“Lab-on-a-Chip” Rapid Detection of Food Pathogens

Research Year: 
2010
Issue: 

Foodborne diseases are a widespread and growing public health problem, both in developed and developing countries. In the United States, for example, around 76 million cases of foodborne diseases, resulting in 325,000 hospitalizations and 5,000 deaths, are estimated to occur each year. Detecting waterborne and foodborne contaminants usually involves collecting a water or food sample, sending it to a laboratory and waiting for the samples to be filtered, incubated, tested and identified under a microscope. If a critical infection is suspected, say for highly dangerous E. coli O157:H7, the pathogen may already have multiplied and spread before the report arrives days later.

Description of Action: 

A series of “lab- on-a-chip” (LOC) applications in development at the Biosensors Laboratory at the University of Arizona can identify pathogens in minutes rather than days, using a simple device that delivers results locally. The LOC has microchannels filled with antibody-conjugated submicro- or nanoparticles that grow in size upon the presence of pathogens in a drop of water or food samples. The LOC is encased in a portable system that runs on a 9-V battery with no external computer. Testing pathogens involves minimal liquid handling—no centrifuging, micro-filtering or plating. One of the tests in development can detect pathogens—E. coli, Salmonella and potentially Cryptosporidium—in drinking water networks, irrigation systems, or wastewater recycling facilities and in food samples (lettuce, spinach or ground beef). A prototype handheld device has recently been fabricated that successfully detects near-single-cell E. coli from iceberg lettuce samples, as low as 10 cells per milliliter of “lettuce juice.”

Impact: 

Laboratory studies show that the LOC test is faster than conventional testing methods, taking an average of less than five minutes to deliver results on location. The degree of accuracy is three orders of magnitude greater than for conventional real-time or rapid tests (close to a single cell level). The method can be used to monitor early spread of pathogens, rather than being used after the outbreaks, thus potentially saving lives and money. The annual cost for foodborne illness in the U.S. is estimated to be $152 billion, according to a new report by Pew Charitable Trusts and Georgetown University.

Conact Name: 
Jeong-Yeol Yoon
Contact E-mail: