A plant or an animal cell uses numerous processes to sort and assemble tiny building blocks into larger molecules, to rebuild molecules or to dissolve them. Using synthetic gel particles, scientists try to simulate these cellular procedures; however, mimicking the complexity of natural processes presents a formidable task for scientists.
Researchers from the DWI – Leibniz Institute for Interactive Materials in Aachen and the University of Freiburg now developed a set of four different, micrometer-sized building blocks, which can self-sort and co-assemble into defined compositions and disassemble at the push of a button.
A set of blue, red, green and yellow Lego bricks helps to visualize this research approach. It is very simple to build a multicolored object from these bricks, without considering the colors of the single bricks. To make it slightly more complicated, one could initially sort the bricks by their color and then build objects that are either blue, red, green or yellow.
Such processes are referred to as ‘unsocial assemblies’ if they are driven by themselves. To make things even more complex, you could also build some objects from red and blue bricks and others from green and yellow bricks. These processes, if running simultaneously, are termed ‘social assemblies’.
The scientists from Aachen and Freiburg solved a similar task; however on a microscopic scale by using small gel particles instead of Lego bricks. These so-called microgels are water-rich, sponge-like gel particles, which can be chemically modified.
“We used four different types of microgels for our experiments. The microgels can self-assemble in an ‘unsocial’ manner, staying amongst themselves, or co-assemble in a ‘social’ manner, with a second type of microgel,” explains Dr. Alexander Kühne from DWI. He coordinated this project together with Prof. Dr. Andreas Walther, a former DWI scientist who recently moved to the University of Freiburg.
The challenge of this project was to enable the microgels to distinguish between right and wrong partners. To achieve this, the scientists integrated molecular interactions so that only specific types of microgels would interact with each other – just like a key, which can only open a very specific lock.
However, instead of keys and locks, the researchers applied switchable molecules that integrate into cyclic sugar moieties. Triggered by certain chemical conditions or by light the researchers could control the molecular shape and their interactions during the experiment. This way, the microgels can self-sort, self-assemble and disassemble at the push of a button.
“We use these types of experiments to get a better understanding of processes running in natural cells,” says Alexander Kühne. “In addition, progress in this field of research will eventually help us to develop biologically inspired, interactive materials.”
Publication: Kang Han, Dennis Go, Thomas Tigges, Khosrow Rahimi, Alexander J. C. Kuehne, Andreas Walther, “Social Self-Sorting of Colloidal Families in Co-Assembling Microgel Systems”, Angewandte Chemie International Edition 2017, DOI: 10.1002/anie.201612196.
Dr. Janine Hillmer | idw - Informationsdienst Wissenschaft
Pollen taxi for bacteria
18.07.2018 | Technische Universität München
Biological signalling processes in intelligent materials
18.07.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
18.07.2018 | Life Sciences
18.07.2018 | Life Sciences
18.07.2018 | Information Technology