Very quick sensing of food pathogens employs liquid crystals

Citation

(2012), "Very quick sensing of food pathogens employs liquid crystals", Sensor Review, Vol. 32 No. 2. https://doi.org/10.1108/sr.2012.08732baa.003

Very quick sensing of food pathogens employs liquid crystals

Article Type: Mini features From: Sensor Review, Volume 32, Issue 2

Researchers at Kent State University (Ohio) and the Northeast Ohio Medical University have developed a biosensor technology that exposes liquid crystals to pathogens such as food pathogens E. coli and then inserts them into an electronic reader. In less than 30 min, the reader can signal the presence or absence of many food pathogens.

Previously, detection of such pathogens took days of growing them on a culture dish to identify them. Since food safety is an increasingly urgent task, quick assessment can save many lives. In the US alone, the Centers for Disease Control estimate each year that 48 million people are affected by food-borne pathogens resulting in 128,000 hospitizations and as many as 3,000 deaths.

The technology has been licensed to Crystal Diagnostics which is developing the commercial biosensor based on the liquid crystal technology (Figure 11). Their MultiPath™ system can detect three different food pathogens at the same time, such as E. coli, Salmonella or Listeria. Just in 2011 there have been major events such as meat contamination in Germany and melon contamination in the USA.

Figure 11 Crystal Diagnostics MultiPath™ food pathogen detection sensor cartridge ready for insertion into the reader

The technology employs a cassette containing five individual crystal cells, two are control cells and three are test cells. The food item to be tested is prepared by mixing the food with liquid crystal and an antibody or antibody cocktail for the pathogen being sought. The cassette is then inserted into the reader. If pathogens are present, they disrupt the alignment of the crystals in the test cells and in about 30 min the results are known.

The 2011 meat scare in Germany resulted in millions of kilos of meat being recalled at great expense as there was no quick way to identify contaminated meat. In a recent melon Listeria contamination in the USA, 25 people died before the source was found. For more information about liquid crystal-based MultiPath system please contact the web site: www.crystaldiagnostics.com. For more information about the liquid crystal developments at Kent State University please contact the web site: www.kent.edu