Researchers demonstrate smartphone measurement of mercury with molecular sensor

Istanbul Technical University researchers demonstrated a molecular sensor that lets a smartphone measure mercury(II) ions through a color change. In controlled experiments, the smartphone method detected concentrations from 1.66 × 10⁻⁹ to 7.50 × 10⁻⁶ M, with its lower detection limit below the U.S. drinking-water threshold for inorganic mercury. Mercury opens a selenium-based molecular structure, changing the solution from yellow to green and producing near-infrared light. Researchers photographed samples with a Redmi Note 10S and compared red and green color components to measure concentrations. The work, published in Talanta, required sample preparation and controlled lighting. Most experiments used samples deliberately spiked with mercury; naturally contaminated samples and field systems still require testing.