X-ray absorption spectroscopy and its application: X-ray fluorescene imaging

Dramatic advances in the understanding of X-ray absorption fine structure (XAFS) have been made over the past few decades, which have led ultimately to a highly quantitative theory. X-ray absorption fine structure (XAFS) refers to the oscillatory structure in the x-ray absorption coefficient just above an x-ray absorption edge. This turns out to be a unique signature of a given material; it also depends on the detailed atomic structure and electronic and vibrational properties of the material. Transmission and fluorescence XAFS have been widely used and essential to progress in many scientific fields like biology, chemistry, electronics, geophysics, metallurgy, or materials science. XAFS provides subatomic resolution and is suitable for various samples environment compared with crystallography. With the technical improvement of SR-XAS beamline over last decade, it become possible to conduct X-ray fluorescence mapping with biological sample.  X-ray fluorescence mapping (XFM) offers multi-elemental detection with lateral resolution down to the tens of nm, in combination with spatially resolved X-ray absorption spectroscopy (XAS)speciation. Recently, the researchers from University of Saskatchewan imaged the distribution of sulfur with different chemical forms in biological samples, such as zebrafish cartilage.   

1. H. A. Castillo-Michel, C. Larue, A. E. Pradas Del Real, M. Cotte and G. Sarret, Plant Physiol Biochem 2017, 110, 13-32.
2. P. A. Lee, P. H. Citrin, P. Eisenberger and B. M. Kincaid, Reviews of Modern Physics 1981, 53, 769-806.
3. M. J. Hackett, P. G. Paterson, I. J. Pickering and G. N. George, Anal Chem 2016, 88, 10916-10924.
4. A. Gaur and B. D. Shrivastava, Review Journal of Chemistry 2015, 5, 361-398.