If a harmful strain of E. coli bacteria is present in a food or water supply, then it's of the utmost importance to address the situation as fast as possible. Unfortunately, detection of the microbes involves tests that typically take several hours, and must be performed in a lab. That could soon change, however, as scientists have developed a portable sensor that can do the job in 15 to 20 minutes.
The device was created by researchers from Canada's University of Quebec, working with colleagues at the Indian Institute of Technology Kanpur. It utilizes viruses known as bacteriophages, which clasp onto and kill bacteria.
These viruses are bonded to the surface of an optical fiber within the sensor, where they're exposed to a sample of the substance being tested. If any E. coli are present in that sample, some of them will be grabbed by the bacteriophages. When a beam of light is subsequently shone through the fiber, the presence of the trapped bacteria will shift its wavelength. That shift is detected by the sensor, alerting users to the presence of the bacteria.
The device works at temperatures ranging from room temperature up to 40 ºC (104 ºF). Additionally, it can be altered to detect other types of bacteria, simply by substituting different types of bacteriophages.
Canadian company Security and Protection International, Inc. is currently collaborating with the scientists on commercializing the technology. It is hoped that the finished product will sell for no more than "a few thousand dollars."
A paper on the research was recently published in the journal Optics Letters.
Source: The Optical Society