Name: quantifying x-ray fluorescence data using maps
Uploaded: 2018-02-17T12:30:00.000+00:00
Duration: 14 min 58 s
Description: Watch this Scientific Journal Video about Quantifying X-Ray Fluorescence Data Using MAPS at JoVE.com

我们承认美国能源部根据合同 DE-EE0005948 提供的资金。该中心的纳米材料和先进的光子源, 两个办公室的科学用户设施, 得到了美国能源部, 科学办公室, 能源科学办公室, 根据合同号。DE-AC02-06CH11357。这一材料是根据国家科学基金会 (nsf) 和能源部 (能源部) 在 NSF CA 号下所支助的工作为基础的。EEC-1041895。视频编辑是由亚利桑那州立大学的 VISLAB 完成的。本材料所表达的任何意见、发现和结论或建议都是作者的观点, 并不一定反映在 NSF 或能源部。T.N. 得到了由国家科学基金会资助的 IGERT-太阳奖学金 (1144616 奖) 的支持。

<ol>
	<li>Geraki, K., Farquharson, M. J., Bradley, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=X-ray+fluorescence+and+energy+dispersive+x-ray+diffraction+for+the+quantification+of+elemental+concentrations+in+breast+tissue.">X-ray fluorescence and energy dispersive x-ray diffraction for the quantification of elemental concentrations in breast tissue.</a> Phys. Med. Biol. 49, 99-110 (2004).</li><li>Paunesku, T., Vogt, S., Maser, J., Lai, B., Woloschak, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=X-ray+fluorescence+microprobe+imaging+in+biology+and+medicine.">X-ray fluorescence microprobe imaging in biology and medicine.</a> J. Cell. Biochem. 99 (6), 1489-1502 (2006).</li><li>Twining, B. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantifying+Trace+Elements+in+Individual+Aquatic+Protist+Cells+with+a+Synchrotron+X-ray+Fluorescence+Microprobe.">Quantifying Trace Elements in Individual Aquatic Protist Cells with a Synchrotron X-ray Fluorescence Microprobe.</a> Anal. Chem. 75 (15), 3806-3816 (2003).</li><li>de Jonge, M. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+3D+elemental+microtomography+of+Cylotella+meneghiniana+at+400-nm+resolution.">Quantitative 3D elemental microtomography of Cylotella meneghiniana at 400-nm resolution.</a> Proc. Natl. Acad. Sci. 107 (36), 15676-15680 (2010).</li><li>Du&#265;i&#263;, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhancement+in+statistical+and+image+analysis+for+in+situ+&#181;SXRF+studies+of+elemental+distribution+and+co-localization,+using+Dioscorea+balcanica.">Enhancement in statistical and image analysis for in situ &#181;SXRF studies of elemental distribution and co-localization, using Dioscorea balcanica.</a> J. Synchrotron Rad. 20, 339-346 (2013).</li><li>Kemner, K. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Elemental+and+Redox+Analysis+of+Single+Bacterial+Cells+by+X-ray+Microbeam+Analysis.">Elemental and Redox Analysis of Single Bacterial Cells by X-ray Microbeam Analysis.</a> Science. 306 (5696), 686-687 (2004).</li><li>Bertoni, M. I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanoprobe+X-ray+fluorescence+characterization+of+defects+in+large-area+solar+cells.">Nanoprobe X-ray fluorescence characterization of defects in large-area solar cells.</a> Energy Environ. Sci. 4 (10), 4252-4257 (2011).</li><li>Fenning, D. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Iron+distribution+in+silicon+after+solar+cell+processing:+Synchrotron+analysis+and+predictive+modeling.">Iron distribution in silicon after solar cell processing: Synchrotron analysis and predictive modeling.</a> Appl. Phys. Lett. 98 (162103), (2011).</li><li>Buonassisi, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantifying+the+effect+of+metal-rich+precipitates+on+minority+carrier+diffusion+length+in+multicrystalline+silicon+using+synchrotron-based+spectrally+resolved+x-ray+beam+induced+current.">Quantifying the effect of metal-rich precipitates on minority carrier diffusion length in multicrystalline silicon using synchrotron-based spectrally resolved x-ray beam induced current.</a> Appl. Phys. Lett. 87 (044101), (2005).</li><li>Stuckelberger, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Engineering+solar+cells+based+on+correlative+X-ray+microscopy.">Engineering solar cells based on correlative X-ray microscopy.</a> J. Mat. Res. 32 (10), 1825-1854 (2017).</li><li>Streeck, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Grazing-incidence+x-ray+fluorescence+analysis+for+non-destructive+determination+of+In+and+Ga+depth+profiles+in+Cu(In,Ga)Se2+absorber+films.">Grazing-incidence x-ray fluorescence analysis for non-destructive determination of In and Ga depth profiles in Cu(In,Ga)Se2 absorber films.</a> Appl. Phys. Lett. 103 (113904), (2013).</li><li>Luo, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spatially+Heterogeneous+Chlorine+Incorporation+in+Organic-Inorganic+Perovskite+Solar+Cells.">Spatially Heterogeneous Chlorine Incorporation in Organic-Inorganic Perovskite Solar Cells.</a> Chem. Mater. 28, 6536-6543 (2016).</li><li>Stuckelberger, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Charge+Collection+in+Hybrid+Perovskite+Solar+Cells:+Relation+to+the+Nanoscale+Elemental+Distribution.">Charge Collection in Hybrid Perovskite Solar Cells: Relation to the Nanoscale Elemental Distribution.</a> IEEE J. Photovolt. 7 (2), 590-597 (2017).</li><li>Vogt, S., Maser, J., Jacobsen, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Data+analysis+for+X-ray+fluorescence+imaging.">Data analysis for X-ray fluorescence imaging.</a> J. Phys. IV France. 104, 617-622 (2003).</li><li>West, B. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Grain+engineering:+How+nanoscale+inhomogeneities+can+control+charge+collection+in+solar+cells.">Grain engineering: How nanoscale inhomogeneities can control charge collection in solar cells.</a> Nano Energy. 32, 488-493 (2017).</li><li>Krause, M. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Atomic+Radiative+and+Radiationless+Yields+for+K+and+L+Shells.">Atomic Radiative and Radiationless Yields for K and L Shells.</a> J. Phys. Chem. Ref. Data. 8 (2), 307-327 (1979).</li><li>Hubbell, J. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Review,+Bibliography,+and+Tabulation+of+K,L,+and+Higher+Atomic+Shell+X-Ray+Fluorescence+Yields.">A Review, Bibliography, and Tabulation of K,L, and Higher Atomic Shell X-Ray Fluorescence Yields.</a> J. Phys. Chem. Ref. Data. 23 (2), 339-364 (1994).</li><li>Ravel, B., Newville, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ATHENA,+ARTEMIS,+HEPHAESTUS:+data+analysis+for+X-ray+absorption+spectroscopy+using+IFEFFIT.">ATHENA, ARTEMIS, HEPHAESTUS: data analysis for X-ray absorption spectroscopy using IFEFFIT.</a> J. Synchrotron Rad. 12, 537-541 (2005).</li><li>West, B. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=X-ray+fluorescence+at+nanoscale+resolution+for+multicomponent+layered+structures:+a+solar+cell+case+study.">X-ray fluorescence at nanoscale resolution for multicomponent layered structures: a solar cell case study.</a> J Synchrotron Rad. 24, (2017).</li><li>De Boer, D. K. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Calculation+of+X-Ray+Fluorescence+Intensities+from+Bulk+and+Multilayer+Samples.">Calculation of X-Ray Fluorescence Intensities from Bulk and Multilayer Samples.</a> X-Ray Spectrom. 19 (3), 145-154 (1990).</li><li>Lachance, G. R., Claisse, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Quantitative X-ray Fluorescence Analysis: Theory and Application. , (1995).</li><li>Sokaras, D., Karydas, A. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Secondary+Fluorescence+Enhancement+in+Confocal+X-ray+Microscopy+Analysis.">Secondary Fluorescence Enhancement in Confocal X-ray Microscopy Analysis.</a> Anal. Chem. 81 (12), 4946-4954 (2009).</li></ol>

作者没有什么可透露的。

这些数字显示了使用此过程对数据进行拟合的重要性。图 1 (右) 和 2 (底端)显示了一个由适当的管接头产生的代表性结果。如果有一个不够合适的, 积分频谱图像将显着关闭, 结果量化数据将有错误, 虽然这些将很难发现在大多数情况下。对于某些样本类型, 该标准不代表样本中的元素, 特别是由于样本不包含标准中的任何元素, 因此量化仅依赖于对所有元素的推断信息。兴趣.在这样的?...

基于同步辐射的 XRF 已经在多个学科中使用了数十年。例如, 它已被用于生物学上的研究, 如 Geraki et 等, 他们在其中量化微量的金属浓度在癌和非癌性乳腺组织1。更笼统地说, 定量 XRF 已被应用于广泛的生物学研究, 涉及细胞和组织中的金属浓度, 如 Paunesku et . 所述。2. 同样, 研究了海洋原生生物的微量元素3, 4, 甚至微和营养素分布在植物细胞5 内观察到。通过 Kemner et 等进行工作。通过定量 XRF 分析, 6确定了单个细菌细胞在形态学和元素组成上的显著差异。此外, 与本文所揭示的例子特别相关的是, 研究太阳能电池器件的材料科学家利用高分辨率 XRF 研究硅半导体中亚微米金属杂质的存在7,8, 有关元素分布如何影响太阳能设备中的电气性能的相关工作9,10, 通过放牧入射 X 射线识别 CIGS 薄膜太阳能电池的深度依赖性梯度荧光 (GIXRF) 11。
许多研究不仅利用同步辐射 x 射线荧光的高分辨率能力来研究空间分布, 而且还可以定量地绘制数值结论的信息。在许多研究中, 了解与上述空间分布有关的元素浓度是至关重要的。例如, 在 Geraki et al的工作中, 该研究需要量化癌症和非癌性乳腺组织中铁、铜、锌和钾浓度的差异, 以便更好地了解哪些浓度会有害于人体组织1。同样地, 工作由罗et al。利用量化的 XRF 来识别在钙钛矿太阳能电池中合成的少量氯, 并与含有含氯的前体结合使用12。因此, 对于某些需要元素浓度的研究, 适当的量化是必要的和关键的一步。
从 X 射线荧光 (XRF) 测量中定量元素浓度的过程将荧光强度计数转化为质量浓度 (例如µg/cm2)。原始光谱显示能量色散荧光探测器收集的光子的数量作为能量的函数。光谱首先适合, 然后比较标准测量计算量化数据。特别是, 拟合荧光光谱的第一步即使对元素的定性分析也是至关重要的。这是因为在拟合之前, 计数是基于它们的能量作废的, 当样品中包含有类似荧光跃迁的两个元素时, 就成了一个问题。在这种情况下, 计数可能不正确作废, 因而与错误元素关联。
为了准确得出样品中元素相对数量的结论, 通常也需要对 XRF 光谱进行量化。如果没有适当的量化, 将直接比较重元素和轻元素的计数, 忽略捕获剖面的差异、吸收和荧光概率、荧光光子的衰减以及元素的吸收边缘, 从入射能量, 这一切都影响到光子的数量, 击中探测器。因此, 对每张地图的光谱进行拟合, 并将峰值强度与标准进行比较, 这两种方法都是在下面的过程中进行的, 对于准确量化每个元素浓度是至关重要的。
我们演示如何将荧光光子的原始计数转换为每平方厘米 (µg/cm2) 的单位, 首先拟合一个积分谱, 或者在每个测量点或像素上产生的所有单个光谱的汇总频谱。在2D 地图上。这一光谱显示了样本中不同元素的相对强度。某一元素的吸收边缘与入射光束能量的距离影响其荧光峰的强度。一般而言, 两种能量越近, 这些元素产生的强度就越大, 尽管情况并非总是如此。Ref 13中的图4显示了 methylammonium 铅钙钛矿太阳能电池中的多数元素与所产生的强度直接相关的 X 射线光子吸收长度的依赖性。这说明了元素对能量的荧光响应, 表明它不是随着入射能量距离的增加而持续减少, 而是依赖于元素本身。
这种关系的结果是, 元素通道的原始元素浓度可能会出现较高的激发能量接近入射能量, 即使这些元素的真正数量是较低的与其他元素的激发能量更远的事件。因此, 强度的能量依赖性, 以及其他因素, 如荧光率变化, 不同的吸收边缘, 探测器灵敏度, 测量背景等, 是为什么拟合数据是非常重要的, 在绘制之前关于观察到的元素数量的结论。然后, 我们将一个拟合算法应用于积分频谱, 用户可以通过文本文档定义元素和参数。
由 Vogt et创建的算法。14, 利用感兴趣的区域 (ROI) 筛选, 在其中集成了某些元素的峰值区域和主成分分析 (PCA)。首先, PCA 是为了识别非常明显的元素和峰值。这使得噪声与真实信号分离。其次, 确定的原理元件的数值量化, 这是重要的 deconvoluting 不同的元素峰值与相同的励磁能量, 例如重叠的 Au Mα和 P Kα。最后, 通过集成指定区域, ROI 筛选可以应用于数字数据。
为了将计数与元素浓度联系起来, 一个量化良好的参考 (通常称为 "标准") 是在相同的测量条件、几何和能量下测量的, 如所研究的样本。这个标准经常是从德累斯顿 AXO 或从国家标准和技术协会 (NIST)。它们覆盖了各种不同的元素, 并带有列表元素分布。在相同的测量条件下, 对标准计数的感兴趣样本计数的规范化, 为感兴趣样本的元素量化提供了依据。
更具体地说, 地图通过程序已知的标准信息 (如 AXO 和 NIST 标准的情况) 或通过输入到单独文件中的数据来确定标准的元素及其浓度 (在使用的标准不同)。根据这些信息, 该程序将测量设置下标准元素的测量强度与嵌入在地图中的预期浓度联系起来。然后, 它创建一个缩放因子来调整任何偏移量, 并将此缩放因子推断到标准中未包括的所有剩余元素。然后, 缩放系数包括测量设置的偏移量, 以及在映射中提供的与µg/cm2中的原始计数到区域密度的线性转换的信息。
在这里, 我们演示如何利用该程序, 地图, 由美国 Vogt 博士开发, 以量化数据获得从荧光能力的同步辐射在阿贡国家实验室 (这个) 14。用于演示的数据是使用10图1中所示的测量设置在这个2区 ID D 上获取的。该拟合过程也可应用于从其他同步辐射中采集的数据, 但请注意, 这个同步辐射的某些特性嵌入到程序中, 需要更新。

quantifying x-ray fluorescence data using maps

通过将原始光谱与已知标准进行拟合, 对 X 射线荧光 (XRF) 显微图进行量化是评价材料中化学成分和元素分布的关键。基于同步辐射的 XRF 已成为各种研究课题的整体表征技术, 特别是由于其无损性质和高灵敏度。今天, 同步辐射可以在微米以下的空间分辨率下获得荧光数据, 从而对纳米尺度的成分变化进行评估。通过适当的量化, 可以获得深入、高分辨率的元素隔离、化学计量关系和聚类行为的理解。
本文解释了如何使用阿贡国家实验室开发的地图拟合软件, 以量化全2维 XRF 图。我们作为一个例子, 从铜 (in, Ga) Se2太阳能电池, 采取在先进的光子源光束线 2-ID D 在阿贡国家实验室。我们展示了拟合原始数据的标准程序, 演示了如何评估合适的质量并呈现程序生成的典型输出。此外, 我们在这篇手稿中讨论了某些软件限制, 并提出了如何进一步纠正数据准确和代表性的空间解析, 元素浓度的建议。

下面的数字可以看到适当的拟合结果示例。首先, 在图 1中, 直接比较在一个较差的匹配和一个适合于积分谱之间。坏的适合是修复的两个确保没有元素丢失, 例如, 铜, 其中有一个明确的峰值在图 1(左), 但不包括在配合, 并调整 L 和 K 线的分支比率, 以提高准确性。图 2改为显示在管接头前后元素通道之间的?...

Watch this Scientific Journal Video about Quantifying X-Ray Fluorescence Data Using MAPS at JoVE.com

Quantifying X-Ray Fluorescence Data Using MAPS

在这里, 我们演示使用 X 射线荧光拟合软件, 地图, 由阿贡国家实验室创建的荧光显微数据的量化。结果的量化数据有助于了解样本中的元素分布和化学计量比率。

利用地图量化 X 射线荧光数据

The quantification of X-ray fluorescence (XRF) microscopy maps by fitting the raw spectra to a known standard is crucial for evaluating chemical ...

quantifying-x-ray-fluorescence-data-using-maps

Research

JoVE Journal

Chemistry

10.7K 次观看.  Arizona State University. 在这里, 我们演示使用 X 射线荧光拟合软件, 地图, 由阿贡国家实验室创建的荧光显微数据的量化。结果的量化数据有助于了解样本中的元素分布和化学计量比率。

视频: Quantifying X-Ray Fluorescence Data Using MAPS

Preparing Adherent Cells for X-ray Fluorescence Imaging by Chemical Fixation

X-ray fluorescence imaging allows us to non-destructively measure the spatial distribution and concentration of multiple elements simultaneously over large or small sample areas. It has been applied in many areas of science, including materials science, geoscience, studying works of cultural heritage, and in chemical biology. In the case of chemical biology, for example, visualizing the metal distributions within cells allows us to study both naturally-occurring metal ions in the cells, as well as exogenously-introduced metals such as drugs and nanoparticles. Due to the fully hydrated nature of nearly all biological samples, cryo-fixation followed by imaging under cryogenic temperature represents the ideal imaging modality currently available. However, under the circumstances that such a combination is not easily accessible or practical, aldehyde based chemical fixation remains useful and sometimes inevitable. This article describes in as much detail as possible in the preparation of adherent mammalian cells by chemical fixation for X-ray fluorescent imaging.

Here, we present a protocol on how to determine the quantity and distribution of metals in a sample using synchrotron X-ray fluorescence. We focus on adherent cells, and describe the chemical fixation method to prepare this sample. We then describe how to mount and image the sample using synchrotron X-rays.

化学固定准备贴壁细胞的X射线荧光成像

X-ray fluorescence imaging allows us to non-destructively measure the spatial distribution and concentration of multiple elements simultaneously over ...

科研

化学

Energy Dispersive X-ray Tomography for 3D Elemental Mapping of Individual Nanoparticles

Energy dispersive X-ray spectroscopy within the scanning transmission electron microscope (STEM) provides accurate elemental analysis with high spatial resolution, and is even capable of providing atomically resolved elemental maps. In this technique, a highly focused electron beam is incident upon a thin sample and the energy of emitted X-rays is measured in order to determine the atomic species of material within the beam path. This elementally sensitive spectroscopy technique can be extended to three dimensional tomographic imaging by acquiring multiple spectrum images with the sample tilted along an axis perpendicular to the electron beam direction.
Elemental distributions within single nanoparticles are often important for determining their optical, catalytic and magnetic properties. Techniques such as X-ray tomography and slice and view energy dispersive X-ray mapping in the scanning electron microscope provide elementally sensitive three dimensional imaging but are typically limited to spatial resolutions of &gt; 20 nm. Atom probe tomography provides near atomic resolution but preparing nanoparticle samples for atom probe analysis is often challenging. Thus, elementally sensitive techniques applied within the scanning transmission electron microscope are uniquely placed to study elemental distributions within nanoparticles of dimensions 10-100 nm.
Here, energy dispersive X-ray (EDX) spectroscopy within the STEM is applied to investigate the distribution of elements in single AgAu nanoparticles. The surface segregation of both Ag and Au, at different nanoparticle compositions, has been observed.

The use of energy dispersive X-ray tomography in the scanning transmission electron microscope to characterize elemental distributions within single nanoparticles in three dimensions is described.

能量色散X射线断层摄影术对个人纳米3D元素映射

Energy dispersive X-ray spectroscopy within the scanning transmission electron microscope (STEM) provides accurate elemental analysis with high spatial ...

工程学

In Situ Detection and Single Cell Quantification of Metal Oxide Nanoparticles Using Nuclear Microprobe Analysis

Micro-analytical techniques based on chemical element imaging enable the localization and quantification of chemical composition at the cellular level. They offer new possibilities for the characterization of living systems and are particularly appropriate for detecting, localizing and quantifying the presence of metal oxide nanoparticles both in biological specimens and the environment. Indeed, these techniques all meet relevant requirements in terms of (i) sensitivity (from 1 up to 10 &#181;g.g-1 of dry mass), (ii) micrometer range spatial resolution, and (iii) multi-element detection. Given these characteristics, microbeam chemical element imaging can powerfully complement routine imaging techniques such as optical and fluorescence microscopy. This protocol describes how to perform a nuclear microprobe analysis on cultured cells (U2OS) exposed to titanium dioxide nanoparticles. Cells must grow on and be exposed directly in a specially designed sample holder used on the optical microscope and in the nuclear microprobe analysis stages. Plunge-freeze cryogenic fixation of the samples preserves both the cellular organization and the chemical element distribution. Simultaneous nuclear microprobe analysis (scanning transmission ion microscopy, Rutherford backscattering spectrometry and particle induced X-ray emission) performed on the sample provides information about the cellular density, the local distribution of the chemical elements, as well as the cellular content of nanoparticles. There is a growing need for such analytical tools within biology, especially in the emerging context of Nanotoxicology and Nanomedicine for which our comprehension of the interactions between nanoparticles and biological samples must be deepened. In particular, as nuclear microprobe analysis does not require nanoparticles to be labelled, nanoparticle abundances are quantifiable down to the individual cell level in a cell population, independently of their surface state.

In Situ Detection and Single Cell Quantification of Metal Oxide Nanoparticles Using Nuclear Microprobe Analysis

We describe a procedure for the detection of chemical elements present in situ in human cells as well as their in vitro quantification. The method is well-suited to any cell type and is particularly useful for quantitative chemical analyses in single cells following in vitro metal oxide nanoparticles exposure.

原位金属氧化物纳米粒子的核探针检测与单细胞定量研究

Micro-analytical techniques based on chemical element imaging enable the localization and quantification of chemical composition at the cellular level. ...

Obtaining 3D Chemical Maps by Energy Filtered Transmission Electron Microscopy Tomography

Energy filtered transmission electron microscopy tomography (EFTEM tomography) can provide three-dimensional (3D) chemical maps of materials at a nanometric scale. EFTEM tomography can separate chemical elements that are very difficult to distinguish using other imaging techniques. The experimental protocol described here shows how to create 3D chemical maps to understand the chemical distribution and morphology of a material. Sample preparation steps for data segmentation are presented. This protocol permits the 3D distribution analysis of chemical elements in a nanometric sample. However, it should be noted that currently, the 3D chemical maps can only be generated for samples that are not beam sensitive, since the recording of filtered images requires long exposure times to an intense electron beam. The protocol was applied to quantify the chemical distribution of the components of two different heterogeneous catalyst supports. In the first study, the chemical distribution of aluminum and titanium in titania-alumina supports was analyzed. The samples were prepared using the swing-pH method. In the second, the chemical distribution of aluminum and silicon in silica-alumina supports that were prepared using the sol-powder and mechanical mixture methods was examined.

This paper describes a protocol to achieve 3D chemical maps combining energy filtered imaging and electron tomography. The chemical distribution of two catalyst supports formed by elements that are difficult to distinguish by other imaging techniques was studied. Each application consists of mapping overlapped chemical elements - respectively spaced-ionization edges.

通过能量过滤透射电镜成像获得3D 化学图

Energy filtered transmission electron microscopy tomography (EFTEM tomography) can provide three-dimensional (3D) chemical maps of materials at a ...

Elemental-sensitive Detection of the Chemistry in Batteries through Soft X-ray Absorption Spectroscopy and Resonant Inelastic X-ray Scattering

Energy storage has become more and more a limiting factor of today's sustainable energy applications, including electric vehicles and green electric grid based on volatile solar and wind sources. The pressing demand of developing high-performance electrochemical energy storage solutions, i.e., batteries, relies on both fundamental understanding and practical developments from both the academy and industry. The formidable challenge of developing successful battery technology stems from the different requirements for different energy-storage applications. Energy density, power, stability, safety, and cost parameters all have to be balanced in batteries to meet the requirements of different applications. Therefore, multiple battery technologies based on different materials and mechanisms need to be developed and optimized. Incisive tools that could directly probe the chemical reactions in various battery materials are becoming critical to advance the field beyond its conventional trial-and-error approach. Here, we present detailed protocols for soft X-ray absorption spectroscopy (sXAS), soft X-ray emission spectroscopy (sXES), and resonant inelastic X-ray scattering (RIXS) experiments, which are inherently elemental-sensitive probes of the transition-metal 3d and anion 2p states in battery compounds. We provide the details on the experimental techniques and demonstrations revealing the key chemical states in battery materials through these soft X-ray spectroscopy techniques.

Here, we present a protocol for typical experiments of soft X-ray absorption spectroscopy (sXAS) and resonant inelastic X-ray scattering (RIXS) with applications in battery material studies.

软 x 射线吸收光谱和共振非弹性 x 射线散射法检测电池化学成分的元素敏感度

Energy storage has become more and more a limiting factor of today's sustainable energy applications, including electric vehicles and green electric grid ...

Synchrotron X-ray Microdiffraction and Fluorescence Imaging of Mineral and Rock Samples

In this report, we describe a detailed procedure for acquiring and processing&#160;x-ray microfluorescence (&#956;XRF), and Laue and powder microdiffraction two-dimensional (2D) maps at beamline 12.3.2 of the Advanced Light Source (ALS), Lawrence Berkeley National Laboratory. Measurements can be performed on any sample that is less than 10 cm x 10 cm x 5 cm, with a flat exposed surface. The experimental geometry is calibrated using standard materials (elemental standards for XRF, and crystalline samples such as Si, quartz, or Al2O3 for diffraction). Samples are aligned to the focal point of the x-ray microbeam, and raster scans are performed, where each pixel of a map corresponds to one measurement, e.g., one XRF spectrum or one diffraction pattern. The data are then processed using the in-house developed software XMAS, which outputs text files, where each row corresponds to a pixel position. Representative data from moissanite and an olive snail shell are presented to demonstrate data quality, collection, and analysis strategies.

We describe a beamline setup meant to carry out rapid two-dimensional x-ray fluorescence and x-ray microdiffraction mapping of single crystal or powder samples using either Laue (polychromatic radiation) or powder (monochromatic radiation) diffraction. The resulting maps give information about strain, orientation, phase distribution, and plastic deformation.

矿物和岩石样品的同步辐射 x 射线 Microdiffraction 和荧光成像

In this report, we describe a detailed procedure for acquiring and processing&#160;x-ray microfluorescence (&#956;XRF), and Laue and powder ...

Expression of Cementitious Pore Solution and the Analysis of Its Chemical Composition and Resistivity Using X-ray Fluorescence

The goal of this method is to determine the chemical composition and electrical resistivity of cementitious pore solution expressed from a fresh paste sample. The pore solution is expressed from a fresh paste sample using a pressurized nitrogen gas system. The pore solution is then immediately transferred to a syringe to minimize evaporation and carbonation. After that, assembled testing containers are used for the X-ray fluorescence (XRF) measurement. These containers consist of two concentric plastic cylinders and a polypropylene film which seals one of the two open sides. The pore solution is added into the container immediately prior to the XRF measurement. The XRF is calibrated to detect the main ionic species in the pore solution, in particular, sodium (Na+), potassium (K+), calcium (Ca2+), and sulfide (S2-), to calculate sulfate (SO42-) using stoichiometry. The hydroxides (OH-) can be calculated from a charge balance. To calculate the electrical resistivity of the solution, the concentrations of the main ionic species and a model by Snyder et al. are used. The electrical resistivity of the pore solution can be used, along with the electrical resistivity of concrete, to determine the formation factor of concrete. XRF is a potential alternative to current methods to determine the composition of pore solution, which can provide benefits in terms of reduction in time and costs.

This protocol describes the procedure to express fresh pore solution from cementitious systems and the measurement of its ionic composition using X-ray fluorescence. The ionic composition can be used to calculate pore solution electrical resistivity, which can be used, together with concrete electrical resistivity, to determine the formation factor.

胶孔溶液的表达及其化学成分和电阻率的 X 射线荧光分析

The goal of this method is to determine the chemical composition and electrical resistivity of cementitious pore solution expressed from a fresh paste ...

Murine Model for Non-invasive Imaging to Detect and Monitor Ovarian Cancer Recurrence

Epithelial ovarian cancer is the most lethal gynecologic malignancy in the United States. Although patients initially respond to the current standard of care consisting of surgical debulking and combination chemotherapy consisting of platinum and taxane compounds, almost 90% of patients recur within a few years. In these patients the development of chemoresistant disease limits the efficacy of currently available chemotherapy agents and therefore contributes to the high mortality. To discover novel therapy options that can target recurrent disease, appropriate animal models that closely mimic the clinical profile of patients with recurrent ovarian cancer are required. The challenge in monitoring intra-peritoneal (i.p.) disease limits the use of i.p. models and thus most xenografts are established subcutaneously. We have developed a sensitive optical imaging platform that allows the detection and anatomical location of i.p. tumor mass. The platform includes the use of optical reporters that extend from the visible light range to near infrared, which in combination with 2-dimensional X-ray co-registration can provide anatomical location of molecular signals. Detection is significantly improved by the use of a rotation system that drives the animal to multiple angular positions for 360 degree imaging, allowing the identification of tumors that are not visible in single orientation. This platform provides a unique model to non-invasively monitor tumor growth and evaluate the efficacy of new therapies for the prevention or treatment of recurrent ovarian cancer.

We describe a non-invasive animal imaging platform that allows the detection, quantification, and monitoring of ovarian cancer growth and recurrence. This intra-peritoneal xenograft model mimics the clinical profile of patients with ovarian cancer.

小鼠模型的非侵入性成像检测和监测卵巢癌复发

Epithelial ovarian cancer is the most lethal gynecologic malignancy in the United States. Although patients initially respond to the current standard of ...

医学

High Spatial Resolution Chemical Imaging of Implant-Associated Infections with X-ray Excited Luminescence Chemical Imaging Through Tissue

Microbial infections associated with implantable medical devices are a major concern in fracture fixation failure. Early diagnosis of such infection will allow successful eradication with antibiotics without an extra cost for a second surgery. Herein, we describe XELCI as a technique with high X-ray resolution, implant specificity, and chemical sensitivity to noninvasively image chemical concentrations near the surface of implanted medical devices. The devices are coated with chemically reporting surfaces. This chemically responsive surface consists of two layers coated on an implantable medical device; a pH-sensitive layer (bromothymol blue or bromocresol green incorporated hydrogel) which is coated over a red-light emitting scintillator (Gd2O2S: Eu) layer for monitoring. A focused X-ray beam irradiates a spot on the implant, and the red light generated by the scintillator (with 620 nm and 700 nm peaks) is transmitted through the sensing layer which alters the spectral ratio depending on the pH. An image is generated by scanning the X-ray beam across the implant and measuring the spectral ratio of light passing through the tissue point-by-point. We used this imaging technique for monitoring implant-associated infections previously on the bone surface of the femur with a modified implantable plate sensor. Now we are studying pH changes that occur from tibial intramedullary rod infections. Two different types of intramedullary rod designs are used in pre-pilot rabbit studies, and we learned that the XELCI technique could be used to monitor any chemical changes that occur not only on the bone surface but also inside the bone. Thus, this enables noninvasive, high spatial resolution, low background local pH imaging to study implant-associated infection biochemistry.

Here, we present a protocol for high-resolution optical detection of chemical information around implanted medical devices with X-ray excited luminescence chemical imaging (XELCI). This novel imaging technique is developed in our lab which enables studying implant-associated infection biochemistry.

通过组织的X射线激发发光化学成像对植入物相关感染进行高空间分辨率化学成像

Microbial infections associated with implantable medical devices are a major concern in fracture fixation failure. Early diagnosis of such infection will ...

X-ray Fluorescence (XRF)

Source: Laboratory of Dr. Lydia Finney &#8212; Argonne National Laboratory
X-ray fluorescence is an induced, emitted radiation that can be used to generate spectroscopic information. X-ray fluorescence microscopy is a non-destructive imaging technique that uses the induced fluorescence emission of metals to identify and quantify their spatial distribution.