Bauters, Stephen

Beunis, Filip

Brans, Toon

Burghammer, Manfred

De Rijcke, Maarten

Garrevoet, Jan

Janssen, Colin

Vandegehuchte, Michiel

Vergucht, Eva

Vincze, Laszlo

Ghent University Academic Bibliography

 Eva VERGUCHT1*, Toon BRANS2,3, Filip BEUNIS2,3, Jan GARREVOET1, Maarten DE RIJCKE4,  Stephen BAUTERS1,5, Michiel VANDEGEHUCHTE4, Colin JANSSEN4, Manfred BURGHAMMER5,1 and Laszlo VINCZE1   1. X-ray Microspectroscopy and Imaging Group (XMI), Ghent University, Krijgslaan 281 (S12), B-9000 Ghent, Belgium  2. Department of Electronics and Information Systems (ELIS), Ghent University, Sint-Pietersnieuwstraat 41, B-9000 Ghent, Belgium 3. Center for Nano and Biophotonics (NB-Photonics), Ghent University, Sint-Pietersnieuwstraat 41, B-9000 Ghent, Belgium  4. Laboratory of Environmental Toxicology and Aquatic Ecology (GhEnToxLab), Ghent University, Jozef Plateaustraat 22, B-9000 Ghent, Belgium  5. European Synchrotron Radiation Facility (ESRF), 71 avenue des Martyrs, F-38043 Grenoble, France  In vivo X-ray fluorescence microimaging of biological model  organisms manipulated by laser-based optical tweezers Compact Optical Tweezers Setup  References Corresponding author [1]      Vincze, L., et al., Analytical Chemistry, 2004. 76(22): p. 6786-6791. [2]      Santucci, S.C., et al., Analytical Chemistry, 2011. 83(12): p. 4863-4870. [3]      Vergucht, E., et al., (Manuscript submitted). *  Eva Vergucht, X-ray Microspectroscopy and Imaging Group (XMI), Department of Analytical Chemistry,  Ghent University, Eva.Vergucht@UGent.be OT micro-XRF imaging at Microfocus beamline ID13 (ESRF)  Experimental conditions  Scrippsiella trochoidea microalgae  Exposed to elevated, toxic concentrations of transition metals  (Ni, Cu, Zn, 0-2700 µg/L, 96 h).  2.1010 photons/s at 13 keV, 0.5 s/pixel  Experimental results  Significant amounts of Mn, Fe, Cu and Zn are detected within reference samples, reflecting their essential nature in photosynthesis processes [3].  Inhomogenous subcellular bioaccumulation of Cu (675 µg/L).   Average scanning time of 5-10 minutes demonstrates  high-throughput potential of the OT XRF methodology.  Preservation of the structure of biological organisms is a major challenge when preparing biological samples for nano/micro XRF experiments.   Special need for delicate mounting of microscopic samples onto a support that does not interfere with the XRF measurement.   State-of-the-art and very expensive motor stages to perform accurate and precise XYZθ movements of the sample through the X-ray beam.  Organisms close to their natural, in vivo state  Free-standing samples in their natural, aqueous environment  Non-contact sample positioning and manipulation  Eliminate time-consuming and error prone sample preparation  Possibility of XRF tomography using multiple optical traps Current methodological challenges related to XRF imaging Proposed methodology for solving challenges  Optical tweezers for non-contact sample manipulation combined with Highly sensitive, multi-elemental micro-XRF imaging Motorized stages 5 Microscope trapping objective: • Focusses IR beam • 100x magnification, NA = 1 • Water immersion 6 Spatial Light Modulator (SLM): • Bi-functional: beam splitter or mirror • Computer-controlled via holograms 3 Mirrors (manipulated for alignment) 4 IR laser coupled with fiber optics: • λ = 1070 nm, transparent wavelength for biological samples 2 Start optical path (          ) 1 Incident  X-rays Olympus beamline microscope XYZ scanning stages Tilted (45°) VORTEX-EM detector (XRF) Mounted OT setup Confocal optic FReLoN CCD (SAXS) Quartz capillary with samples & medium (100 µm diameter, 10 µm wall thickness) 10 Aluminum sample holder 8 Quartz coverslip (100 µm thickness) 9 6 1 5 4 3 2 * Available from Microfocus beamline ID13, ESRF [2] Water droplet refill system 7 Conclusions and prospects We report on the radically new elemental imaging approach for the analysis of biological model organisms and single cells in their natural, in vivo state. The methodology combines optical tweezers (OT) technology for non-contact, laser-based sample manipulation with synchrotron radiation confocal XRF micro-imaging for the very first time. In future experiments, the possibilities of direct sample positioning and scanning using the SLM will be explored. Moreover, we propose ultra fast scans on a variety of biological organisms/single cells with a wide range of applications in all disciplines where in vivo, spatially resolved and highly sensitive multi-element analysis is of relevance on the microscopic scale. Introduction     Owing to its high sensitivity and non-destructive nature, synchrotron radiation (SR) based confocal X-Ray Fluorescence (XRF) imaging offers the unique potential of providing two- and three-dimensional information on the sample composition and elemental distributions with trace level detection limits [1]. With the increased availability of nanoscopic X-ray beams provided by 3rd generation SR sources, SR X-ray imaging methods pose important methodological challenges concerning sample preparation, non-contact sample manipulation and non-contact positioning. 5 7 8 Optically lifted microalgae 6 10 9 Si Ca Mn Fe Cu Zn scatter 50 µm top quartz capillary bottom capillary medium IR laser optically manipulated  microalgae 50 µm capillary zeolite 100 µm 500 µm (21  2 µm) (26  2 µm) 

In vivo X-ray fluorescence microimaging of biological model organisms manipulated by laser-based optical tweezers

https://biblio.ugent.be/publication/5848776/file/5848777

In vivo X-ray fluorescence microimaging of biological model organisms manipulated by laser-based optical tweezers

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Ghent University Academic Bibliography