Speaker
Dr
Karolina Stachnik
(Universität Hamburg, Center for Free-Electron Laser Science)
Description
Structural investigations of biological systems often involve the application of several highly sensitive and complementary methods able to provide statistically significant results. X-ray ptychography [1] is a robust and promising scanning coherent-diffraction imaging technique, yielding quantitative optical density contrast at dose-limited spatial resolutions beyond the fabrication limits of X-ray optics. Its scanning nature allows for simultaneous X-ray fluorescence (XRF) mapping, that enables artefact-free correlations of trace elements with highly resolved specimen’s morphology [2,3]. Moreover, ptychography can also be combined with computed tomography, yielding quantitative 3D electron-density maps of extended specimens down to sub-100-nm spatial resolutions [4]. Thanks to its sensitivity, ptychography is particularly suitable for imaging biological tissues and cells, whose irradiation sensitivity sets a stringent requirement for highly efficient use of every X-ray photon they interact with. By using high-quality coherent X-ray beams, low-background setups, and optimized scanning routines, multimodal scanning X-ray microscopy aspires to an excellent tool for high-resolution structural investigations of weakly absorbing sub-cellular structures in 3D.
Here, we present the application of ptychography with concurrent XRF mapping at beamline P11 at the low-emittance synchrotron storage ring PETRA III, DESY. We developed a scanning X-ray microscope featuring a Fresnel zone plate as an illumination-forming optic, high-throughput scanning unit, and a high-framerate detector. We used the correlative method to image a population of macrophages treated with iron-oxide nanocontainers for tuberculosis drugs. We further applied the concurrent imaging techniques to study the mineralization of a human bone matrix [5]. Recently, we have upgraded our X-ray microscope with a rotation stage permitting ultrafast tomographic measurements. We will demonstrate its operation with ptychographic tomograms of representative specimens. Finally, further applications, in reference to emerging diffraction-limited synchrotron light sources, will be addressed.
References
1. F. Pfeiffer, Nature Photonics, 12(1), 9 (2018).
2. D.J. Vine, D. Pelliccia, C. Holzner, S.B. Baines, A. Berry, I. McNulty, S. Vogt, A.G. Peele, and K.A. Nugent, Opt. Express 20(16), 18287 (2012).
3. J. Deng, D.J. Vine, S. Chen, Y.S.G. Nashed, Q. Jin, N.W. Phillips, T. Peterka, R. Ross, S. Vogt, and C.J. Jacobsen, PNAS 112(8), 2314 (2015).
4. M. Dierolf, A. Menzel, P. Thibault, P. Schneider, C. M. Kewish, R. Wepf, O. Bunk, and F. Pfeiffer, Nature 467(7314), 436 (2010).
5. K. Stachnik, M. Warmer, I. Mohacsi, V. Hennicke, P. Fischer, J. Meyer, T. Spitzbart, M. Barthelmess, J. Eich, C. David, C. Feldmann, B. Busse, K. Jähn, U. E. Schaible, and A. Meents, Sci. Reports, 10(1784) (2020).
Primary authors
Dr
Alke Meents
(DESY)
Dr
Karolina Stachnik
(Universität Hamburg, Center for Free-Electron Laser Science)
Co-authors
Dr
Christian David
(Paul Scherrer Institut, Switzerland)
Dr
Istvan Mohacsi
(European XFEL)
Mr
Jan Meyer
(DESY)
Dr
Katharina Jähn
(Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany)
Dr
Mauro Prasciolu
(DESY)
Miriam Barthelmess
(CFEL)
Mr
Pontus Fischer
(Center for Free-Electron Laser Science, DESY)
Dr
Saša Bajt
(Center for Free-Electron Laser Science, DESY)
Prof.
Ulrich E. Schaible
(Research Center Borstel – Leibniz Lung Center, Germany)
Mr
Vincent Hennicke
(Center for Free-Electron Laser Science, DESY)
