Channels

 

Special Offers & Promotions

 

 

Latest News

 

 

View Channel

New Products

 

 

View Channel

Video Presentations

 

 

View Channel

Separation Science

 

 

View Channel

Microscopy & Image Analysis

 

 

View Channel

Laboratory Automation & IT Solutions

 

 

View Channel

 

JPK reports on how graphenes are being studied using AFM to better characterize their properties at the Humboldt University in Berlin

graphenesJPK Instruments, a world-leading manufacturer of nanoanalytic instrumentation for research in life sciences and soft matter, reports on a keynote paper in Nano Letters where Dr Nikolai Severin and his co-workers from the group of Professor Jürgen P. Rabe have applied JPK's NanoWizard®II Ultra system to improve their understanding of the properties of graphene.

The Physics of Macromolecules group of Professor Jürgen P. Rabe has a central research goal to correlate structure and dynamics of molecular systems at interfaces with mechanical, electronic, optical and (bio-)chemical properties from molecular to macroscopic length and time scales. Manipulation and imaging of single molecules and supramolecular systems with a scanning force microscope (SFM) is of paramount importance to the understanding of structure formation and the measurement of mechanical properties. The group is also involved in understanding and developing molecular electronics and organic electronic properties.

Within this group is Dr Nikolai Severin, recently the lead author of a paper in Nano Letters* which shows the use of AFM in the study of graphenes. The electronic properties of graphenes depend sensitively on their deformation, and therefore strain-engineered graphene electronics is envisioned. In order to deform graphenes locally, the group has mechanically exfoliated single and few layer graphenes onto atomically flat mica surfaces covered with isolated double stranded plasmid DNA rings. Using scanning force microscopy in both contact and intermittent contact modes, they have found that the graphenes replicate the topography of the underlying DNA with high precision. The availability of macromolecules of different topologies, e.g., programmable DNA patterns render this approach promising for new graphene based device designs. Furthermore, the encapsulation of single macromolecules offers new prospects for analytical scanning probe microscopy techniques.

Dr Severin has seen that graphene provides enhanced protection of DNA molecules to shear forces exerted during scanning force microscopy in contact mode. In addition, graphene will act as a surface protective layer against the ambient, e.g., against oxidation, since it is impermeable to gases. Taking into account both the high electric conductivity of graphene and its extremely small thickness, this offers new opportunities for scanning probe microscopies and spectroscopies, such as scanning tunneling or tip enhanced Raman spectroscopy for analyses of both locally deformed graphene and confined molecules. Summarising, Dr Severin said, "We have successfully demonstrated that topography of graphenes can be controlled with the precision down to single molecules, i.e. graphenes are so flexible that they can replicate the topography of single molecules, when deposited on these molecules."

He also commented on some of the reasons for choosing to work with JPK NanoWizard® II for this work: "We are able to use a relatively large size of samples and scan areas of up to 30 microns. The linearized scanner is most important for us to precisely measure the height of DNA and their cross sections. The system shows little thermal drift which is important when making measurements on such small length scales. I also found the software was quite easy to use."

For more details about JPK's specialist products and applications for the bio and nano sciences, please contact JPK on +49 30533112070, visit the web site: http://www.jpk.com/ or see more on Facebook: www.jpk.com/facebook

* Reference acknowledgment:
Replication of Single Macromolecules with Graphene, N . Severin*†, M. Dorn†, A. Kalachev‡, and J. P. Rabe*†;†Department of Physics, Humboldt-Universitaat zu Berlin, Newtonstrasse 15, 12489 Berlin, Germany. ‡ PlasmaChem GmbH, Rudower Chaussee 29, 12489 Berlin, Germany: Nano Lett., 2011, 11 (6), pp 2436-2439; DOI: 10.1021/nl200846f; Publication Date (Web): May 16, 2011; Copyright © 2011 American Chemical Society


If you have not logged into the website then please enter your details below.



 

Subscribe to any of our newsletters for the latest on new laboratory products, industry news, case studies and much more!

Newsletters from Lab Bulletin

 

Request your free copies HERE

 

 

 

Popular this Month

Top 10 most popular articles this month

 

 

Today's Picks

 


 

Looking for a Supplier?

Search by company or by product

 


Company Name:

Product:


 

 

 

 

Please note Lab Bulletin does not sell, supply any of the products featured on this website. If you have an enquiry, please use the contact form below the article or company profile and we will send your request to the supplier so that they can contact you directly.

Lab Bulletin is published by newleaf marketing communications ltd.


 

Media Partners

 

Exhibitions & Events