Fibre optic sensor offers rapid detection of E.coli bacteria

The team from the Photonics Research Center at the University of Quebec, under direction of Prof Wojtek J. Bock and collaborators from the Indian Institute of Technology Kanpur, built the new sensor that can detect E.coli over a wide range of temperatures. The researchers describe the sensor in a paper in Optics Letters.

"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. A fast and accurate detection alternative is, therefore, preferable over the existing technology," 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, he said.

The new sensor uses bacteriophages, which are viruses that latch onto and kill bacteria. The viruses are bonded to the surface of an optical fibre and will seize E.coli bacteria from a sample and keep them attached. When a beam of light strikes the surface, the presence of E.coli shifts the wavelength, which signals bacterial contamination.