Salmonella sensing system: New approach to detecting food contamination enables real-time testing

October 18, 2013
This is an image of the new sensor. Credit: APL

As anyone who has ever consumed bacteria-contaminated food and experienced "food poisoning" can tell you, it's a miserable experience. Yet it's an all-too-common one, with foodborne illnesses making 1 in 6 Americans—or 48 million people—sick each year. Of these people sickened, 128,000 end up in the hospital, according to the Centers for Disease Control and Prevention, while 3,000 die.

Foodborne illnesses spread easily and, as such, are a difficult-to-control problem—even more so in developing nations. This means that quick detection can play a critical role in halting the spread of contamination. Traditional detection methods, however, tend to be haltingly slow.

Recognizing the need for a real-time biosensing system to detect pathogenic bacteria, such as Salmonella, a team of Auburn University researchers came up with a novel design, which they describe in the American Institute of Physics' Journal of Applied Physics.

What sets this biosensing system apart from traditional detection methods is a design that involves using a magnetoelastic biosensor—a low-cost, wireless acoustic wave sensor platform—combined with a surface-scanning coil detector. The biosensors are coated with a bacteria-specific recognition layer containing particles of "phage," a virus that naturally recognizes bacteria, so that it's capable of detecting specific types of .

Traditional technologies required the sensor to be inside a coil to measure the sensor's signals, said Yating Chai, a doctoral student in Auburn University's materials engineering program.

"The key to our discovery is that measurement of biosensors can now be made 'outside the coil' by using a specially designed microfabricated reading device," he explained.

"In the past, if we were trying to detect whether or not a watermelon was contaminated with Salmonella on the outside of its surface, the sensors would be placed on the watermelon, and then passed through a large surrounding it to read the sensors," Chai says.

By stark contrast, the new system is a handheld device that can be passed over food to determine if its surface is contaminated.

"Now, tests can be carried out in agricultural fields or processing plants in real time—enabling both the and processing plant equipment and all surfaces to be tested for contamination," notes Chai.

Explore further: Biosensing tool to detect salmonella holds promise for preventing common food poisoning

More information: The paper, "Design of a surface-scanning coil detector for direct bacteria detection on food surfaces using a magnetoelastic biosensor," authored by Yating Chai et al., appears in the American Institute of Physics' Journal of Applied Physics. See:

Related Stories

Device speeds concentration step in food-pathogen detection

October 14, 2013

( —Researchers have developed a system that concentrates foodborne salmonella and other pathogens faster than conventional methods by using hollow thread-like fibers that filter out the cells, representing a potential ...

Recommended for you

A new form of real gold, almost as light as air

November 25, 2015

Researchers at ETH Zurich have created a new type of foam made of real gold. It is the lightest form ever produced of the precious metal: a thousand times lighter than its conventional form and yet it is nearly impossible ...

Getting under the skin of a medieval mystery

November 23, 2015

A simple PVC eraser has helped an international team of scientists led by bioarchaeologists at the University of York to resolve the mystery surrounding the tissue-thin parchment used by medieval scribes to produce the first ...

Moonlighting molecules: Finding new uses for old enzymes

November 27, 2015

A collaboration between the University of Cambridge and MedImmune, the global biologics research and development arm of AstraZeneca, has led researchers to identify a potentially significant new application for a well-known ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.