Functional Durability Of A Quartz Crystal Microbalance Sensor For The Rapid Detection Of Salmonella In Liquids From Poultry Packaging

Abstract

Foodborne disease causes an estimated 4 to 76 million cases of food poisoning with 5,000 associated deaths annually in the United States at a cost of $6.5 –34.9 billion. In poultry products, Salmonella is the most common pathogenic bacterial contaminant, and is responsible for the highest percentage of foodborne disease transmission. Currently, microbial detection performed by the food industry is inadequate; tainted food products routinely are sold and consumed before contamination is revealed. A rapid, sensitive (350 ± 150 cells ml–1) quartz crystal microbalance biosensor, layered with heat-treated anti-Salmonella-phospholipid monolayers by the Langmuir-Blodgett technique, has been evaluated by immersion testing in chicken exudate to determine the feasibility of inclusion into processed poultry packaging. Biosensor degradation and bacterial interaction were examined under darkfield microscopy and scanning electron microscopy. Results indicate that the biosensor is specific (r ³0.98), and sensitive (³10 mV decade-1) for up to 32-40 hours post-immersion at 4°C with an assay time of less than 7 minutes. The working longevity of the biosensor was not increased through filter-sterilization of chicken exudate. Heat-treated antibodies (56°C for 30 minutes) were required to prepare a properly functioning sensor. Observations of bacterial interaction with the monolayer by scanning electron microscopy and darkfield microscopy agreed well with the functional duration of the biosensor. The results of the evaluation suggest the potential feasibility of using the biosensor in processed poultry packaging as a preemptive tool for the rapid, specific, and sensitive detection of Salmonella.