Chemistry Colloquium
Ultrasensitive fluorescence-free analysis of nano-matter: from single proteins and viruses to sub-cellular features
Presented by Vahid Sandoghda, The Max Planck Institute
Hosted by Wei Min
The last two decades have demonstrated the insatiable potential of optical techniques for sensitive studies. Optical detection of small nanoparticles and single molecules have often relied on fluorescence, but limited photophysics and the need for labeling pose severe restrictions for the broad application of this approach. The ubiquitous process of Rayleigh scattering offers a powerful alternative. Although the common intuition might be that detection of individual nanoparticles and single molecules is not within reach via the measurement of their Rayleigh scattering, interferometric scattering (iSCAT) microscopy introduced in 2004 has demonstrated the contrary. Indeed, it is now possible to reach a remarkable real-time detection sensitivity down to single unlabeled proteins. In this presentation, I will present the most recent advances in iSCAT analysis, reaching an exquisite sensitivity for detecting single unlabeled bio-particles as light as 20 kDa. I also discuss new results in three-dimensional imaging and tracking of sub-cellular structures in live cells.
Vahid Sandoghdar is one of the pioneers of the field of Nano-Optics, which merges various methods and research areas to investigate fundamental issues in the interaction between light and matter at the nanometer scale. His current research ranges from quantum optics, plasmonics and ultrahigh resolution microscopy to nanobiophysics. Sandoghdar obtained his B.S. in physics from the University of California at Davis in 1987 and Ph.D. in physics from Yale University in 1993. After a postdoctoral stay at the Ecole Normale Supérieure in Paris, he moved to the University of Konstanz in Germany, where he started a new line of research to combine single molecule spectroscopy, scanning probe microscopy and quantum optics. In 2001, he became full professor at the Laboratory of Physical Chemistry at ETH in Zurich, Switzerland. In 2011, he became director at the Max Planck Institute for the Science of Light in Erlangen and Alexander von Humboldt Professor at the University of Erlangen-Nuremberg in Germany. Vahid Sandoghdar is the founder and spokesperson of the newly established Max-Planck-Zentrum für Physik und Medizin, a joint research center that addresses questions in fundamental medical research with physical and mathematical methods.
