SIMS2015 Session IS-ThP: In-Situ Liquid SIMS Poster Session
Time Period ThP Sessions | Topic IS Sessions | Time Periods | Topics | SIMS2015 Schedule
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IS-ThP-1 Characterization of Electrochemical Reaction Intermediates Using Liquid ToF-SIMS
Zhaoying Wang (CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences; W. R. Wiley Environmental Molecular Science Laboratory, Pacific Northwest National Laboratory); Fuyi Wang (Beijing National Laboratory for Molecular Sciences; CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences; Beijing Centre for Mass Spectrometry, China); Zihua Zhu (W. R. Wiley Environmental Molecular Science Laboratory, Pacific Northwest National Laboratory) Identification of the electrochemical reaction intermediates is very important for understanding the reaction mechanism. However, it has been a great challenge due to their short lifetime and intrinsic instability for a long time. Traditional electrochemical analytical method such as cyclic voltammetry (CV)[1], polarography[2], chronoamperometry[3] and bulk electrolysis[4] as well as time-resolved spectroscopy[5] in case of photo-induced electron transfer, have been used to study mechanisms of electrochemical redox reactions. However, only indirect or ambiguous identifications can be achieved, which may not be sufficient for interpreting the detailed reaction process at the electrode/electrolyte interface. Other spectroscopic techniques (e.g., IR, NMR, XPS, XAS, ESI-MS) have also been used to detect redox reaction intermediates[6], but only limited information can be obtained due to complexity of the electrode/electrolyte interface. In the present work, a novel in situ method based on time-of-flight secondary ion mass spectrometry (ToF-SIMS) in combination with a microfluidic cell was developed to monitor the real-time electro-oxidation reaction on a gold electrode. By using the classical ascorbic acid (AA) oxidation as a model, we successfully detected the key electro-chemically oxidized intermediates of AA close to the working electrode surface, which strongly supports the proposed oxidation mechanism of AA reported previously[7]. Such novel liquid cell ToF-SIMS method provides direct insight into redox processes at the electrode/electrolyte interface and may be applicable for other reaction intermediates identifications at solid-liquid interfaces. |
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IS-ThP-2 Laser Irradiation Effect on Lubricant Films for HAMR Application
Rong Ji (Data Storage Institute, Singapore) Heat assisted magnetic recording (HAMR) is one of the promising approaches to achieve higher and higher recording density and to overcome the superparamagnetic limit. Technically, HAMR uses a beam of laser to momentarily heat the recording area of the medium. As results, the coercivity of high magnetic anisotropy recording medium has been momentarily reduced and the magnetization in the extremely small grains range has been realized with high thermal stability. This technology requires all media components including media lubricant are with high thermal stability. To meet this requirement, a novel type of lubricant – IDL1 was designed, synthesized and tested by our team to be promising potential lubricant for HAMR application. For further research, this paper studies HAMR laser irradiation effect on our novel lubricant, IDL1 through comparing the results with commercial lubricant, Z-Tetraol. As shown in Figures 1 and 2, after laser irradiation, IDL1 shows less lubricant loss and less lubricant decomposition than commercial lubricant, Z-Tetraol. Detailed XPS and TOF-SIMS analysis will reveal the related mechanism. This study is expected to provide valuable information for future HAMR lubricant research. |
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IS-ThP-3 Correlative Imaging of Single Mammalian Cells in the Hydrated Microenvironment by ToF-SIMS and Structure Illumination Microscopy
Xin Hua, Craig Szymanski, Yufan Zhou, Zhaoying Wang, James Evans, Zihua Zhu, Galya Orr (Pacific Northwest National Laboratory); Songqin Liu (Southeast University, China); Xiao-Ying Yu (Pacific Northwest National Laboratory) Single cell analysis is very important in understanding and predicting cell behaviors as a result of cellular heterogeneities. In this work, correlative imaging by time-of-flight secondary ion mass spectrometry (ToF-SIMS) and super resolution fluorescence structured illumination microscope (SIM), coupled with a microreactor SALVI (system for analysis at the liquid vacuum interface) is used to address the scientific challenge of spatially mapping chemical components and following the dynamics of single cells in their liquid microenvironment. Mouse lung C10 cell growth was monitored and confirmed by SIM imaging and cell changes were analyzed by direct probing of hydrated cell using ToF-SIMS. Correlative imaging of different parts of a single cell was presented. Comparisons of ToF-SIMS m/z spectra among hydrated cells, hydrated cells treated with ZnO nanoparticles, and various control samples show characteristic phospholipids fragments of mammalian cells and zinc ions . Depth profiling was used to provide time- and space-resolved imaging of the cells inside the microchannel. 2D and 3D images of representative fragments of single C10 cells were presented and discussed for the first time. Principal component analysis of images was also conducted to evaluate the intrinsic similarities and discriminations among samples. Our results demonstrate the feasibility for in situ probing of mammalian cells in the hydrated microenvironment using ToF-SIMS. Correlative imaging using SIM and ToF-SIMS provides information across different space scales for investigating cell- exogenous substance interactions. SALVI demonstrates a great potential for studying intracellular processes in the future. |