A research team has developed a fluorescent probe that changes from red to green as it detects uranyl ions, a form of uranium that can contaminate water. Made from europium, zinc and an organic ligand, the probe measured uranyl concentrations down to 51 nanomolar in laboratory tests. A smartphone camera could also read the color change, suggesting a route toward portable water monitoring where laboratory instruments are unavailable. Tests with lake water and seawater showed promising accuracy, although broader testing in complex environmental samples is still needed.
