Electrochemical real-time sensor for the detection of Pb(II) ions based on Ti₃C₂T_x 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 Ti₃C₂T_x MXene, which can selectively detect low concentrations of Pb²⁺ 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 Pb²⁺ ions and PbO at the MXene-based layer. The sensitivity of the sensor towards Pb²⁺ 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.