V₂CTₓ MXene modified electrode for simultaneous detection of cadmium and lead ions

The detection of toxic heavy metal ions (e.g., Cd 2+ , Pb 2+ ) in water is essential for public health and environmental monitoring. Herein, we describe the fabrication of a V₂CTₓ MXene-based electrochemical sensor on a glassy carbon electrode (GCE) for the highly sensitive detection of Cd 2+ and Pb 2+ in water. V 2 CT x was synthesized by selective etching and characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) for its morphology and composition. The results revealed that the V 2 CT x possesses a typical two-dimensional layered structure with abundant surface functional groups, thus providing active sites conducive to the adsorption and electron transfer of heavy metal ions. Cyclic voltammetry (CV) demonstrated a significant enhancement in electrochemical activity upon V₂CTₓ modification. Using the optimized conditions (V 2 CT x concentration of 1 mg/mL, pH 4.0, deposition voltage of −1.3 V, deposition time of 6 min), the detection of Cd 2+ and Pb 2+ were performed by square wave anodic stripping voltammetry (SWASV). The limits of detection for Cd 2+ and Pb 2+ were 2.28 μg/L and 2.40 μg/L, respectively, which to meet national drinking water standards. The V₂CTₓ/GCE showed good repeatability, reproducibility, anti-interference ability. The V 2 CT x /GCE holds great potential in the detection of heavy metal ions in real water samples.