"...our technology potentially can be used by minimally trained food and agricultural workers to detect arsenite (and eventually other contaminates) in a liquid food matrix..."
Continuous monitoring of chemical agents in aqueous media using bioreporter-based sensors
Investigators: David E Nivens (Department of Food Science), Michael Franklin (Center for Biofilm Engineering, Montana State University), Carlos Corvalan (Department of Food Science)
Project Report 2007 - 2008
Chemical contamination of our food supply threatens the heath of consumers and has become a major concern. As societies become more populated and technologically-advanced, sources of pollution and the potential for contamination (inherent, unintentional, or intentional) are increasing. Inexpensive sensors that have analytical capabilities of detecting harmful chemicals in food would facilitate our nation's ability to protect its food supply and minimize health concerns associated with contamination. We proposed to develop bioreporter-based chemical sensors consisting of genetically programmed cells (bioreporters), a disposable cartridge system containing the bioreporters, and a detection/communication module for Web-based and/or networked-based assessment capabilities. With the successful development of this technology, we anticipate that the bioreporter-based chemical sensors will have the analytical capabilities required to fill a critical need in the food industry. In addition to being potentially inexpensive, these biosensors are being developed to detect a hazardous chemical below immediately dangerous to health of life (IDHL) limits, minimize false positives and negatives, have rapid response times, and be simple to use. We envision that the sensors could be used with standard food defense practices to further facilitate a safe food supply.
- Develop a dual-signaling bioreporter that minimizes false negatives by using bioluminescence and fluorescence signal for hazardous chemical detection.
- Develop a microenvironment that contains programmable cells and nutrients to increase the stability and extend the lifetime of the biosensor.
- Construct novel bioreporters with optimal analytical performance for point-of-use and long-term monitoring experiments.
- Model the systems to improve all aspects of analytical performance and develop application-specific biosensors for food and agriculture systems.
Bioreporter-based chemical sensor technology was used to quantify arsenite concentrations (one of the most hazardous forms of arsenic) in liquid food matrices including milk, fruit juices, and bottled water with minimal or no sample preparation. For example, various amounts of arsenite were spiked into the undiluted apple juice samples (arsenite is a common contaminate found in apple orchards). An aliquot of each sample was then exposed to the sensor to generate time-dependent linear calibration curves. Results showed that apple juice samples with 10 parts per billion (µg/L) arsenite could be quantified in less than 2 hours. Web- and network-based software was developed to monitor the responses of the bioreporter-based sensors and generate a warning signal when the analyte concentration exceeded a predetermined alarm level. These findings indicate that our technology potentially can be used by minimally trained food and agricultural workers to detect arsenite (and eventually other contaminates) in a liquid food matrix at or below chronic and acute minimal risk levels.