A research team led by Bryan Chin, director of the Auburn University Detection and Food Safety Center, has developed a cheap, portable, and easy-to-use new screening tool to test fresh fruits and vegetables for the presence of bacteria that can cause foodborne illnesses. Currently available screening methods for produce can be costly in terms of time, equipment, and expertise. The multidisciplinary research team of engineers, microbiologists, and genomicists based at Auburn University and the University of Georgia wanted to create a new method that could be used more broadly.
The team has developed biosensors that are placed directly upon the fresh fruits or vegetables being analyzed. The eyelash-size biosensors are coated with antibodies and phages (viruses that target specific bacteria) and vibrate when placed within an oscillating magnetic field. If targeted bacteria are present, they bind to the antibodies and phages and change the vibration frequency of the biosensor. These frequency changes help inspectors determine the type and amount of bacteria on a given fruit or vegetable.
“The technology gives us a revolutionary new capability to directly detect food pathogens,” Chin said. It is fast and has both high specificity and sensitivity. In less than 12 minutes, the sensors can detect as few as five hundred Salmonella cells amid a sea of a million bacterial cells. The measurement system costs $750, with each of the disposable biosensors costing less than 1/1000 of a cent.
The biosensors are still in the research and development stage, but moving forward, Chin has his sights set on developing a technology that is even faster and is capable of screening an entire bulk shipment of product, removing sub-sampling entirely.
The research was conducted thanks in part to a grant from the U.S. Dept. of Agriculture’s National Institute of Food and Agriculture (USDA NIFA).