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.