Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

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

Conductive Inks: booming to $2.8 billion by 2024 April 17th, 2014

High-temperature plasmonics eyed for solar, computer innovation April 17th, 2014

INSCX™ exchange to present Exchange trade reporting mechanism for engineered nanomaterials (NMs) to UK regulation agencies, insurers and upstream/downstream users April 17th, 2014

Transparent Conductive Films and Sensors Are Hot Segments in Printed Electronics: Start-ups in these fields show above-average momentum, while companies working on emissive displays such as OLED are fading, Lux Research says April 17th, 2014

Imaging

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

Govt.-Legislation/Regulation/Funding/Policy

Novel stapled peptide nanoparticle combination prevents RSV infection, study finds April 17th, 2014

INSCX™ exchange to present Exchange trade reporting mechanism for engineered nanomaterials (NMs) to UK regulation agencies, insurers and upstream/downstream users April 17th, 2014

Scientists Capture Ultrafast Snapshots of Light-Driven Superconductivity: X-rays reveal how rapidly vanishing 'charge stripes' may be behind laser-induced high-temperature superconductivity April 16th, 2014

'Life Redesigned: The Emergence of Synthetic Biology' Lecture at Brookhaven Lab on Wednesday, April 30: Biomedical Engineer James Collins to Speak for BSA Distinguished Lecture Series April 16th, 2014

Discoveries

Novel stapled peptide nanoparticle combination prevents RSV infection, study finds April 17th, 2014

Thinnest feasible membrane produced April 17th, 2014

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

High-temperature plasmonics eyed for solar, computer innovation April 17th, 2014

Announcements

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

High-temperature plasmonics eyed for solar, computer innovation April 17th, 2014

INSCX™ exchange to present Exchange trade reporting mechanism for engineered nanomaterials (NMs) to UK regulation agencies, insurers and upstream/downstream users April 17th, 2014

Transparent Conductive Films and Sensors Are Hot Segments in Printed Electronics: Start-ups in these fields show above-average momentum, while companies working on emissive displays such as OLED are fading, Lux Research says April 17th, 2014

Tools

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

Scientists Capture Ultrafast Snapshots of Light-Driven Superconductivity: X-rays reveal how rapidly vanishing 'charge stripes' may be behind laser-induced high-temperature superconductivity April 16th, 2014

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

Malvern reports on the publication of the 1000th peer-reviewed paper to cite NanoSight’s Nanoparticle Tracking Analysis, NTA April 16th, 2014

Military

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

Scalable CVD process for making 2-D molybdenum diselenide: Rice, NTU scientists unveil CVD production for coveted 2-D semiconductor April 8th, 2014

Rebar technique strengthens case for graphene: Rice University lab makes hybrid nanotube-graphene material that promises to simplify manufacturing April 7th, 2014

Photonics/Optics/Lasers

High-temperature plasmonics eyed for solar, computer innovation April 17th, 2014

Scientists Capture Ultrafast Snapshots of Light-Driven Superconductivity: X-rays reveal how rapidly vanishing 'charge stripes' may be behind laser-induced high-temperature superconductivity April 16th, 2014

Lumerical files a provisional patent that extends the standard eigenmode expansion propagation technique to better address waveguide component design. Lumerical’s EME propagation tool will address a wide set of waveguide applications in silicon photonics and integrated optics April 16th, 2014

Near-field Nanophotonics Workshop in Boston April 14th, 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