New sensor can detect E.coli in minutes
Canadian researchers have developed a new sensor that can detect E.coli bacteria in under 20 minutes, rather than hours in current technology.
September 7, 2016
by Canadian Packaging staff
According to a document found at the Optical Society (www.osa.org), scientists at the University of Quebec’s Photonics Research Center in Outaouais, Quebec led by Professor Wojtek Bock with help from the Indian Institute of Technology Kanpur in India, they have created sensor that is quicker and more cost-effective in its ability to detect the deadly E-coli bacteria over a wide temperature range.
Current technology involves on an amplification of the sample which can take several hours to days to detect the presence of the harmful bacteria.
E.coli bacteria is passed via contaminated food and water, affecting everyone, but particularly the elderly and children. Food can become contaminated with E. coli when animals are slaughtered or processed—despite the best precautions, but it can also be spread when handled by a person infected with the bacteria or from cross-contamination through unsanitary food handling practices.
E.coli can make the infected sick with severe stomach cramps, vomiting and diarrhea, with serious infections leading to kidney failure and death. A 2011 E.coli outbreak in Germany led to over 50 deaths and thousands of sick people. On September 3, 2016, a child in Scotland died from the bacteria infected in blue cheese, with some 20 other people ill.
The new E.coli sensor developed by the team utilizes bacteriophages—a virus, but one that attaches itself to the bacteria before killing it.
The bacteriophages are bonded to the surface of an optical fiber to grab hold of the E.coli bacteria from a sample. Once attached, a beam of light strikes the surface. If E.coli is detected, the light wavelength shifts.
Because temperature fluctuations can affect optical fibers for bacteria detection by altering the optical properties of the materials, sensors—which are designed to work at specific optimal temperatures can give bad readings if the sample gets too hot or too cold.
The Canadian-Indian research team added a optical component that canceling out temperature-induced shifts. Their device is temperature insensitive over an approximately 20°C (68-degree °F) range, starting at room temperature and going up to 40°C (104°F).
The better temperature insensitivity means that it can now be utilized for on-site monitoring, such as for water reservoirs, not to mention pathology labs and within the food industry.
As an added bonus, simply by changing the bacteriophage, other types of bacteria can be detected by the new sensor.
The researchers are working with Security & Protection International, Inc. of Ottawa, to further explore commercialization of their device, including inexpensive portable units.
Image of E.coli bacteria cells purchased via www.fotilia.com.