Researchers Present Rapid Salmonella Test at ACS Meeting

Researchers from Jackson State University in Mississippi have reportedly developed a rapid test for detecting Salmonella on food that uses popcorn-shaped gold nanoparticles. Presented March 27, 2012, at the 243rd National Meeting and Exposition of the American Chemical Society (ACS), the application relies on antibodies attached to gold nanoparticles that then transfer to Salmonella bacteria if present, in the process changing color from pink to blue.

“The test for lettuce requires just a tiny sample of lettuce leaf,” explained lead researcher Paresh Ray. “It doesn’t take a trained laboratory technician to perform the test or read the results. If the color changes from pinkish to bluish, that signals the presence of Salmonella. The test is suitable for use in farm fields and in remote areas of the developing world. We believe it may have enormous potential for rapid, on site pathogen detection to avoid the distribution of contaminated foods.”

Although they are still testing the solution’s long-term toxicity and overall safety, the researchers have meanwhile used the technique to detect other microbes such as E. coli, speculating that the mechanism could also serve to eliminate bacteria altogether. “When you shine the right wavelength of light into contaminated water, for instance, the gold nanoparticles absorb that light and heat up. Those hot particles burn through the outer membrane of the Salmonella bacteria, killing the bacteria,” Ray was quoted as saying. See ACS Press Release, March 27, 2012.