Electrochemical real-time sensor for the detection of Pb(II) ions based on TiCT MXene.

Lead ions are especially harmful to human health, causing significant developmental and behavioral abnormalities even at small concentrations. In real-life samples, lead ions are present in mixtures with other metal ions, creating a challenge to detect it selectively at low quantities. To address these challenges, we prepared an electrochemical sensor based on delaminated TiCT MXene, which can selectively detect low concentrations of Pb in a solution containing other common metal ions. Cyclic voltammetry was applied as an electrochemical detection method. The proposed reaction mechanism involves a reversible transition between Pb ions and PbO at the MXene-based layer. The sensitivity of the sensor towards Pb ions and a limit of detection were determined. The sensor, as prepared, had a linear response range within 0.15-1.0 μM, with a sensitivity of 26.7 μA/μM and LOD value of 48.7 nM, which meets the requirements set by the World Health Organization.