New device quickly detects deadly bacteria in water

A team of Indian-origin researchers in Canada have developed an inexpensive device that can bring down the time required to detect the deadly E coli bacteria in drinking water from days to just a couple of hours.
"We have developed a hydrogel based rapid E coli detection system that will turn red when E coli is present," said Sushanta Mitra from York University in Canada.
"It will detect the bacteria right at the water source before people start drinking contaminated water," said Mitra.
The new technology has cut down the time taken to detect E coli from a few days to just a couple of hours. It is also an inexpensive way to test drinking water, which is a boon for developing countries, researchers said.

"This is a significant improvement over the earlier version of the device, the Mobile Water Kit, that required more steps, handling of liquid chemicals and so on," said Mitra.
"The entire system is developed using a readily available plunger-tube assembly. It is so user-friendly that even an untrained person can do the test using this kit," he added.

Traditional methods of testing for E coli contamination involves collecting water samples to send to an appropriate microbiological lab where the bacteria is cultured before a plate count is done to detect E coli presence, researchers, including Naga Siva Kumar Gunda and Ravi Chavali, also from York University, said.

The testing device uses the porous hydrogel matrix that cages specific enzymatic substrates that release certain enzymes in E coli cells, they said.
These enzymes then chemically react with the substrates to change colour. If there is no E coli, the colour of the hydrogel will not change, as there is no chemical reaction, researchers said.
The results of the water test can be instantly broadcast using a mobile app already developed by the researchers.
The findings were published in the journal Analyst.