A new device developed by researchers in India and Canada makes it possible to test food and bodies of water for bacterial contamination and produce conclusive results within minutes.
In a study featured in the journal Optics Letters, scientists at the Indian Institute of Technology Kanpur (IITK) and the University of Quebec described how they were able to create a sensor capable of detecting bacterial pathogens, such as E. coli, in food and water sources.
What makes the new technology revolutionary is that it allows researchers to confirm potential contamination within 15 to 20 minutes, which is much faster compared to the 24 hours or longer that it usually takes using other forms of diagnostics.
"Using currently available technologies, which are mostly based on amplification of the sample, it takes several hours to days to detect the presence of bacteria," study co-author Saurabh Mani Tripathi said. "A fast and accurate detection alternative is, therefore, preferable over the existing technology."
Faster Bacterial Contamination Testing
The new device makes use of viruses called bacteriophages that are known to latch onto certain forms of bacteria and kill them. The researchers bonded these microorganisms to the surface of optical fibers located at the center of the sensor.
If the bacteriophages happen to grab any bacteria from a sample, the light on the optical fibers will change to signify that it is indeed contaminated.
According to the researchers, they had to overcome limitations in using optical fibers to detect bacterial contamination. Such components are particularly vulnerable to changes in temperatures, which could make it difficult to get a concrete reading.
To remedy this, the developers added an extra optical component to the sensor that would cancel out any potential shifts caused by temperature changes. This allows the device to be used in outdoor settings such as in testing water reservoirs on site.
Researchers can adjust the new sensor in order to detect other bacterial strains aside from E. coli by simply changing the bacteriophages on the device.
Tripathi and his colleagues are now working with Canadian company Security and Protection International to produce the device for commercial use. They hope to produce portable versions that will only cost a few thousand dollars.
Bacterial contaminations continue to be one major public health concern. In 2015, several diners at Chipotle restaurants were sickened after eating food contaminated with E. coli.
Cases of listeria and salmonella contaminations have also led to mass recalls of food and other products from retail stores and supermarkets.
