Researchers have shown that a fluorescence detection system that doesn’t contain any lenses can provide highly sensitive detection of deadly microorganisms in drinking water. With further development, the new approach could provide a low-cost and easy-to-use way to monitor water quality in resource-limited settings such as developing countries or areas affected by disasters. It could also be useful when water safety results are needed quickly, such as for swimming events, a concern highlighted during the Paris Olympics.
“In developing countries, unsafe water sources are responsible for more than one million deaths each year,” said research team leader Ashim Dhakal from the Phutung Research Institute in Nepal. “We hope that our work will facilitate the development of simpler and cost-effective yet highly efficient sensing paradigms for drinking water, saving countless lives around the world.”
Current methods used to assess microbial contamination in water require culturing the water samples and then quantifying harmful bacteria. This can take over 18 hours, making it impractical when immediate confirmation of water safety is needed. This is also a key reason why water surveillance is ineffective in developing countries, where the required skilled human resources, infrastructure and reagents are not readily available.
In Optica, Optica Publishing Group’s journal for high-impact research, researchers from Phutung Research Institute, University of São Paulo in Brazil and University of York in the UK report that their new water monitoring fluorometer can detect fluorescent proteins from bacteria in water down to levels of less than one part per billion, without using any lenses. This sensitivity meets the World Health Organization’s criteria for detecting fecal contamination in drinking water.
“Today’s fluorometers typically use costly lenses that are made of specialty UV-transparent glass and require precise positioning,” said Dhakal. “We show that eliminating the lenses not only reduces the device cost, size and weight but also provides better performance given that we are not aiming for imaging here.”
By Optica