10th Karl Friedrich Bonhoeffer Lecture: "Single nano-objects in the spotlight"

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02/08/2007 - 02/08/2007 | Göttingen

10th Karl Friedrich Bonhoeffer Lecture: "Single nano-objects in the spotlight"

The next "Karl Friedrich Bonhoeffer Lecture" at the Max Planck Institute for Biophysical Chemistry will be given by Prof. Michael Orrit, Molecular Nano-Optics and Spins, Leiden Institute of Physics, Leiden University, The Netherlands. The title is "Single nano-objects in the spotlight". Thursday February 8, 2007 at 5 p.m.

The lecture series in the memory of Karl Friedrich Bonhoeffer (1899-1957) has been established in 2004. K.F. Bonhoeffer was one of the first physical chemists who had practised an multi-disciplinary approach in natural sciences and had systematically applied physico-chemical methods in solving biological problems. To strengthen such multi-disciplinary approaches in current research, and to honour K.F. Bonhoeffer, the new lecture series was founded. It intends to attract scientists from all nearby research areas. The lectures are open not only to members of the MPI but also to colleagues of other institutes and to the public. Lectures will be given in English.

Prof. Dr. Michael Orrit
Molecular Nano-Optics and Spins, Leiden Institute of Physics, Leiden University,
The Netherlands
"Single nano-objects in the spotlight"

The optical selection of individual nano-objects (molecules or nanoparticles) in a far-field microscope has several advantages with respect to more established single-molecule methods, such as electron microscopy or scanning probe microscopies. Laser excitation often is non-invasive and commands a wide range of time-resolved and frequency-resolved spectroscopic techniques. I shall illustrate the methods of single-molecule optics with two recent topics from our group.
i) We studied the time-resolved absorption of single gold nanoparticles by interferometry, and detected acoustic oscillations launched by an intense pump pulse. This opens up a new field of nano-mechanics, which combines picosecond temporal resolution with nanometer spatial resolution.
ii) We probed the approach of the glass transition in a supercooled molecular liquid by following the rotational diffusion of single fluorescent molecules (see Fig.). We found large differences in local viscosity, with exceedingly long memory times, days or longer. We associate this heterogeneity of the supercooled liquid to a solid structure, present already 30 K above the glass transition temperature. Recent macroscopic rheology experiments confirm that the solid-like structure confers many of the well-known attributes of soft glassy rheology (yield-stress, shear-thinning, aging,...) to supercooled glycerol. The shear modulus of the material changes by more than two orders of magnitude upon aging two weeks at 205 K.
Experiments on single nano-objects demonstrate the power of local observations at nanometer scales. They reveal unexpected and previously unobserved properties, throwing new light even onto such long-standing questions as the glass transition.

http://www.mpibpc.mpg.de/service/pr-office/events/KFB_Lecture/index.html
http://www.mpibpc.mpg.de/groups/pr/PR/2007/07_03/ (German)
http://www.mpibpc.mpg.de/groups/pr/PR/2007/07_03/index_en.html (English)

Information on participating / attending:

Date:

02/08/2007 17:00 - 02/08/2007 18:00

Event venue:

Manfred-Eigen-Hörsaal
Max-Planck-Institute für biophysikalische Chemie
Göttingen
Am Fassberg 11
37077 Göttingen
Niedersachsen
Germany

Target group:

all interested persons

Relevance:

local

Subject areas:

Biology, Chemistry, Information technology, Mathematics, Medicine, Nutrition / healthcare / nursing, Physics / astronomy

Types of events:

Entry:

02/01/2007

Sender/author:

Dr. Christoph Nothdurft

Department:

Presse- und Öffentlichkeitsarbeit

Max-Planck-Institut für biophysikalische Chemie

Event is free:

yes

Language of the text:

English

URL of this event: http://idw-online.de/en/event19400