Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Chirality in 'real-time'

11.01.2019

In nature, certain molecules with the same chemical composition, can exist in two different shapes that are mirrors images of each other, much like our hands. This property is known as "chirality" and molecules with different chirality are called enantiomers. Enantiomers can exhibit entirely different chemical or biological properties, and separating them is a major issue in drug development and in medicine.

The method commonly used to detect enantiomers is circular dichroism (CD) spectroscopy. It exploits the fact that light polarized into a circular wave (like a whirlpool) is absorbed differently by left-handed and right-handed enantiomers. Steady-state CD spectroscopy is a major structural tool in (bio)chemical analysis.


An illustration of chirality in a molecule.

Credit: M. Oppermann, EPFL

During their function, biomolecules undergo structural changes that affect their chiral properties. Probing these in real-time (i.e. between 1 picosecond and 1 nanosecond) provides a view of their biological function, but this has been challenging in the deep-UV spectrum (wavelengths below 300 nm) where most biologically relevant molecules such as amino acids, DNA and peptide helices absorb light.

The limitations are due to the lack of adequate sources of pulsed light and of sensitive detection schemes. But now, the group of Majed Chergui at the Lausanne Centre for Ultrafast Science (EPFL) has developed a setup that allows the visualization of the chiral response of (bio)molecules by CD spectroscopy with a resolution of 0.5 picoseconds.

The setup uses a photoelastic modulator, which is an optical device that can control the polarization of light. In this system, the modulator permits shot-to-shot polarization switching of a 20 kHz femtosecond pulse train in the deep-UV range (250-370 nm). It is then possible to record changes in the chirality of molecules at variable time-delays after they are excited with a short laser pulse.

"Amino acid residues and DNA bases absorb light below 300 nm," says Malte Oppermann, the paper's first author. "This set-up is the first to cover this region, and we successfully tested it on a model molecular system. Our next aim is to move on to larger biosystems, like DNA oligomers."

###

Other contributors

University of Geneva
University of Zurich

Reference

Malte Oppermann, Benjamin Bauer, Thomas Rossi, Francesco Zinna, Jan Helbing, Jérôme Lacour, Majed Chergui. Ultrafast broadband circular dichroism in the deep ultraviolet. Optica 6(1): 56-60, 10 January 2019. DOI: 10.1364/OPTICA.6.000056

Media Contact

Nik Papageorgiou
n.papageorgiou@epfl.ch
41-216-932-105

 @EPFL_en

http://www.epfl.ch/index.en.html 

Nik Papageorgiou | EurekAlert!
Further information:
https://actu.epfl.ch/news/chirality-in-real-time
http://dx.doi.org/10.1364/OPTICA.6.000056

More articles from Life Sciences:

nachricht The hidden structure of the periodic system
17.06.2019 | Max-Planck-Institut für Mathematik in den Naturwissenschaften (MPIMIS)

nachricht Tiny probe that senses deep in the lung set to shed light on disease
17.06.2019 | University of Edinburgh

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The hidden structure of the periodic system

The well-known representation of chemical elements is just one example of how objects can be arranged and classified

The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to...

Im Focus: MPSD team discovers light-induced ferroelectricity in strontium titanate

Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.

Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...

Im Focus: Determining the Earth’s gravity field more accurately than ever before

Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.

The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...

Im Focus: Tube anemone has the largest animal mitochondrial genome ever sequenced

Discovery by Brazilian and US researchers could change the classification of two species, which appear more akin to jellyfish than was thought.

The tube anemone Isarachnanthus nocturnus is only 15 cm long but has the largest mitochondrial genome of any animal sequenced to date, with 80,923 base pairs....

Im Focus: Tiny light box opens new doors into the nanoworld

Researchers at Chalmers University of Technology, Sweden, have discovered a completely new way of capturing, amplifying and linking light to matter at the nanolevel. Using a tiny box, built from stacked atomically thin material, they have succeeded in creating a type of feedback loop in which light and matter become one. The discovery, which was recently published in Nature Nanotechnology, opens up new possibilities in the world of nanophotonics.

Photonics is concerned with various means of using light. Fibre-optic communication is an example of photonics, as is the technology behind photodetectors and...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

Novel communications architecture for future ultra-high speed wireless networks

17.06.2019 | Information Technology

Climate Change in West Africa

17.06.2019 | Earth Sciences

Robotic fish to replace animal testing

17.06.2019 | Ecology, The Environment and Conservation

VideoLinks
Science & Research
Overview of more VideoLinks >>>