Gold nanoparticles can diagnose flu in minutes, and cheaply

Aug. 4, 2011

University of Georgia researchers developed a new, low-cost flu detection method that couples accuracy and speed—both of which are critical during flu outbreaks and have never been available in the same test.

University of Georgia (Athens, GA) researchers developed a new, low-cost flu detection method that couples accuracy and speed—both of which are critical during flu outbreaks and have never been available in the same test. The method involves coating gold nanoparticles with antibodies (immune system proteins) that bind to specific strains of the flu virus and then measuring how the particles scatter laser light, enabling flu detection in minutes and costing only a fraction of a penny per exam.

In the study, which was published in the August edition of the journal Analyst, study co-authors Ralph Tripp and Jeremy Driskell, both of the UGA College of Veterinary Medicine, linked antibodies with gold nanoparticles. The gold nanoparticle-antibody complex aggregates with any virus present in a sample, and a commercially available device measures the intensity with which the solution scatters light.

Driskell explained that gold nanoparticles are extremely efficient at scattering light. But biological molecules such as viruses are intrinsically weak light scatterers. So, clustering of the virus with the gold nanoparticles causes the scattered light to fluctuate in a predictable and measurable pattern.

Driskell notes that the test can be done at the point-of-care and the amount of gold that it uses is less than what would fit on the head of the pin, costing around one-hundredth of a cent per test.

By overcoming the weaknesses of existing diagnostic tests, the researchers hope to enable more timely diagnoses that can help halt the spread of flu by accurately identifying infections and allowing physicians to begin treatment early, when antiviral drugs, such as Tamiflu, are most effective.

Tripp and Driskell are planning to compare the new diagnostic test with another that Tripp and his colleagues developed that measures the change in frequency of a laser as it scatters off viral DNA or RNA. Tripp also is working to adapt the new technique so that poultry producers can rapidly detect levels of salmonella in bath water during processing. Poultry is the largest agricultural industry in Georgia, he points out, so the technology could have a significant impact on the state’s economy.

Not wanting to stop at flu detection with the test, Tripp notes that other antibodies for other pathogens that may be of interest could be used to do the same test for any number of infectious agents.

-----

Posted by Lee Mather

Follow OptoIQ on your iPhone; download the free app here.

Subscribe now to BioOptics World magazine; it's free!