Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > 3D Dynamic Imaging of Soft Materials: Berkeley Lab Researchers Apply Transmission Electron Microscopy Through Unique Graphene Liquid Cell

This schematic of a graphene liquid cell shows multiple liquid pockets containing single nanoparticles, dimers composed of dsDNA bridges in different lengths, and trimers.
This schematic of a graphene liquid cell shows multiple liquid pockets containing single nanoparticles, dimers composed of dsDNA bridges in different lengths, and trimers.

Abstract:
Autumn is usually not such a great time for big special effects movies as the summer blockbusters have faded and those for the holiday season have not yet opened. Fall is more often the time for thoughtful films about small subjects, which makes it perfect for the unveiling of a new movie produced by researchers at the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab). Through a combination of transmission electron microscopy (TEM) and their own unique graphene liquid cell, the researchers have recorded the three-dimensional motion of DNA connected to gold nanocrystals. This is the first time TEM has been used for 3D dynamic imaging of so-called soft materials.



This TEM movie (left) and 3D reconstruction (right) shows the motion of a gold nanoparticle trimer (yellow spheres) connected by DNA (green). The red arrow highlights rotational motion and dark circular shapes following this trimer are calculated projections that match what is shown in the TEM movie.

3D Dynamic Imaging of Soft Materials: Berkeley Lab Researchers Apply Transmission Electron Microscopy Through Unique Graphene Liquid Cell

Berkeley, CA | Posted on October 3rd, 2013

"Our demonstration of 3D dynamic imaging goes beyond TEM's conventional use in seeing flat, dry samples and opens many exciting opportunities for studying the dynamics of biological macromolecular assemblies and artificial nanostructures," says physicist Alex Zettl, one of the leaders of this research. "These results were made possible by our novel graphene liquid cell, which can meet the challenges of using TEM to image soft materials."

Zettl, who holds joint appointments with Berkeley Lab's Materials Sciences Division and UC Berkeley's Physics Department where he directs the Center of Integrated Nanomechanical Systems, is one of the co-authors of a paper in NANO Letters describing this research. The paper is titled "3D Motion of DNA-Au Nanoconjugates in Graphene Liquid Cell Electron Microscopy."

Paul Alivisatos, Berkeley Lab Director and UC Berkeley's Samsung Distinguished Chair in Nanoscience and Nanotechnology, is the corresponding author. Other authors are Qian Chen, Jessica Smith, Jungwon Park, Kwanpyo Kim, Davy Ho and Haider Rasool.

The term "soft materials" takes in a vast variety of stuff, including DNA, proteins and other biological compounds, plastics, therapeutic drugs, flexible electronics, and certain types of photovoltaics. Despite their ubiquitous presence in our daily lives, soft materials pose many questions because the study of their dynamics at the nanoscale, especially biological systems, has been a challenge. TEM, in which a beam of electrons rather than light is used for illumination and magnification, provides the resolution for such studies but can only be used in a high vacuum as molecules in the air disrupt the electron beam. Since liquids evaporate in high vacuum, samples of soft materials, which have been described as "highly viscous fluids," must be hermetically sealed in special solid containers (called cells) with a viewing window before being imaged with TEM.

In the past, liquid cells featured silicon-based viewing windows whose thickness limited resolution and perturbed the natural state of the soft materials. Zettl and Alivisatos and their respective research groups overcame these limitations with the development of a liquid cell based on a graphene membrane only a single atom thick. This development was done in close cooperation with researchers at the National Center for Electron Microscopy (NCEM), which is located at Berkeley Lab.

"Our graphene liquid cells pushed the spatial resolution of liquid phase TEM imaging to the atomic scale but still focused on growth trajectories of metallic nanocrystals," says lead author Qian Chen, a postdoctoral fellow in Alivisatos's research group. "Now we've adopted the technique to imaging the 3D dynamics of soft materials, starting with double-strand (dsDNA) connected to gold nanocrystals and achieved nanometer resolution."

To create the cell, two opposing graphene sheets are bonded to one another by their van der Waals attraction. This forms a sealed nanoscale chamber and creates within the chamber a stable aqueous solution pocket approximately 100 nanometers in height and one micron in diameter. The single atom thick graphene membrane of the cells is essentially transparent to the TEM electron beam, minimizing the unwanted loss of imaging electrons and providing superior contrast and resolution compared to silicon-based windows. The aqueous pockets allow for up to two minutes of continuous imaging of soft material samples exposed to a 200 kilo Volt imaging electron beam. During this time, soft material samples can freely rotate.

After demonstrating that their graphene liquid cell can seal an aqueous sample solution against a TEM high vacuum, the Berkeley researchers used it to study the types of gold-dsDNA nanoconjugates that have been widely used as dynamic plasmonic probes.

"The presence of double-stranded DNA molecules incorporates the major challenges of studying the dynamics of biological samples with liquid phase TEM," says Alivisatos. "The high-contrast gold nanocrystals facilitate tracking of our specimens."

The Alivisatos and Zettl groups were able to observe dimers, pairs of gold nanoparticles, tethered by a single piece of dsDNA, and trimers, three gold nanoparticles, connected into a linear configuration by two single pieces of dsDNA. From a series of 2D projected TEM images captured while the samples were rotating, the researchers were to reconstruct 3D configuration and motions of the samples as they evolved over time.

"This information would be inaccessible with conventional TEM techniques," Chen says.

This research was supported in part by the Defense Threat Reduction Agency and by the National Science Foundation. The development of the liquid cell technique for in situ TEM, originally reported in the journal Science in 2012, was supported by the DOE Office of Science.

####

About Berkeley Lab
Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

For more information, please click here

Contacts:
Lynn Yarris

510-486-5375

Copyright © Berkeley Lab

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

For more about the research of Alex Zettl and his group go here:

For more about the research of Paul Alivisatos and his group go here:

For more about the National Center for Electron Microscopy go here:

Related News Press

Videos/Movies

Like a hall of mirrors, nanostructures trap photons inside ultrathin solar cells April 22nd, 2014

Graphene

Nanomaterial Outsmarts Ions April 22nd, 2014

Imaging

Berkeley Lab Researchers Demonstrate First Size-based Chromatography Technique for the Study of Living Cells April 22nd, 2014

News and information

Berkeley Lab Researchers Demonstrate First Size-based Chromatography Technique for the Study of Living Cells April 22nd, 2014

PETA science consortium to present hazard testing strategy at nanotoxicology meeting: High tech field ripe for use of sophisticated non-animal testing strategies April 22nd, 2014

Harris & Harris Group Notes the Receipt of Proceeds From the Sale of Molecular Imprints' Semiconductor Business to Canon April 22nd, 2014

National Space Society Congratulates SpaceX on the Success of CRS-3 and the First Flight of the Falcon 9R April 22nd, 2014

Laboratories

Berkeley Lab Researchers Demonstrate First Size-based Chromatography Technique for the Study of Living Cells April 22nd, 2014

Govt.-Legislation/Regulation/Funding/Policy

Cloaked DNA nanodevices survive pilot mission: Successful foray opens door to virus-like DNA nanodevices that could diagnose diseased tissues and manufacture drugs to treat them April 22nd, 2014

Berkeley Lab Researchers Demonstrate First Size-based Chromatography Technique for the Study of Living Cells April 22nd, 2014

Progress made in developing nanoscale electronics: New research directs charges through single molecules April 21st, 2014

'Exotic' material is like a switch when super thin April 18th, 2014

Discoveries

Like a hall of mirrors, nanostructures trap photons inside ultrathin solar cells April 22nd, 2014

Nanomaterial Outsmarts Ions April 22nd, 2014

Vacuum Ultraviolet Lamp of the Future Created in Japan: First Solid-State Vacuum UV Phosphor, Described in APL-Materials, Promises Smaller, Safer, Longer Lasting, Low Power Lamps for Industrial Applications April 22nd, 2014

Berkeley Lab Researchers Demonstrate First Size-based Chromatography Technique for the Study of Living Cells April 22nd, 2014

Announcements

Berkeley Lab Researchers Demonstrate First Size-based Chromatography Technique for the Study of Living Cells April 22nd, 2014

PETA science consortium to present hazard testing strategy at nanotoxicology meeting: High tech field ripe for use of sophisticated non-animal testing strategies April 22nd, 2014

Harris & Harris Group Notes the Receipt of Proceeds From the Sale of Molecular Imprints' Semiconductor Business to Canon April 22nd, 2014

National Space Society Congratulates SpaceX on the Success of CRS-3 and the First Flight of the Falcon 9R April 22nd, 2014

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals

Nanomaterial Outsmarts Ions April 22nd, 2014

Vacuum Ultraviolet Lamp of the Future Created in Japan: First Solid-State Vacuum UV Phosphor, Described in APL-Materials, Promises Smaller, Safer, Longer Lasting, Low Power Lamps for Industrial Applications April 22nd, 2014

Berkeley Lab Researchers Demonstrate First Size-based Chromatography Technique for the Study of Living Cells April 22nd, 2014

Nanoreporters tell 'sour' oil from 'sweet': Rice University's hydrogen sulfide nanoreporters gather intel on oil before pumping April 22nd, 2014

Tools

MRI, on a molecular scale: Researchers develop system that could one day peer into the atomic structure of individual molecules April 20th, 2014

Oxford Instruments Asylum Research Introduces the MFP-3D InfinityTM AFM Featuring Powerful New Capabilities and Stunning High Performance April 18th, 2014

More effective kidney stone treatment, from the macroscopic to the nanoscale April 17th, 2014

Aerotech X-Y ball-screw stage for economical high performance Planar positioning April 16th, 2014

Military

Cloaked DNA nanodevices survive pilot mission: Successful foray opens door to virus-like DNA nanodevices that could diagnose diseased tissues and manufacture drugs to treat them April 22nd, 2014

'Exotic' material is like a switch when super thin April 18th, 2014

Tiny particles could help verify goods: Chemical engineers hope smartphone-readable microparticles could crack down on counterfeiting April 15th, 2014

Targeting cancer with a triple threat: MIT chemists design nanoparticles that can deliver three cancer drugs at a time April 15th, 2014

NanoNews-Digest
The latest news from around the world, FREE







  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE