At first, minty-fresh breath strips vowed to transform the way people prepared for a make-out session. But researchers say that the sugary, flexible material is actually capable of far more. The same stuff we use to freshen our breath could soon be deployed to detect dangerous chemicals and bacteria in drinking water.
Whether it’s foggy, flammable, or full of tiny, unidentifiable floaters, contaminated water poses one of the biggest threats to people drinking out of rural wells. In a country like India, which makes up the 12th largest pesticide market in the world, dangerous cancer and neurological disorder-causing chemicals have infiltrated groundwater. And often there’s no way to tell.
McMaster University chemical engineering professor Carlos Filipe and his students were trying to come up with a simple, fast, and cheap way to test water when one of the students suggested something creative: Why not try to embed the water detection technology in dissolvable breath freshener strips? An experiment that started with a trip to the drug store ended with the discovery that tiny pills made of pullulin, the gelatinous, fungus-derived material that melts on your tongue in a breath strip, could also preserve pesticide-detecting enzymes. In order to test a glass of water, all a person would need to do is plop a pill in, watch it dissolve, and observe changes in color.
“If the water doesn’t have any pesticides, [the water] actually forms a very strong blue. If it’s transparent at the end, it’s very contaminated,” Filipe says. “In between, we have a cell phone app–you can take a cell phone picture of it. And that picture sends to a website with GPS coordinates.”
Water analysis can often be a slow, costly process. New solutions have ranged from tracking DNA markers in contaminated wells to an array of paper litmus tests. But one of the advantages of Filipe’s pill is that it’s extremely cheap to make–akin to making a tray of ice cubes, according to Filipe. For a dollar, he says, his students can produce a thousand pills a day.
Later this year, the student who made the breath strip connection, Sana Jahanshahi-Anbuhi, will launch a field test of the pills in Kerala, India. In the meantime, Filipe’s lab is exploring more applications. The researchers say that molecules detecting E. coli could be embedded in the pills, or maybe even vaccines. If they find a way to preserve vaccines without refrigeration, the pill could have a major impact on communities that lack access to fully equipped health care systems.