The objective to be accomplished in the next three years is the development and demonstration of an inexpensive, easy to use, accurate biosensor that is capable of detecting contamination of fresh fruits and vegetables with Salmonella. The biosensors will be placed directly on the surface of fresh vegetables such as spinach, in-the-field, and then interrogated wirelessly to determine whether the spinach leaves are contaminated with Salmonella. Data from these sensors will be used to spatially and as a function of time, track Salmonella contaminations. By monitoring Salmonella contamination as a function of location in the field and time, critical hazard points can be identified and best farming, harvesting and transportation practices developed to improve the food safety of fresh produce crops.
NON-TECHNICAL SUMMARY: The U.S. food system is highly efficient and provides the American consumer with one of the most diverse, abundant, and economical food supplies in the world. However, our food system is a complex farm-to-fork continuum, with multiple and ever-changing supply chains to meet consumers' demands. Therefore, protecting the U.S. food supply from terrorist attacks requires a concerted system approach. Agro-terrorism can result from an intentionally introduced biological, chemical, or nuclear agent that would devastate people, animals, or crops. The detection of agro-terrorism agents that may be used to contaminate our food supply and disrupt commerce is therefore a high priority. The most likely agro-terrorism agents that may be used in food fall into three classes: biological toxins (Ricin, Clostridium botulinum toxin, Staph toxin, and Aflatoxin); living pathogens (E. coli O157:H7, Salmonella, Listeria), and spores (anthrax, C. botulinum). Our Center has developed sensors for the detection of living agents such as E. coli and Salmonella and spores of Bacillus anthracis. Research has been initiated on the detection of toxins (Ricin and botulinum toxin) in addition to continuing work on living pathogens such as Salmonella, E.coli, Listeria, and Bacillus anthracis. <P>
APPROACH: The three-year objective of this project is to develop and demonstrate an inexpensive, easy to use, accurate biosensor that is capable of directly detecting contamination of fresh produce (spinach and lettuce) with bacterial pathogens such as Salmonella and E. coli. To aid in the completion of the above objective, the research has been divided into four separate tasks: Task A: Biomolecular Recognition Elements, Improve phage display technology for pathogen detection; Task B: Biomolecular Recognition Elements and Sensor Platform, Improve biocompatibility of "dust size" biosensors; Task C: Biosensor Platform and System, Develop a handheld device to interrogate the "dust sensors;" and Task D; In-field Detection of Pathogens, Direct detection of pathogens on vegetables. The biosensors will be placed directly on the surface of the fresh produce and then interrogated wirelessly to determine whether the produce is contaminated with Salmonella. Data from these sensors will be used to spatially and as a function of time, track pathogen contaminations. In this manner potential sources of contamination such as run-off from heavy rains, compost piles, contaminated pond water, or applications such as organic fertilizers can be identified and incorporated into an integrated growth, harvest and transportation management plan to insure safe food products. The biosensors will be constructed using wireless, microelectronically fabricated magnetoelastic resonators as the transducer. Highly robust and specific, genetically-engineered, phage will be immobilized onto the resonators as the bio-molecular recognition element. The biosensors will be smaller than a dust particle and cost less than 1/1000 of a cent.