Sensor detects E. coli more quickly, in more environments

Scientists have developed a new sensor capable of detecting E. coli 20 minutes more quickly than conventional laboratory testing methods. The sensor also works in a variety of different environments where the bacteria could be found.

After an E. coli outbreak in Germany infected thousands of people and killed 50 in 2011, scientists set out to develop a tool capable of detecting the bacteria in a wide range of environments and temperatures. Researchers from Canada's Photonics Research Center at the University of Quebec partnered with the Indian Institute of Technology Kanpur developed a tool using bacteriophages and optical fibers.

"Pathogenic bacterial infection is one of the biggest causes of death, and a fast response time is much needed for timely detection and subsequent cure of bacterial infection," said Saurabh Mani Tripathi, a physicist at the Indian Institute of Technology Kanpur. “Faster tests for the bacteria could lead to faster treatment of patients, as well as to cheaper and easier environmental monitoring.”

The sensor uses bacteriophages—viruses that grab and kill bacteria—attached to an optical fiber to deliver light and show the different wavelengths that appear where E. coli is present. Optical fibers are often manipulated by changes in temperature and can give inaccurate readings; to combat this challenge, the researchers added another optical component that can cancel out temperature-induced shifts.

The sensor can now detect E. coli over a 68-degree range.

“The temperature insensitivity makes the sensor more practical for outdoor applications, like onsite monitoring of water reservoirs,” said Tripathi.