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Swaraj S, Belkhou R, Stanescu S, Rioult M, Besson A, Hitchcock AP. Performance of the HERMES beamline at the carbon K-edge. ACTA ACUST UNITED AC 2017. [DOI: 10.1088/1742-6596/849/1/012046] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Karunakaran C, Christensen CR, Gaillard C, Lahlali R, Blair LM, Perumal V, Miller SS, Hitchcock AP. Introduction of soft X-ray spectromicroscopy as an advanced technique for plant biopolymers research. PLoS One 2015; 10:e0122959. [PMID: 25811457 PMCID: PMC4374829 DOI: 10.1371/journal.pone.0122959] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 02/16/2015] [Indexed: 12/02/2022] Open
Abstract
Soft X-ray absorption spectroscopy coupled with nano-scale microscopy has been widely used in material science, environmental science, and physical sciences. In this work, the advantages of soft X-ray absorption spectromicroscopy for plant biopolymer research were demonstrated by determining the chemical sensitivity of the technique to identify common plant biopolymers and to map the distributions of biopolymers in plant samples. The chemical sensitivity of soft X-ray spectroscopy to study biopolymers was determined by recording the spectra of common plant biopolymers using soft X-ray and Fourier Transform mid Infrared (FT-IR) spectroscopy techniques. The soft X-ray spectra of lignin, cellulose, and polygalacturonic acid have distinct spectral features. However, there were no distinct differences between cellulose and hemicellulose spectra. Mid infrared spectra of all biopolymers were unique and there were differences between the spectra of water soluble and insoluble xylans. The advantage of nano-scale spatial resolution exploited using soft X-ray spectromicroscopy for plant biopolymer research was demonstrated by mapping plant cell wall biopolymers in a lentil stem section and compared with the FT-IR spectromicroscopy data from the same sample. The soft X-ray spectromicroscopy enables mapping of biopolymers at the sub-cellular (~30 nm) resolution whereas, the limited spatial resolution in the micron scale range in the FT-IR spectromicroscopy made it difficult to identify the localized distribution of biopolymers. The advantages and limitations of soft X-ray and FT-IR spectromicroscopy techniques for biopolymer research are also discussed.
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Affiliation(s)
- Chithra Karunakaran
- Canadian Light Source Inc., 44 Innovation Boulevard, Saskatoon, Saskatchewan, Canada
- * E-mail:
| | - Colleen R. Christensen
- Industrial Research Assistance Program—National Research Council Canada, 110 Gymnasium Place, Saskatoon, Saskatchewan, Canada
| | - Cedric Gaillard
- INRA—Biopolymers, Interactions, Assemblies Unit (BIA), Nantes, France
| | - Rachid Lahlali
- Canadian Light Source Inc., 44 Innovation Boulevard, Saskatoon, Saskatchewan, Canada
| | - Lisa M. Blair
- Canadian Light Source Inc., 44 Innovation Boulevard, Saskatoon, Saskatchewan, Canada
- Canadian Food Inspection Agency, 116 Veterinary Road, Saskatoon, Saskatchewan, Canada
| | - Vijayan Perumal
- Canadian Light Source Inc., 44 Innovation Boulevard, Saskatoon, Saskatchewan, Canada
| | - Shea S. Miller
- Agriculture and Agri-Food Canada, Eastern Cereal and Oilseed Research Centre, Ottawa, Ontario, Canada
| | - Adam P. Hitchcock
- Brockhouse Institute for Materials Research, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada
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Tizei LHG, Liu Z, Koshino M, Iizumi Y, Okazaki T, Suenaga K. Single molecular spectroscopy: identification of individual fullerene molecules. PHYSICAL REVIEW LETTERS 2014; 113:185502. [PMID: 25396379 DOI: 10.1103/physrevlett.113.185502] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Indexed: 06/04/2023]
Abstract
We report the molecule-by-molecule spectroscopy of individual fullerenes by means of electron spectroscopy based on scanning transmission electron microscopy. Electron energy-loss fine structure analysis of carbon 1s absorption spectra is used to discriminate carbon allotropes with known symmetries. C(60) and C(70) molecules randomly stored inside carbon nanotubes are successfully identified at a single-molecular basis. We show that a single molecule impurity is detectable, allowing the recognition of an unexpected contaminant molecule with a different symmetry. Molecules inside carbon nanotubes thus preserve their intact molecular symmetry. In contrast, molecules anchored at or sandwiched between atomic BN layers show spectral modifications possibly due to a largely degraded structural symmetry. Moreover, by comparing the spectrum from a single C(60) molecule and its molecular crystal, we find hints of the influence of solid-state effects on its electronic structure.
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Affiliation(s)
- Luiz H G Tizei
- Nanotube Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8565, Japan
| | - Zheng Liu
- Nanotube Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8565, Japan
| | - Masanori Koshino
- Nanotube Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8565, Japan
| | - Yoko Iizumi
- Nanotube Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8565, Japan
| | - Toshiya Okazaki
- Nanotube Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8565, Japan
| | - Kazu Suenaga
- Nanotube Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8565, Japan
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Araki T, Hitchcock AP, Shen F, Chang PL, Wang M, Childs RF. Quantitative chemical mapping of sodium acrylate- and N-vinylpyrrolidone-enhanced alginate microcapsules. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2012; 16:611-27. [PMID: 16001720 DOI: 10.1163/1568562053783687] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Alginate microcapsules enclosing recombinant cells secreting therapeutic products have been used successfully to treat several murine models of human diseases. The mechanical and chemical properties of these alginate capsules can be improved by the addition and in situ photo-polymerization of sodium acrylate and N-vinylpyrrolidone in the alginate capsule. The purpose of this modification was to form additional covalent cross-links. In this work we have used scanning transmission X-ray microscopy (STXM) to probe the nature and location of the chemical modifications in the modified capsules by comparison with unmodified capsules. Analysis of X-ray image sequences and selected area spectra has been used to map the calcium gradient in capsules, to identify the presence of polyacrylate throughout the capsules and the localization of poly-N-vinylpyrrolidone in the outer regions of the alginate capsules. The differences in the spatial distributions of these species have led to better understanding of the chemical modifications that provide a mechanically more stable capsule structure.
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Affiliation(s)
- Tohru Araki
- Department of Chemistry, McMaster University, Hamilton, Ontario, Canada
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Beckers M, Senkbeil T, Gorniak T, Reese M, Giewekemeyer K, Gleber SC, Salditt T, Rosenhahn A. Chemical contrast in soft x-ray ptychography. PHYSICAL REVIEW LETTERS 2011; 107:208101. [PMID: 22181778 DOI: 10.1103/physrevlett.107.208101] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Indexed: 05/31/2023]
Abstract
The unique strengths of x-ray microscopy are high penetration depth and near-edge resonances that provide chemical information. We use ptychography, a coherent diffractive imaging technique that disposes of the requirement for isolated specimens, and demonstrate resonant imaging by exploiting resonances near the oxygen K edge to differentiate between two oxygen-containing materials. To highlight a biological system where resonant ptychography might be used for chemical mapping of unsliced cells, reconstructions of freeze-dried Deinococcus radiodurans cells at an energy of 517 eV are shown.
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Affiliation(s)
- Mike Beckers
- Applied Physical Chemistry, Ruprecht-Karls-University Heidelberg, Germany.
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Leung BO, Brash JL, Hitchcock AP. Characterization of Biomaterials by Soft X-Ray Spectromicroscopy. MATERIALS (BASEL, SWITZERLAND) 2010; 3:3911-3938. [PMID: 28883316 PMCID: PMC5445794 DOI: 10.3390/ma3073911] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2010] [Accepted: 07/05/2010] [Indexed: 11/16/2022]
Abstract
Synchrotron-based soft X-ray spectromicroscopy techniques are emerging as useful tools to characterize potentially biocompatible materials and to probe protein interactions with model biomaterial surfaces. Simultaneous quantitative chemical analysis of the near surface region of the candidate biomaterial, and adsorbed proteins, peptides or other biological species can be obtained at high spatial resolution via scanning transmission X-ray microscopy (STXM) and X-ray photoemission electron microscopy (X-PEEM). Both techniques use near-edge X-ray absorption fine structure (NEXAFS) spectral contrast for chemical identification and quantitation. The capabilities of STXM and X-PEEM for the analysis of biomaterials are reviewed and illustrated by three recent studies: (1) characterization of hydrophobic surfaces, including adsorption of fibrinogen (Fg) or human serum albumin (HSA) to hydrophobic polymeric thin films, (2) studies of HSA adsorption to biodegradable or potentially biocompatible polymers, and (3) studies of biomaterials under fully hydrated conditions. Other recent applications of STXM and X-PEEM to biomaterials are also reviewed.
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Affiliation(s)
- Bonnie O Leung
- Department of Chemistry & Chemical Biology, McMaster University, Hamilton, ON, L8S 4M, Canada.
| | - John L Brash
- School of Biomedical Engineering, McMaster University, Hamilton, ON, L8S4M1, Canada.
| | - Adam P Hitchcock
- Department of Chemistry & Chemical Biology, McMaster University, Hamilton, ON, L8S 4M, Canada.
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Hub C, Wenzel S, Raabe J, Ade H, Fink RH. Surface sensitivity in scanning transmission x-ray microspectroscopy using secondary electron detection. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2010; 81:033704. [PMID: 20370182 DOI: 10.1063/1.3360813] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The successful integration of electron detection into an existing scanning transmission x-ray microspectroscope (STXM) at the Swiss Light Source is demonstrated. In conventional x-ray detection using a photomultiplier, STXM offers mainly bulk sensitivity combined with high lateral resolution. However, by implementation of a channeltron electron multiplier, the surface sensitivity can be established by the detection of secondary electrons emitted from the sample upon resonant excitation. We describe the experimental setup and discuss several relevant aspects, in particular the schemes to correct for self-absorption in the specimen due to back illumination in case of thicker films.
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Affiliation(s)
- C Hub
- Physikalische Chemie II and ICMM, Universität Erlangen-Nürnberg, 91058 Erlangen, Germany
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NEXAFS microscopy and resonant scattering: Composition and orientation probed in real and reciprocal space. POLYMER 2008. [DOI: 10.1016/j.polymer.2007.10.030] [Citation(s) in RCA: 239] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Urquhart SG, Gillies R. Matrix effects in the carbon 1s near edge x-ray absorption fine structure spectra of condensed alkanes. J Chem Phys 2006; 124:234704. [PMID: 16821938 DOI: 10.1063/1.2206589] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The carbon 1s near edge x-ray absorption fine structure (NEXAFS) spectra of simple gaseous alkane molecules differ from the spectra of the same alkane molecules in the condensed phase. The origin of these large, systematic differences is poorly understood. The NEXAFS spectra of gaseous alkanes are interpreted as a progression of core-->Rydberg transitions with distinctive vibronic structure. The interpretation of the NEXAFS spectra of condensed phase alkanes is varied. Specifically, the degree of Rydberg character in the pre-edge core excited states of condensed alkanes is controversial. We determined the character of core excited states in condensed alkanes with a combination of experiment and computational study. From this, we have determined the nature of matrix effects for these species. The high-resolution carbon 1s NEXAFS spectrum of gaseous neopentane is dramatically different from its condensed phase spectrum, a striking illustration of the dramatic spectroscopic changes that occur upon condensation. High quality ab initio calculations of a cluster designed to model the solid phase environment provide definitive evidence for the reduction of Rydberg character and support the assignment of sigma*C-H) valence character in the pre-edge features in the NEXAFS spectra of condensed alkanes.
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Affiliation(s)
- Stephen G Urquhart
- Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, SK S7N 5C9, Canada.
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Hitchcock AP, Stöver HDH, Croll LM, Childs RF. Chemical Mapping of Polymer Microstructure Using Soft X-ray Spectromicroscopy. Aust J Chem 2005. [DOI: 10.1071/ch05054] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Recently, synchrotron-based soft X-ray spectromicroscopy techniques have been applied to studies of polymer microstructure at the ~50 nm spatial scale. Functional group based chemical speciation and quantitative mapping is provided by near edge X-ray absorption fine structure spectral (NEXAFS) contrast. The techniques, sample data, and analysis methods of scanning transmission X-ray microscopy (STXM) and X-ray photoemission electron microscopy (X-PEEM) are outlined. The capabilities of STXM are illustrated by results from recent studies of (a) controlled release microcapsules and microspheres, (b) microcapsules being developed for gene therapy applications, (c) conducting polymer films studied in the presence of electrolyte and under potential control, and (d) studies of protein interactions with patterned polymer surfaces. In the latter area, the capabilities of STXM and X-PEEM are compared directly.
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Hitchcock AP, Morin C, Heng YM, Cornelius RM, Brash JL. Towards practical soft X-ray spectromicroscopy of biomaterials. JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 2003; 13:919-37. [PMID: 12463511 DOI: 10.1163/156856202320401960] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Scanning transmission X-ray microscopy (STXM) is being developed as a new tool to study the surface chemical morphology and biointeractions of candidate biomaterials with emphasis on blood compatible polymers. STXM is a synchrotron based technique which provides quantitative chemical mapping at a spatial resolution of 50 nm. Chemical speciation is provided by the near edge X-ray absorption spectral (NEXAFS) signal. We show that STXM can detect proteins on soft X-ray transparent polymer thin films with monolayer sensitivity. Of great significance is the fact that measurements can be made in situ, i.e. in the presence of an overlayer of the protein solution. The strengths, limitations and future potential of STXM for studies of biomaterials are discussed.
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Affiliation(s)
- A P Hitchcock
- Brockhouse Institute for Materials Research, McMaster University, Hamilton, ON, Canada, L8S 4MI.
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Koprinarov IN, Hitchcock AP, McCrory CT, Childs RF. Quantitative Mapping of Structured Polymeric Systems Using Singular Value Decomposition Analysis of Soft X-ray Images. J Phys Chem B 2002. [DOI: 10.1021/jp013281l] [Citation(s) in RCA: 126] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- I. N. Koprinarov
- Department of Chemistry, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - A. P. Hitchcock
- Department of Chemistry, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - C. T. McCrory
- Department of Chemistry, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - R. F. Childs
- Department of Chemistry, McMaster University, Hamilton, Ontario L8S 4M1, Canada
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