A pocket-sized tester can now sniff out 'forever chemicals' in drinking water

PFAS — the long-lasting 'forever chemicals' found in water around the world — are normally checked by sending samples to a laboratory and waiting. Researchers at the Okinawa Institute of Science and Technology (OIST) in Japan have built a portable alternative, described in the journal Biosensors and Bioelectronics. Their sensor is coated with tailor-made plastic moulds — 'synthetic antibodies' — shaped to catch specific PFAS molecules; when the chemicals bind, an electrical current changes, revealing the concentration on the spot. In tests on fresh and drinking water, the readings closely matched the true amounts for PFOA and PFOS, the two most common PFAS chemicals, at the levels Japan regulates (50 picograms per millilitre). The prototype's 100 disposable electrodes were screen-printed onto fabric in a few hours and plug into a phone or laptop — cheap, quick checks where people actually drink the water.

SDG 6 · Clean water and sanitation — Mechanism: tech innovation