Sensor can detect E. coli and other bacteria in 15–20 minutes

The speedy and cost-effective detection of E. coli would be a boon to food and beverage processors everywhere. Most current detection technologies rely on amplification of the bacteria within the sample, which takes anything from several hours to several days, but now researchers have developed a sensor that can deliver results in 15–20 minutes.

Researchers from the Photonics Research Center at the University of Quebec in Outaouais, Canada, under direction of Professor Wojtek J Bock and collaborators from the Indian Institute of Technology Kanpur, have bonded bacteriophages to the surface of an optical fibre. Here, the viruses collect E. coli bacteria from the sample under test and keep them attached. When a beam of light strikes the surface, the presence of E. coli shifts the wavelength, which indicates the level of bacterial contamination.

By changing the bacteriophage, the sensor can be modified to detect other strains of bacteria.

In most circumstances temperature changes also induce wavelength changes, but this problem was circumvented by the addition of an optical component that cancels out temperature-induced shifts in temperature ranges from ambient to 40°C.

Security and Protection International is already collaborating with the researchers with a view to commercialising portable sensors with prices around a few thousand dollars.

The researchers describe the sensor in a paper in the journal Optics Letters, from The Optical Society.