Researchers have developed a bio-sensor that can detect the presence of Escherichia coli in water within 20 minutes. This is much faster than traditional methods and could prevent serious outbreaks. The details are in a paper that was just published in the journal Optics Letters.
Escherichia coli bacteria are found everywhere and some strains can be dangerous to human health. Infections can be deadly, especially to children, the elderly, and the immunosuppressed. Water supplies can be monitored for the presence of E.coli bacteria but traditional methods can take days.
A research team adapted existing technology to develop a new sensor for detecting E.coli bacteria. They used bacteriophages, viruses that attack bacteria, and bonded them to an optical fiber. The bacteriophages are capable of grabbing onto any E.coli present in a water sample. Beams of light then hit the surface of the optical fiber. If the bacteriophages have attached themselves to E.coli, the wavelength will shift in a noticeable way. This allows for fast and easy detection of E.coli bacteria. Previous attempts using similar methods were not as successful due to the sensors only working in a limited range of temperatures. The team got around this problem by adding new technology that allows the sensor to work from room temperature up to 104° Fahrenheit.
The new sensor can detect the presence of E.coli within 15-20 minutes, much faster than current detection methods. The technology can also be adapted to detect other types of bacteria. Other bacterial strains can be detected by simply swapping out the bacteriophages. The team is currently working with a company called Security and Protection International, Inc. to commercialize their technology. The authors believe that their sensor will be an affordable alternative to existing devices. The sensor may be able to save lives by quickly detecting the presence of dangerous bacteria in food and water samples.
Dandapat, S. Tripathi, Y. Chinifooroshan, W. Bock and P. Mikulic. A compact and cost-effective temperature insensitive bio-sensor based on long period fiber gratings for accurate detection of E. coli bacteria in water. Optics Letters (2016).