New paper strip test detects E. coli quickly, cheaply and simply
By Darren Quick
April 30, 2012
Nothing can put a dampener on a summer holiday like a coliform bacteria outbreak. But even worse than being told to keep out of the water in the event of an outbreak is not being told to keep out of the water in the event of an outbreak and ending up paying the price. Researchers at McMaster University have now developed a paper strip test that is cheap to produce, extremely portable, simple to use, and detects E. coli in water in 30 minutes.
While many popular recreational waters are regularly tested for coliform outbreaks, the methods used are generally slow and cumbersome, with samples often having to be sent to a lab for amplification before testing. The new paper strips developed at McMaster overcome all these problems. They work quickly, they are portable, they are simple to use, and they are cheap and easy to produce.
Using inkjet-printing technology, the paper strips are coated with chemicals that change color in the presence of E. coli. Concentrations of the bacteria are indicated by different colors on the strip. While the strips can quickly indicate if water is safe for swimming, they aren’t sensitive enough to identify if it is safe for drinking – a standard that is hundreds of times tighter than for safe swimming water.
However, the McMaster team, led by chemistry professor John Brennan, is planning to conduct field-testing on the prototype strips to help in their refinement that may lead to the development of strips capable of testing the safety of drinking water.
The test strips have been validated by scientists from the Sentinel Bioactive Paper Network, which receives funding from the National Sciences and Engineering Research Council of Canada (NSERC). The NSERC is now funding the next stage of pre-commercial development of the strips, with a possibility the final product will become commercially available in two to three years.
The team's research is detailed in a paper appearing online in the journal Analytical and Bioanalytical Chemistry.
Source: McMaster University