Large interlayer spacing Nb 4 C 3 T x (MXene) promotes the ultrasensitive electrochemical detection of Pb 2+ on glassy carbon electrodes.

A Nb 4 C 3 T x (MXene)-modified glassy carbon electrode was used for the electrochemical detection of Pb 2+ ions in aqueous media. The sensing platform was evaluated by anodic stripping analysis after optimizing the influencing factors such as pH, deposition potential, and time. The large interlayer spacing, high c lattice parameter and higher conductivity of Nb 4 C 3 T x compared to other MXenes enhance the electrochemical detection of Pb 2+ . The developed sensor can reach a detection limit of 12 nM at a potential ∼-0.6 V. Additionally, the developed sensor showed promising selectivity in the presence of Cu 2+ and Cd 2+ , and stability for at least 5 cycles of continuous measurements with good repeatability. This work demonstrates the potential applications of Nb 4 C 3 T x towards the development of effective electrochemical sensors.