Scientists have solved the problem of cumbersome, painfully slow water-testing by putting the potentially life-saving technology into a tiny pill.
The team at McMaster University has reduced the sophisticated chemistry required for testing water safety to a simple pill, by adapting technology found in a dissolving breath strip.
Instead of shipping water to the lab, they have created a way to take the lab to the water, putting potentially life-saving technology into the hands of everyday people.
The development has the potential to dramatically boost access to quick and affordable testing around the world.
"We got the inspiration from the supermarket," said Carlos Filipe, who worked on the project.
The idea occurred to Sana Jahanshahi-Anbuhi, a PhD student in Chemical Engineering who came across the breath strips while shopping and realised the same material used in the dissolving strips could have broader applications.
The technology is expected to have significant public health applications for testing water in remote areas and developing countries that lack testing infrastructure.
The researchers have now created a way to store precisely measured amounts of enzymes and other active agents in pills made from the same naturally occurring substance used in breath strips, putting lab-quality science within instant and easy reach of people who need quick answers to questions such as whether their water is safe.
"This is regular chemistry that we know works but is now in pill form," said John Brennan, director of McMaster's Bio-interfaces Institute, where the work took place.
"The user can be anybody in a village somewhere who can take a pill out of a bottle and drop it in water," said Brennan.
The material, called pullulan, forms a solid when dry, and protects sensitive agents from oxygen and temperature changes that can render them useless within hours.
Until now, such agents have had to be stored at extremely cold temperatures and shipped in vials packed in huge chunks of dry ice, at great cost and inconvenience. Using them has been awkward, bulky and often wasteful.
The new method, published in the European chemistry journal Angewandte Chemie, also holds promise for other applications, such as packaging that could change colour if food is spoiled.
The new method allows the same materials to be stored virtually anywhere for months inside tiny pills that dissolve readily in liquid.
The pills are inexpensive to produce and anyone can add them to well water, for an instant reading of pesticides, bacteria or metals, for example.