The Power of SAXS: Exploration of the Magic World of
Bio- and Nanomaterials
Michael Rappolt
School of Food Science and NutritionFACULTY OF MATHEMATICS AND PHYSICAL SCIENCES
2. BSc Student Lecture: Physics with Introduction to Modern Physics
2nd of June 2014, Faculty of Electrical Engineering, University of Ljubljana
Interaction of X-rays with Matter
e-
e-
e-
e-
e-
e-
e-Transmission
e- photoelectron
e-
e-
e-
e-
e-
e- e-
Absorption
e-
Fluorescence
Interaction of X-rays with Matter (cont.)
e-
e-
e-
e-
e-
e-
e-
e-
Scattering
Elastic Scattering: hν’ = hν (Thomson)
Inelastic Scattering: hν’ < hν (Compton)
e-
e-
e-
e-
e-
e-
e-
e-
Pair Production E = hν > 1 MeV*
e-
e+
*1 eV = 1.602 10-19 J
The Austrian SAXS Beamline
light-source:Sincrotone Trieste
monochromator for 5.4, 8 and 16 keV
sample
X-ray pattern
toroidal mirror:focal spot size
1.2 x 0.6 mm2 (FWHM)
variable
sample
area
camera length: Up to 5 m
SAXS Methods
Solution Scattering:
Formation of CaCO3; Proteins
Fiber-Diffraction:
Discovery of DNA; Collagen
Small Angle X-ray Diffraction:
Liquid Crystal Membranes
Grazing Incidence X-ray Scattering:
Membrane Fusion; Quantum Dots
Rosalind Franklin's X-ray diffraction photograph of DNA, 1953
Diffuse scattering of water
Powder diffraction on lipid/water systems
Surface Diffraction
Solution Scattering: Diluted Systems
3
RqexpVpqI
2
g
2
p
2Guinier Approximation (qR<<1):
Scattering function of monodisperse spheres
4qP
.constqI Porod Approximation (qR>>1):VS
pP 2
X-ray
ki
kfq
I(q)
Fast Chemical Reactions in a Free Standing Jet
Na2CO3 + CaCl2 → CaCO3 + 2NaCl
Concentration of reagents: 50 mM
Free jet micromixer to study sub 100 s chemical and biological reactions
•Time of first accessible measurement 75 µs
•The evolution of the chemical reaction is detected: volume fraction increasing
Marmiroli, B., G. Grenci, F. Cacho-Nerin, B. Sartori, E. Ferrari, P. Laggner, L. Businaro and H. Amenitsch, Lab Chip, 9, 2063-2069 (2009)
Shape Analysis of Proteins
M. Hammel, M. Kriechbaum, A. Gries, G.H. Kostner, P. Laggner & R. Prassl 2002 JMB 321, 85.
from crystal structure of b2GPI
shape reconstruction and rigid body refinement
crystalsolution
Discovery of the DNA-Structure
Rosalind Franklin's X-ray diffraction photograph of DNA
Watson and Crick in front of their DNA model, 1953
In-Situ Testing of Human Aortas: the Set-up
X-rays
Markers forvideo
extensometer
Total force recorded via load cells
Load protocols:– Uniaxial– Equibiaxial– Strip – biaxial
In-Situ Testing of Human Aortas: Conclusion
Uniaxial
Biaxial
Strip biaxial
Uniaxial
Strip biaxial
λC
λL
Equi-biaxial
Uniaxial UniaxialStrip
biaxialStrip
biaxial
Schmid, F., Sommer, G., Rappolt, M., Schulze-Bauer, C.A.J., Regitnig, P., Holzapfel, G.A., Laggner, P., and Amenitsch, H. (2005) J. Synchrotron Rad. 12: 727-733.
SAXD: Polymorphism of Lipid Liquid Crystals
H2
tem
pera
ture
I2
V2
La
additive
37 C
low
h
igh
Yaghmur, A., and Rappolt, M. (2011): Recent advances in the characterization of lipid-based nanocarriers. In: Nanotechnologies for Solubilization and Delivery in Foods, Cosmetics and Pharmaceuticals, Nissim Garti and Ididt Yuli-Amar (eds.), DEStech Publication Inc., Lancaster, pp. 187-208.
Characterizing Quantum Dots with GISAXS
Simulation of a GISAXS pattern obtained for a 3nm thick deposit of Pd on MgO(100)@700K.
D
GISAXD: Membrane Fusion Caught in the Act
L. Yang, H.W. Huang, Science 297 (2002) 1877.
M. Rappolt, H. Amenitsch, S. Strancar, C.V. Teixeira, M. Kriechbaum, G. Pabst, M. Majerowicz & P. Laggner, P. (2004) Colloid Interface Sciences 111: 63-77.