It seems gold nanoparticles have enabled a number of medical breakthroughs recently. Last month, we covered research that relied on gold nanoparticles in conjunction with lasers to restore sight in the blind. Earlier in the year, we ran stories on the use of the nanomaterial as a drug carrier for cancer treatment and for cancer detection.
Now, researchers from the University of Georgia report that gold nanoparticles could be used to rapidly diagnose the flu (influenza). The detection method, which is described in the August edition of the Analyst, makes use of gold nanoparticles coated with antibodies, which in turn bind to certain strains of the flu virus. By gauging how the particles scatter laser light, the scientists were able detect the presence of influenza in a sample within minutes. The test, which the researchers predict will eventually be used at the point-of-care, also has the advantage of being inexpensive. The cost per exam is reportedly one-hundredth of a cent.
The test works by taking advantage of gold nanoparticles’ ability to efficiently scatter light. A commercially available device measures the intensity of light passed through the viruses and nano particles. Because viruses are relatively poor light scatterers, the light passed through the solution fluctuates in a predictable pattern, which enables the technology to detect influenza.
The scientists contrast the test with polymerase chain reaction (PCR) and lateral flow assay. As the press release explains:
The researchers noted that the current standard for definitively diagnosing flu is a test known as PCR, for polymerase chain reaction. PCR can only be done in highly specialized labs and requires that specially trained personnel incubate the sample for three days, extract the DNA and then amplify it many times. The entire process, from sample collection to result, takes about a week and is too costly for routine testing.
The alternative is a rapid test known as a lateral flow assay. The test is cost effective and can be used at the point-of-care, but it can’t identify the specific viral strain. It also misses up to 50 percent of infections and is especially error-prone when small quantities of virus are present, Driskell added.
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.
“This test offers tremendous advantages for influenza, but we really don’t want to stop there,” Tripp said. “Theoretically, all we have to do is exchange our anti-influenza antibody out with an antibody for another pathogen that may be of interest, and we can do the same test for any number of infectious agents.”