Researchers at Jackson State University have been working to develop the technology which uses antibody-covered gold nanoparticles to detect the presence of Salmonella microbes on the surface of food. The same technology can then be used to kill the pathogen.
The Mississippi-based researchers were able to attach Salmonella antibody molecules to the gold nanoparticles, which attach to the outer surface of Salmonella microbes when they encounter the pathogen.
Several of the modified nanoparticles can attach to one microbe, allowing the easy detection of the gold nanoparticle-antibody-Salmonella structures.
The method, which is suitable for field-based analysis, has already been modified to identify the presence of other pathogens including E.coli.
“Very little gold”
Head researcher Paresh C. Ray told FoodQualityNews.com, that once commercialised, the patent-pending development will offer the industry a quick and surprisingly cheap Salmonella detection option.
“Using this technique we can detect pathogens such as Salmonella very fast,” he said.
According to Ray, some traditional testing methods can take up to 72 to complete, whereas the gold-nanoparticle test can identify Salmonella microbes within five minutes – fulfilling the urgent need for faster detection.
“As well as that, anybody can use this method, it doesn’t take a trained technician or require specialist training to use it. This could make it ideal for field-based detection.”
Despite its status as a precious metal, only small amounts of gold are actually needed for each individual test, Ray added.
“From about $90 or $100 worth of gold we can make gallons of the gold nanoparticle solution. Very little gold is actually needed in each test.”
Only a few drops of the solution are then needed to detect the pathogen in question.
Detect and kill
“We are making gold nanoparticles that are modified with anti-bodies of bacteria. By doing this we can use the gold nanoparticles to detect harmful bacteria and kill them,” he said.
When a specific wavelength of light is shone at the nanoparticles, they gold absorbs the heat, which in turn burns through the outer membrane of the Salmonella bacteria – killing it.
“The process has a double use. It can detect and then kill them by heating the gold nanoparticles which in turn kills the bacteria.”
“We are working with different companies to secure a grant, from there we will look to commercialise the product and bring the device to the market,” concluded Ray.