Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nanoscaled Tip Writes Artificial Cell Membranes

15.10.2013
Biomimetic Membranes on Graphene Open up Novel Applications in Biotechnology – Publication in “Nature Communications“

Researchers around Dr. Michael Hirtz from Karlsruhe Institute of Technology and Dr. Aravind Vijayaraghavan from the University of Manchester have developed a new method to produce artificial membranes:


By means of lipid dip-pen nanolithography (L-DPN), lipid membranes are written directly onto the two-dimensional carbon graphene. (Graphics: Hirtz/Nature Communications)

Using a nanoscaled tip, they write tailored patches of phospholipid membrane onto a graphene substrate. The resulting biomimetic membranes, i.e. membranes simulating biological structures, allow for the specific investigation of functions of cell membranes and the development of novel applications in medicine and biotechnology, such as biosensors. The method is now presented online in “Nature Communications”.

Lipids (from Greek lipos, “fat”) are central structural elements of cell membranes. The human body contains about 100 trillion cells, each of which is enveloped in a cell membrane which essentially is a double layer of partly hydrophilic, partly hydrophobic phosphorus-containing lipids. These cell membranes contain numerous proteins, ion channels, and other biomolecules, each performing vital functions. It is therefore important to study cell membranes for many areas of medicine and biotechnology. Better understanding of their functions will open up novel applications, such as sensors with biological components, use of enzymes as catalysts, or specific introduction of medical substances. However, it is very difficult to study the membranes directly in live cells inside the human body.

Consequently, researchers frequently use model membranes that are applied to special surfaces. These biomimetic systems, i.e. systems simulating biological structures, are more convenient and can be controlled much better. An international group of researchers around Dr. Michael Hirtz, head of the project in the research unit of Professor Harald Fuchs at the KIT Institute of Nanotechnology (INT), and Dr. Aravind Vijayaraghavan from the University of Manchester, Great Britain, now presents a new method to produce biomimetic membranes: They write tailored patches of phospholipid membrane onto a graphene substrate by means of lipid dip-pen nanolithography (L-DPN), a method developed at KIT.

“The L-DPN technique uses a very sharp tip to write lipid membranes onto surfaces in a way similar to what a quill pen does with ink on paper,” explains Dr. Michael Hirtz from the INT. This tip has an apex in the range of a few nanometers only and is controlled with a high precision by a machine. In this way, minute structures can be produced, smaller than cells and even down to the nanoscale (1 nanometer corresponds to 10-9 meters). By employing parallel arrays of these tips, different mixtures of lipids can be written in parallel, allowing for patterns of variable chemical composition with a size smaller than that of an individual cell.

The graphene that is used as a substrate is a semi-metal with unique electronic properties. According to Dr. Aravin Vijayaraghavan from the University of Manchester, the lipids applied onto graphene spread uniformly, thus forming high-quality membranes. Other advantages of graphene are its tunable conductivity and its property to quench fluorescence of labeled phospholipids. When the lipids contain the corresponding binding sites, such as biotin, the membranes actively bind streptavidin, a protein produced by certain bacteria and used in various biotechnological methods. When the lipids are charged, charge is transferred from the lipids into graphene. This changes the conductivity of graphene, which may be used as a detection signal in biosensors.

The researchers around Hirtz will use their biomimetic membranes in the future to construct novel biosensors based on graphene and lipids. It is planned to design sensors that react to the binding of proteins by a change of conductivity as well as sensors detecting the function of ion channels in membranes. Ion channels are pore-forming proteins via which electrically charged particles can cross the membrane. “Protein sensors might be applied in medical diagnostics. Controlling the function of ion channels is important in drug research,” the KIT scientist says.

M. Hirtz, A. Oikonomou, T. Georgiou, H. Fuchs, & A. Vijayaraghavan: Multiplexed biomimetic lipid membranes on graphene by dip-pen nanolithography. Nature Communications,
10 Oct 2013 | DOI: 10.1038/ncomms3591.

Karlsruhe Institute of Technology (KIT) is a public corporation according to the legislation of the state of Baden-Württemberg. It fulfills the mission of a university and the mission of a national research center of the Helmholtz Association. Research activities focus on energy, the natural and built environment as well as on society and technology and cover the whole range extending from fundamental aspects to application. With about 9000 employees, including nearly 6000 staff members in the science and education sector, and 24000 students, KIT is one of the biggest research and education institutions in Europe. Work of KIT is based on the knowledge triangle of research, teaching, and innovation.

or, 10.10.2013

For further information, please contact:

Margarete Lehné
Presse, Kommunikation und Marketing
Phone: +49 721 608-48121
Fax: +49 721 608-45681
margarete lehne∂kit edu

Monika Landgraf | EurekAlert!
Further information:
http://www.kit.edu

More articles from Life Sciences:

nachricht Colorectal cancer risk factors decrypted
13.07.2018 | Max-Planck-Institut für Stoffwechselforschung

nachricht Algae Have Land Genes
13.07.2018 | Julius-Maximilians-Universität Würzburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

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...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

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...

Im Focus: Breaking the bond: To take part or not?

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...

Im Focus: New 2D Spectroscopy Methods

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....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Research finds new molecular structures in boron-based nanoclusters

13.07.2018 | Materials Sciences

Algae Have Land Genes

13.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>