Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Silver bullet: UGA researchers use laser, nanotechnology to rapidly detect viruses

17.11.2006
Waiting a day or more to get lab results back from the doctor’s office soon could become a thing of a past. Using nanotechnology, a team of University of Georgia researchers has developed a diagnostic test that can detect viruses as diverse as influenza, HIV and RSV in 60 seconds or less.

In addition to saving time, the technique – which is detailed in the November issue of the journal Nano Letters – could save lives by rapidly detecting a naturally occurring disease outbreak or bioterrorism attack.

“It saves days to weeks,” said lead author Ralph Tripp, Georgia Research Alliance Eminent Scholar in Vaccine Development at the UGA College of Veterinary Medicine. “You could actually apply it to a person walking off a plane and know if they’re infected.”

The technique, called surface enhanced Raman spectroscopy (SERS), works by measuring the change in frequency of a near-infrared laser as it scatters off viral DNA or RNA. This change in frequency, named the Raman shift for the scientist who discovered it in 1928, is as distinct as a fingerprint.

This phenomenon is well known, but Tripp explained that previous attempts to use Raman spectroscopy to diagnose viruses failed because the signal produced is inherently weak.

But UGA physics professor Yiping Zhao and UGA chemistry professor Richard Dluhy experimented with several different metals and methods and found a way to significantly amplify the signal. Using a method they’ve patented, they place rows of silver nanorods 10,000 times finer than the width of a human hair on the glass slides that hold the sample. And, like someone positioning a TV antenna to get the best reception, they tried several angles until they found that the signal is best amplified when the nanorods are arranged at an 86-degree angle.

“The enhancement factors are extraordinary,” Dluhy said. “And the nice thing about this fabrication methodology is that it’s very easy to implement, it’s very cheap and it’s very reproducible.”

Tripp said the technique is so powerful that it has the potential to detect a single virus particle and can also discern virus subtypes and those with mutations such as gene insertions and deletions. This specificity makes it valuable as a diagnostic tool, but also as a means for epidemiologists to track where viruses originate from and how they change as they move through populations.

The researchers have shown that the technique works with viruses isolated from infected cells grown in a lab, and the next step is to study its use in biological samples such as blood, feces or nasal swabs. Tripp said preliminary results are so promising that the researchers are currently working to create an online encyclopedia of Raman shift values. With that information, a technician could readily reference a Raman shift for a particular virus to identify an unknown virus.

To make their finding commercially viable, they’re developing a business model, seeking venture capital and exploring ways to mass produce the silver nanorods. Next year, they plan on moving their enterprise to the Georgia BioBusiness Center, an UGA incubator for startup bio-science companies.

Presently, viruses are first diagnosed with methods that detect the antibodies a person produces in response to an infection. Tripp explained that these tests are prone to false positives because a person can still have antibodies in their system from a related infection decades ago. The tests are also prone to false negatives because some people don’t produce high levels of antibodies.

Because of these limitations, antibody based tests often must be confirmed with a test known as polymerase chain reaction (PCR), which detects the virus itself by copying it many times. The test can take anywhere from several days to two weeks. Tripp said the latter is clearly too long, especially in light of emerging threats such as H5N1 avian influenza.

“For some respiratory viruses, you’ve either cleared the infection at that point or succumbed to the infection,” Tripp said. “What we’ve developed is the next generation of diagnostic testing.”

Sam Fahmy | EurekAlert!
Further information:
http://www.uga.edu

More articles from Physics and Astronomy:

nachricht Seeing the quantum future... literally
16.01.2017 | University of Sydney

nachricht Airborne thermometer to measure Arctic temperatures
11.01.2017 | Moscow Institute of Physics and Technology

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: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>