Humboldt Fellow new addition to Aziz team
Dr. Tristan Petit joins the Aziz-Team. Foto: T.Petit
Simulated view of a nanodiamond. © T. Petit
Starting June 1st, Dr. Tristan Petit will be joining Prof. Dr. Emad Flear Aziz’ team for a two-year postdoc. His Humboldt Foundation Fellowship for Postdoctoral Researchers gave Petit the option to choose his German scientific host. Ultimately, he decided on the Joint Ultrafast Dynamics Lab in Solutions and at Interfaces (JULiq) that was set up by Aziz. Says Petit: “I really wanted to be on Aziz’ team as they have a lot of collective expertise with spectroscopy in water.”
26-year-old Tristan Petit earned his Ph.D. degree at the Ecole Normale Supérieure de Cachan, France, back in March of this year. His doctoral work at the Diamond Sensors Laboratory (CEA), Gif-sur-Yvette, focused on nanodiamond surface modifications to evaluate their biomedical potential. Nanodiamonds could make good “drug cabs” as they have low toxicity and their surfaces can be easily functionalized for the transport of other molecules.
Although to date, the interactions between water molecules and nanoparticles remain unclear. Petit has made it his mission to get to the bottom of these interactions: He is planning on using soft X-ray spectroscopy to study water-based dispersions of nanodiamonds “in situ” on a microjet. This may provide important clues about how these special nanoparticles behave under physiological conditions, in other words, in the body. “Thanks to the unique Lixedrom experimental setup, we’re able to conduct experiments that can’t be done anywhere else really. Ultimately, that was a strong motivating factor for me to come to Berlin,” admits Petit.
- BESSY II: Phosphorous chains – a 1D material with 1D electronic propertiesFor the first time, a team at BESSY II has succeeded in demonstrating the one-dimensional electronic properties of a material through a highly refined experimental process. The samples consisted of short chains of phosphorus atoms that self-organise at specific angles on a silver substrate. Through sophisticated analysis, the team was able to disentangle the contributions of these differently aligned chains. This revealed that the electronic properties of each chain are indeed one-dimensional. Calculations predict an exciting phase transition to be expected as soon as these chains are more closely packed. While material consisting of individual chains with longer distances is semiconducting, a very dense chain structure would be metallic.
- Did marine life in the palaeocene use a compass?Some ancient marine organisms produced mysterious magnetic particles of unusually large size, which can now be found as fossils in marine sediments. An international team has succeeded in mapping the magnetic domains on one of such ‘giant magnetofossils’ using a sophisticated method at the Diamond X-ray source. Their analysis shows that these particles could have allowed these organisms to sense tiny variations in both the direction and intensity of the Earth’s magnetic field, enabling them to geolocate themselves and navigate across the ocean. The method offers a powerful tool for magnetically testing whether putative biological iron oxide particles in Mars samples have a biogenic origin.
- What vibrating molecules might reveal about cell biologyInfrared vibrational spectroscopy at BESSY II can be used to create high-resolution maps of molecules inside live cells and cell organelles in native aqueous environment, according to a new study by a team from HZB and Humboldt University in Berlin. Nano-IR spectroscopy with s-SNOM at the IRIS beamline is now suitable for examining tiny biological samples in liquid medium in the nanometre range and generating infrared images of molecular vibrations with nanometre resolution. It is even possible to obtain 3D information. To test the method, the team grew fibroblasts on a highly transparent SiC membrane and examined them in vivo. This method will provide new insights into cell biology.