Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The Smallest Sight: Researchers Zoom In on the Nanoscale

04.03.2003


Researchers at the University of Rochester have created the highest resolution optical image ever, revealing structures as small as carbon nanotubes just a few billionths of an inch across. The new method should open the door to previously inaccessible chemical and structural information in samples as small as the proteins embedded in a cell’s membrane. The research appears in today’s issue of Physical Review Letters.



"This is the highest resolution optical spectroscopic measurement ever made," says Lukas Novotny, professor of optics. "There are other methods that can see smaller structures, but none use light, which is rich in information. With this technique we have a detailed spectrum for every point on a surface."

Since light is so rife with information (everything we know about the deep universe comes from teasing information from a tiny amount of light), Novotny and his colleague, visiting professor Achim Hartschuh, can determine what a piece of material is made of as well as its structure. Is the string of carbon rolled into a tube or just a string of atoms? Is a protein made of expected molecules and properly folded to be an effective medicine? And what could be the most rewarding result of the research-detecting properties of such small structures that were unknown before. Novotny and his team are also eager to learn if certain structures exhibit unknown characteristics, such as when carbon nanotubes, for instance, cross or interconnect.


The ultimate vision for the Raman microscopy project, however, is to refine the process to a point where it might revolutionize biology. "Identifying individual proteins right on the cell’s membrane has been the goal of this project from the start," says Hartschuh. Garnering the cornucopia of information light provides from the proteins on a membrane would mean scientists could understand exactly how a cell’s membrane works, opening the door to designer medicines that could kill harmful cells, repair damaged cells, or even identify never-before-seen strains of disease.

The Rochester team’s technique, called near-field Raman microscopy, illuminates the nano-sized structures with light, allowing researchers to glean far more information than any other technique. Other ultra-high resolution imaging techniques, such as atomic force microscopes, only detect the presence of objects, they don’t "see" them. Though researchers have longed wished to use light at such magnification, the laws of physics make this extremely difficult. Light travels in waves, and if an object like a nanotube or a protein is much smaller than that wavelength, it’s like trying to pick up a poppy seed with a fork-the poppy seed falls between the tines. Some efforts have been made to force light to shorter wavelengths and through tiny apertures, but these methods have their own built-in limitations, including damage to the aperture itself.

Novotny and Hartschuh sharpen a gold wire to a point just a few billionths of an inch across. A laser then shines against the side of the gold tip, inciting electrons inside it to oscillate. These oscillations create a tiny bubble of electromagnetic energy at the tip, which interacts with the vibrations of the atoms in the sample. This interaction, called Raman scattering, releases packets of light from the sample at specific frequencies that can be detected and used to identify the chemical composition of the material.

In about two years, Novotny and Hartschuh think they will be able to refine the system, already with a resolution of 20 nanometers (billionths of a meter), so that they can image proteins, which are only 5 to 20 nanometers wide. To do that they will try to get the point of the gold tip sharper still, or even experiment with different shaped points. Then the trick will be keeping the tip "alive," meaning using it without incurring the least damaging bump or scrape-a difficult task when hovering only a few nanometers above the scanned sample. If all goes well, the research team may try to push the technology even further to derive first-ever optical images of smaller molecules.

The research was supported by a grant from the National Science Foundation.

Jonathan Sherwood | University of Rochester
Further information:
http://www.rochester.edu/pr/News/NewsReleases/scitech/novotny-nearfield.html

More articles from Physics and Astronomy:

nachricht Scientists reach back in time to discover some of the most power-packed galaxies
28.02.2017 | Clemson University

nachricht From rocks in Colorado, evidence of a 'chaotic solar system'
23.02.2017 | University of Wisconsin-Madison

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Safe glide at total engine failure with ELA-inside

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded after a glide flight with an Airbus A320 in ditching on the Hudson River. All 155 people on board were saved.

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded...

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Scientists reach back in time to discover some of the most power-packed galaxies

28.02.2017 | Physics and Astronomy

Nano 'sandwich' offers unique properties

28.02.2017 | Materials Sciences

Light beam replaces blood test during heart surgery

28.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>