Food
E. coli O157:H7 and Salmonella have been implicated in disease outbreaks due to the consumption of contaminated food and food products such as ground meats, fresh produce, fruit juices, and milk. These bacteria can occur naturally or can be intentionally introduced into the food supply, making rapid detection methods a priority in the food and dairy industries. Biosensors are able to provide rapid, accurate detection even in the most complex samples, enabling the identification of contaminated product before it gets to the consumer. Fluidics-based fiber-optic biosensors overcome problems such as particulate interference and the presence of inhibitors, eliminating the need for extensive sample preparation and enrichment.
ABL researchers have developed biosensor assays for the detection of E. coli O157:H7 in ground beef and apple juice, and for the detection of Salmonella in spent irrigation water used to irrigate sprouts. These assays can be performed within short time frames with a high degree of specificity, with limits of detection between 104 and 105 CFU/ml. In addition, both E. coli O157:H7 and Salmonella can be recovered from the fiber-optic waveguides used for biosensor detection, which is important for additional confirmatory testing and sample preservation. ABL researchers are expanding on the work 
with irrigation water from sprout seeds by creating a system linking the water concentrator developed at USF to a fiber-optic biosensor. This would allow continuous monitoring of water sources such as irrigation lines, enabling detection of produce contamination early in the handling process. An ATP bioluminescence immunoassay for the detection of E. coli O157:H7 and Salmonella in milk, ground beef, turkey, and chicken, and various citrus juices is also in development. Pathogen detection, identification, and viability can be determined from complex sample matrices within 5 hours.