Profiling with Depth Resolution of Sub-nm for SiO2/ SiC Interface by Dual-Beam TOF-SIMS Combined with Simulation

For precise investigation of distribution for impurity or composition at SiO2/SiC interface, dual-beam Time-of-flight Secondary ion mass spectrometry (TOF-SIMS) with low energy sputtering beam was available. In addition to the experimental profiles, simulation using MRI model, in which Mixing, Roughness and Information depth were employed as parameters, enabled to acquire a more authentic distribution at the SiO2/SiC interface. Slight discrepancy on depth profiles between samples with different surface roughness was duplicated on the convoluted profiles in the simulation. Moreover, reconstructed profile of nitrogen indicated a real distribution with less impact of mixing and roughness, although that may contain uncertainty due to incompletion in the simulation model or variation of the distribution owing to detection species in the experiment. From the result of carbon profiles of both experimental and convoluted profiles, the relative discrepancy on the carbon distribution between samples was clarified, which suggested the possibility that a carbon thin layer at the SiO2/SiC interface would be found in the future.

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100135149 ◽

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.

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

10.26434/chemrxiv.12046125 ◽

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

In situ 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 in situ visualization of proteins of interest as well as the interactions between proteins and drugs or drug damaged DNA in single cells.

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