Water-testing pills draw on breath-freshening tech
Wondering if it's safe to drink the water from your remote village's well? Typically, the only way of finding out involves sending a sample of that water off to a lab, or using testing agents that must be shipped in and kept on dry ice. Now, however, scientists from Canada's McMaster University have developed simple pills that can do the job – and they were inspired by breath-freshening strips.
PhD student Sana Jahanshahi-Anbuhi, who is one of the team members, first came up with the idea when he saw some of the strips while grocery shopping. Breath strips are made with an edible polymer called pullulan, that forms a protective solid shell when dry, but that dissolves when exposed to liquid.
He surmised that pullulan could also be used to protect the agents used to test water for pathogens. Those agents can deteriorate within hours of exposure to oxygen and temperature changes, which is why they must ordinarily be shipped and stored sealed in vials, and at low temperatures.
As it turns out, Jahanshahi-Anbuhi was onto something. The resulting pills are cheap to produce, can be kept at room temperature for months at a time, and are simply added to a sample of the local water when testing is required. If the sample changes color after being shaken, it means that the water contains harmful bacteria, pesticides, heavy metals, or other pollutants.
While the pills could be useful to people such as hikers, they should be particularly helpful to people in developing nations, that lack easy access to decently-equipped labs. It is also hoped that the technology could be applied to things like food packaging that changes color if the contents are spoiled.
A paper on the research was recently published in the journal Angewandte Chemie.
Source: McMaster University