenced by the first neighboring atoms; whereas, in TOF-SIMS, the full molecular environment can be detected. Not only information on the surface groups, but also some structural information can be obtained. Indeed, the TOF-SIMS spectra of carbon black exhibit molecular ions which are characteristic of the surface aromaticity (graphene structure) and also specific clusters at high masses which seem to be related to the basic building block of carbon black particles.

scholarly journals Tribological Properties of Wax on Different Trees Leaf Surface Containing Different Chemical Components

2020 ◽  
Author(s):  
Yanqiu Xia ◽  
Xin Feng ◽  
Wenyi Zhang
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Leaf Surface ◽  
Friction Reduction ◽  
Chemical Components ◽  
Chemical Compositions ◽  
Chemical Action ◽  
Base Oil ◽  
Tof Sims ◽  
Surface Waxes ◽  
Secondary Ion

Abstract Three kinds of leaf-surface waxes were extracted from different trees, and their chemical compositions were analyzed by Gas Chromatography-Mass Spectrometer (GC-MS). A MFT-R4000 tester was employed to investigate the tribological performances of samples, and the Scanning Electron Microscope (SEM) and Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS) were used to characterize the morphologies and chemical compositions on the worn surfaces, respectively. The result showed that waxes can effectively improve the friction reduction and anti-wear abilities of base oil, and different composition of waxes have different improve degree. This can be attributed to the chemical compositions and degree of chemical action.

Applications of Time-OF-Flight Secondary Ion Mass Spectrometry (TOF-SIMS)

1990 ◽  
Vol 48 (2) ◽  
pp. 308-309
Author(s):  
Bruno Schueler ◽  
Robert W. Odom
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Structural Information ◽  
Time Of Flight ◽  
Biological Tissues ◽  
Polymer Surfaces ◽  
Tof Sims ◽  
Secondary Ions ◽  
Ion Mass Spectrometry ◽  
Secondary Ion

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) provides unique capabilities for elemental and molecular compositional analysis of a wide variety of surfaces. This relatively new technique is finding increasing applications in analyses concerned with determining the chemical composition of various polymer surfaces, identifying the composition of organic and inorganic residues on surfaces and the localization of molecular or structurally significant secondary ions signals from biological tissues. TOF-SIMS analyses are typically performed under low primary ion dose (static SIMS) conditions and hence the secondary ions formed often contain significant structural information.This paper will present an overview of current TOF-SIMS instrumentation with particular emphasis on the stigmatic imaging ion microscope developed in the authors’ laboratory. This discussion will be followed by a presentation of several useful applications of the technique for the characterization of polymer surfaces and biological tissues specimens. Particular attention in these applications will focus on how the analytical problem impacts the performance requirements of the mass spectrometer and vice-versa.

Optics-Free Visualization of Proteins in Single Cells by Time of Flight-Secondary Ion Mass Spectrometry Coupled with Genetically Encoded Chemical Tags

2020 ◽  
Author(s):  
Feifei Jia ◽  
Jie Wang ◽  
Yanyan Zhang ◽  
Qun Luo ◽  
Luyu Qi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Single Cells ◽  
Time Of Flight ◽  
E Coli ◽  
Tof Sims ◽  
Ion Mass Spectrometry ◽  
Chemical Tags ◽  
Secondary Ion

<p></p><p><i>In situ</i> visualization of proteins of interest at single cell level is attractive in cell biology, molecular biology and biomedicine, which usually involves photon, electron or X-ray based imaging methods. Herein, we report an optics-free strategy that images a specific protein in single cells by time of flight-secondary ion mass spectrometry (ToF-SIMS) following genetic incorporation of fluorine-containing unnatural amino acids as a chemical tag into the protein via genetic code expansion technique. The method was developed and validated by imaging GFP in E. coli and human HeLa cancer cells, and then utilized to visualize the distribution of chemotaxis protein CheA in E. coli cells and the interaction between high mobility group box 1 protein and cisplatin damaged DNA in HeLa cells. The present work highlights the power of ToF-SIMS imaging combined with genetically encoded chemical tags for <i>in situ </i>visualization of proteins of interest as well as the interactions between proteins and drugs or drug damaged DNA in single cells.</p><p></p>

scholarly journals Chemical Evaluation of Eumelanin Maturation by ToF-SIMS and Alkaline Peroxide Oxidation HPLC Analysis

2020 ◽  
Vol 22 (1) ◽  
pp. 161
Author(s):  
Martin Jarenmark ◽  
Peter Sjövall ◽  
Shosuke Ito ◽  
Kazumasa Wakamatsu ◽  
Johan Lindgren
Keyword(s):  
Molecular Structure ◽  
Secondary Ion Mass Spectrometry ◽  
Chemical Characterization ◽  
Experimental Treatment ◽  
Negative Ion ◽  
Pressure Treatment ◽  
Peroxide Oxidation ◽  
Specific Chemical ◽  
Tof Sims

Residual melanins have been detected in multimillion-year-old animal body fossils; however, confident identification and characterization of these natural pigments remain challenging due to loss of chemical signatures during diagenesis. Here, we simulate this post-burial process through artificial maturation experiments using three synthetic and one natural eumelanin exposed to mild (100 °C/100 bar) and harsh (250 °C/200 bar) environmental conditions, followed by chemical analysis employing alkaline hydrogen peroxide oxidation (AHPO) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Our results show that AHPO is sensitive to changes in the melanin molecular structure already during mild heat and pressure treatment (resulting, e.g., in increased C-C cross-linking), whereas harsh maturation leads to extensive loss of eumelanin-specific chemical markers. In contrast, negative-ion ToF-SIMS spectra are considerably less affected by mild maturation conditions, and eumelanin-specific features remain even after harsh treatment. Detailed analysis of ToF-SIMS spectra acquired prior to experimental treatment revealed significant differences between the investigated eumelanins. However, systematic spectral changes upon maturation reduced these dissimilarities, indicating that intense heat and pressure treatment leads to the formation of a common, partially degraded, eumelanin molecular structure. Our findings elucidate the complementary nature of AHPO and ToF-SIMS during chemical characterization of eumelanin traces in fossilized organismal remains.

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