Dream Chemistry Lectures series


    Dr. Thomas Juffmann
Max F.Perutz Laboratories, University of Vienna, Austria

"Research and Education in Molecular Biology"

21 February 2019, 10:00
Abstract:
Optical phase contrast microscopy and cryo-electron microscopy are widely used in the study of cells and proteins, respectively. In both techniques, a specimen imparts a phase shift on the probe (photons or electrons), which can be measured using various interferometric techniques.
In this talk I will briefly discuss the physical basics and limits of phase microscopy, and will show ways how to improve on current techniques using wave-front shaping, cavity or quantum enhanced measurements. I will demonstrate how wave-front shaping can enable phase contrast imaging with optimized sensitivity all across the field of view, and how multi-passing the probe particles through a sample can be used for high sensitivity / low damage imaging. The latter could potentially allow for cryo-electron microscopy with unprecedented resolution.

 

    Prof. Dr. Pablo Rivera-Fuentes
Dept of Chemistry and Applied Bioscences, ETH Zürich, Switzerland

"Chemical tools for single-molecule imaging in live cells"

7 February 2019, 10:00
Abstract:
Single-molecule imaging enables the observation of cellular structures with nanometric resolution. In densely labeled samples, however, emission from molecules that are closer than the diffraction limit of light appear as a single signal. To enable the localization of such molecules beyond the diffraction limit, photoactivatable or photoswitchable dyes have been developed. In recent work, we extended this concept to combine photoactivation and other chemical processes to tackle some of the current challenges in single-molecule imaging. For example, we have developed probes that enable the observation of single molecules of enzymes based on their activity. We have also created fluorophores with a polarity-dependent photoactivation mechanism, allowing to image intracellular lipid domains with nanometric resolution. Moreover, dyes that combine photoactivation and fluxional equilibria have allowed us to perform very long time-lapse, super-resolved imaging of synaptic vesicles in live human neurons with minimal phototoxicity or photobleaching. These experiments have revealed details of the 3D compartmentalization of these vesicles.

 

    Dr. David Martinez-Martin
Dept of Biosystems Science and Engineering, ETH Zürich, Switzerland

"Tracking a cell's mass in real time: a new indicator of cell physiology"

24 January 2019
Biography

  • Bachelor’s + Master’s degree in Physics (2005). University of Valladolid (Spain). Summa Cum Laude
  • PhD in Physics (2011). Autonomous University of Madrid (Spain). Summa Cum Laude
  • Postdoctoral EMBO Fellowship. ETH Zurich (2013-2015)
  • Scientist and Project Manager. ETH Zurich (2016-currently)
  • Senior Lecturer. University of Sydney (offer accepted)
  • Selected achievement: Technology to measure mass changes of a single living cell in real time.
 

    Dr. Dominik Kubicki
Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland

"How Physical Chemistry advances Materials Science: solid-state NMR of lead halide perovskites for optoelectronics"

19 December 2018
Abstract:
Organic-inorganic lead halide perovskites are a promising family of light absorbers for a new generation of LEDs and solar cells, with reported efficiencies currently exceeding 22%. The field of perovskite photovoltaics is largely driven by systematic optimization of numerous parameters affecting the performance of perovskite solar cells. Such a trial-and-error approach, not backed up by atomic-level understanding of the reasons behind successes and failures, makes rational design of new compositions with better properties extremely difficult. Here, I will show how we use high-field multi-nuclear (1H, 2H, 13C, 14N, 15N, 133Cs, 87Rb, 39K) solid-state magic angle spinning NMR to provide for the first time atomic-level understanding of the different doping strategies used to improve photovoltaic performance of lead halide perovskites. These advances were largely enabled by a new solid-state method of synthesizing highly pure and crystalline lead halide perovskites: mechanosynthesis.