November 27, 2012
Smallest Biomarkers Tracked Down
Physikalisch-Technische Bundesanstalt (PTB)
PTB and Dectris have developed a vacuum-compatible X-ray detector that allows the size of low-contrast nano-objects to be determined.
What makes this detector unique is the size of its total surface (17 cm Ã 18 cm) as well as the fact that it can be operated in vacuum. Operating the detector in vacuum drastically increases the sensitivity of the measuring facility, since the soft X-rays, which are scattered on the sample, are not absorbed by air molecules on their way towards the detector. This device now allows, for example, experiments for size determination of nanoparticles to be carried out with small-angle X-ray scattering (SAXS) also at the absorption edges of the light elements calcium, sulphur, phosphor or silicon at photon energies below 5 keV with high dynamics and good spatial resolution.
For a few months, the new Pilatus X-ray detector has been used for some of PTB's own research projects. At the synchrotron radiation source BESSY II in Berlin-Adlershof, where PTB has been operating its own laboratory for 15 years, scientists are now using the new detector, for example, to establish the - urgently needed - metrological basis for the size determination of microvesicles. A project carried out within the scope of the European Metrology Research Programme (EMRP) and with the significant participation of the Amsterdam Medical Center in the Netherlands is to contribute decisively to fully exploiting the potential of microvesicles for the early diagnosis of diseases
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