Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button

Home > Press > 'Super-resolution' microscope possible for nanostructures

A new type of super-resolution optical microscopy takes a high-resolution image (at right) of graphite "nanoplatelets" about 100 nanometers wide. The imaging system, called saturated transient absorption microscopy, or STAM, uses a trio of laser beams and represents a practical tool for biomedical and nanotechnology research.Weldon School of Biomedical Engineering, Purdue University
A new type of super-resolution optical microscopy takes a high-resolution image (at right) of graphite "nanoplatelets" about 100 nanometers wide. The imaging system, called saturated transient absorption microscopy, or STAM, uses a trio of laser beams and represents a practical tool for biomedical and nanotechnology research.

Weldon School of Biomedical Engineering, Purdue University

Abstract:
Far-Field Imaging of Non-Fluorescent Species with Sub-Diffraction Resolution

Pu Wang1, #, Mikhail N. Slipchenko1, #, James Mitchell2, Chen Yang3, Eric O. Potma4, Xianfan Xu2, Ji-Xin Cheng13, *4

1 Weldon School of Biomedical Engineering, Purdue University

2 School of Mechanical Engineering and Birck Nanotechnology Center, Purdue University

3 Department of Chemistry, Purdue University

4 Department of Chemistry, University of California, Irvine

Super-resolution optical microscopy is opening a new window to unveil the unseen details on the nanoscopic scale. Current far-field super-resolution techniques rely on fluorescence as the read-out. Here, we demonstrate a scheme for breaking the diffraction limit in far-field imaging of non-fluorescent species by using spatially controlled saturation of electronic absorption. Our method is based on a pump-probe process where a modulated pump field perturbs the charge-carrier density in a sample, thus modulating the transmission of a probe field. A doughnut shape laser beam is then added to transiently saturate the electronic transition in the periphery of the focal volume, thus the induced modulation in the sequential probe pulse only occurs at the focal center. By raster scanning the three collinearly aligned beams, high-speed sub-diffraction-limited imaging of graphite nano-platelets was performed. This technique potentially enables super-resolution imaging of nano-materials and non-fluorescent chromophores, which may remain out of reach for fluorescence-based methods.

'Super-resolution' microscope possible for nanostructures

West Lafayette, IN | Posted on April 29th, 2013

Researchers have found a way to see synthetic nanostructures and molecules using a new type of super-resolution optical microscopy that does not require fluorescent dyes, representing a practical tool for biomedical and nanotechnology research.

"Super-resolution optical microscopy has opened a new window into the nanoscopic world," said Ji-Xin Cheng, an associate professor of biomedical engineering and chemistry at Purdue University.

Conventional optical microscopes can resolve objects no smaller than about 300 nanometers, or billionths of a meter, a restriction known as the "diffraction limit," which is defined as half the width of the wavelength of light being used to view the specimen. However, researchers want to view molecules such as proteins and lipids, as well as synthetic nanostructures like nanotubes, which are a few nanometers in diameter.

Such a capability could bring advances in a diverse range of disciplines, from medicine to nanoelectronics, Cheng said.

"The diffraction limit represents the fundamental limit of optical imaging resolution," Cheng said. "Stefan Hell at the Max Planck Institute and others have developed super-resolution imaging methods that require fluorescent labels. Here, we demonstrate a new scheme for breaking the diffraction limit in optical imaging of non-fluorescent species. Because it is label-free, the signal is directly from the object so that we can learn more about the nanostructure."

Findings are detailed in a research paper that appeared online Sunday (April 28) in the journal Nature Photonics.

The imaging system, called saturated transient absorption microscopy, or STAM, uses a trio of laser beams, including a doughnut-shaped laser beam that selectively illuminates some molecules but not others. Electrons in the atoms of illuminated molecules are kicked temporarily into a higher energy level and are said to be excited, while the others remain in their "ground state." Images are generated using a laser called a probe to compare the contrast between the excited and ground-state molecules.

The researchers demonstrated the technique, taking images of graphite "nanoplatelets" about 100 nanometers wide.

"It's a proof of concept and has great potential for the study of nanomaterials, both natural and synthetic," Cheng said.

The doughnut-shaped laser excitation technique, invented by researcher Stefan Hell, makes it possible to focus on yet smaller objects. Researchers hope to improve the imaging system to see objects about 10 nanometers in diameter, or about 30 times smaller than possible using conventional optical microscopes.

"We are not there yet, but a few schemes can be applied to further increase the resolution of our system," Cheng said.

The paper was co-authored by biomedical engineering doctoral student Pu Wang; research scientist Mikhail N. Slipchenko; mechanical engineering doctoral student James Mitchell; Chen Yang, an assistant professor of physical chemistry at Purdue; Eric O. Potma, an associate professor of chemistry at the University of California, Irvine; Xianfan Xu, Purdue's James J. and Carol L. Shuttleworth Professor of Mechanical Engineering; and Cheng.

Future research may include work to use lasers with shorter wavelengths of light. Because the wavelengths are shorter, the doughnut hole is smaller, possibly allowing researchers to focus on smaller objects.

The work will be discussed during the third annual Spectroscopic Imaging: A New Window into the Unseen World workshop on May 23 and 24 at Purdue. The workshop is hosted by the university's Weldon School of Biomedical Engineering. More workshop information is available at www.conf.purdue.edu/cheng

The research is funded by the National Institutes of Health, National Science Foundation and the Defense Advanced Research Projects Agency.

Note to Journalists: Ji-Xin Cheng's name is pronounced "Gee-Shin." Journalists may obtain a copy of the research paper by contacting Nature at or calling 212-726-9231.

####

For more information, please click here

Contacts:
Writer:
Emil Venere
765-494-4709


Sources:
Ji-Xin Cheng
765-494-4335


Chen Yang
765-496-3346

Copyright © Purdue University

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

Department of Chemistry:

Related News Press

News and information

Scientists change properties of zeolites to improve hemodialysis July 29th, 2016

Novel state of matter: Observation of a quantum spin liquid July 29th, 2016

A new type of quantum bits July 29th, 2016

Lonely atoms, happily reunited July 29th, 2016

Beating the heat a challenge at the nanoscale: Rice University scientists detect thermal boundary that hinders ultracold experiments July 28th, 2016

Imaging

Lonely atoms, happily reunited July 29th, 2016

Pixel-array quantum cascade detector paves the way for portable thermal imaging devices: Research team from TU-Wien Center for Micro- and Nanostructures have developed a new 'cooler' sensing instrument thereby increasing energy-efficiency and enhancing mobility for diagnostic tes July 28th, 2016

WSU researchers 'watch' crystal structure change in real time: Breakthrough made possible by new Argonne facility July 27th, 2016

Govt.-Legislation/Regulation/Funding/Policy

A new type of quantum bits July 29th, 2016

Thomas Swan and NGI announce unique partnership July 28th, 2016

Penn team uses nanoparticles to break up plaque and prevent cavities July 28th, 2016

Beating the heat a challenge at the nanoscale: Rice University scientists detect thermal boundary that hinders ultracold experiments July 28th, 2016

Discoveries

Scientists change properties of zeolites to improve hemodialysis July 29th, 2016

Novel state of matter: Observation of a quantum spin liquid July 29th, 2016

A new type of quantum bits July 29th, 2016

Lonely atoms, happily reunited July 29th, 2016

Announcements

Scientists change properties of zeolites to improve hemodialysis July 29th, 2016

Novel state of matter: Observation of a quantum spin liquid July 29th, 2016

A new type of quantum bits July 29th, 2016

Lonely atoms, happily reunited July 29th, 2016

Tools

Lonely atoms, happily reunited July 29th, 2016

Pixel-array quantum cascade detector paves the way for portable thermal imaging devices: Research team from TU-Wien Center for Micro- and Nanostructures have developed a new 'cooler' sensing instrument thereby increasing energy-efficiency and enhancing mobility for diagnostic tes July 28th, 2016

WSU researchers 'watch' crystal structure change in real time: Breakthrough made possible by new Argonne facility July 27th, 2016

Enhancing molecular imaging with light: New technology platform increases spectroscopic resolution by 4 fold July 27th, 2016

Military

Beating the heat a challenge at the nanoscale: Rice University scientists detect thermal boundary that hinders ultracold experiments July 28th, 2016

Ultrasensitive sensor using N-doped graphene July 26th, 2016

Borrowing from pastry chefs, engineers create nanolayered composites: Method to stack hundreds of nanoscale layers could open new vistas in materials science July 25th, 2016

Integration of novel materials with silicon chips makes new 'smart' devices possible July 25th, 2016

Photonics/Optics/Lasers

Beating the heat a challenge at the nanoscale: Rice University scientists detect thermal boundary that hinders ultracold experiments July 28th, 2016

Attosecond physics: Mapping electromagnetic waveforms July 25th, 2016

RMIT researchers make leap in measuring quantum states July 21st, 2016

The birth of quantum holography: Making holograms of single light particles! July 21st, 2016

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







Car Brands
Buy website traffic