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Department of Physics

Biophysics Research Group

Biophysics is a rapidly growing subdiscipline of Physics in numerous well-developed countries and holds tremendous promise for the advancement of science and innovation in the 21st century. Despite this, there is only little activity in South Africa.

We are exploring energetic and structural dynamics of biological processes at the molecular level, mainly from an experimental point of view, backed by theoretical modelling. There are numerous research projects available, which can be divided into two major research thrusts:

  1. Ultrafast spectroscopy and laser coherent control of excitation energy transfer in natural and artificial light-harvesting complexes. State-of-the-art laser spectroscopy techniques are used to resolve and control processes on timescales down to femtoseconds. The research has a strong application in the development of next-generation bio-inspired solar cells and the investigation of crop failure under drought stress or conditions of high solar irradiation.

  2. Development of new experimental approaches to probe the molecular dynamics of single biological molecules in real time in environments that mimic the natural environments to an increasingly better extent. The ultimate goal is to develop in vivo nano-spectroscopy. The techniques are currently applied on natural light-harvesting complexes and will eventually involve various bio-medical applications. The approach is from two directions:
a) Investigating the spectroscopic properties of freely diffusing macromolecules by combining single particle tracking with other conventional single molecule spectroscopy techniques.

b) Developing novel sub-diffraction-limited spectroscopy techniques.

The research is conducted in collaboration with various prestigious national and international groups and participation will offer the opportunity to visit some of these groups.

Current Biophysics group (as of August 2014)

CV of Dr. Krüger


Collaborations

International collaboration

  • Vrije Universiteit Amsterdam: Rienk van Grondelle, Roberta Croce
  • University of Freiburg, Germany: Andreas Buchleitner
  • Vilnius University, Lithuania: Leonas Valkunas
  • Queen Mary University of London: Alexander Ruban
  • Charles University, Prague: Tomas Mancal

National collaboration

  • National Laser Center (NLC), CSIR, South Africa
  • Centre for Quantum Technology, UKZN, South Africa
  • Molecular and Cell Biology, UCT, South Africa

Motivations for pursuing research in Biophysics:

  • It is a strongly emerging and very promising scientific discipline.
  • It involves solving interesting, fundamental questions in physics and biology.
  • Processes involved with the essence of life are explored.
  • Innovation is a strong component, which means that you can make an impact in society while at the same time doing fundamental science.
  • A biological background is not necessary when approaching the field from a Physics point of view.

If you are new to the world of Biophysics, the following links are recommended.

Research Projects

Below is a list of specific research projects:

  • Laser coherent control of natural and artificial light-harvesting complexes. The primary goal is to develop strategies for controlling excitation energy transfer.
  • Examining molecular mechanisms of photoprotection in desiccation tolerant plants.
  • Developing photoluminescence-excitation spectroscopy to investigate molecular mechanisms of photoprotection in single complexes and small ensembles of the main plant light-harvesting complex and plant Photosystem II supercomplexes.
  • Investigating single-molecule properties of light-harvesting complexes in environments that strongly reflect their natural environment. The first major application will be on a better understanding of molecular mechanisms of photoprotection.
  • Investigating structure-function relationships of solubilised light-harvesting complexes by combining single-particle tracking with other conventional single-molecule techniques.
  • Developing optical nanoantennas, a strongly emerging technology with a promising application in nano-spectroscopy.

Interests and Experiences

  • A strong background in Physics or Physical Chemistry is strongly beneficial. Applicants with a different background may also be considered, but this needs to be strongly motivated.
  • Some experience with lasers and/or chemistry is favourable but not obligatory.
  • Computer programming is a requirement for most of the projects.
  • Apart from the experimental approach involving spectroscopy,the underlying physics of most projects strongly overlaps with condensed matter physics and semiconductor physics. Some experience in these fields is therefore favourable but not obligatory.
  • Candidates are to have an inquisitive and eager spirit to discover exciting physics.

 
Contact person: Dr TPJ Krüger