A novel electrochemical sensor for simultaneous detection of Cd and Pb by MXene aerogel-CuO/carbon cloth flexible electrode based on oxygen vacancy and bismuth film.

Herein, a novel MXene aerogel-CuO/carbon cloth (MXA-CuO/CC) electrochemical sensor was constructed, and the synergistic adsorption of heavy metal ions by oxygen vacancies and Bi (III) was investigated with Cd and Pb as detection targets. The oxygen vacancies of CuO have a strong affinity for heavy metal ions, which promoted the adsorption of Cd and Pb on the electrode surface. In addition, the introduced Bi (III) can form alloys with heavy metal ions, which effectively enhanced the adsorption capacity of sensing electrodes for Cd and Pb. Differential pulse anodic stripping voltammetry (DPASV) was used to study the performance of MXA-CuO/CC sensitive electrode for the detection of Cd and Pb separately and simultaneously. The constructed sensing electrode has excellent detection performance, and can detect Cd (4 μg L- 800 μg L) and Pb (4 μg L- 1200 μg L) simultaneously with detection limits of 0.3 μg L (Cd) and 0.2 μg L (Pb), respectively. The proposed sensor electrode also has good anti-interference performance, excellent stability and reproducibility. It is worth mentioning that the proposed method can accurately detect Cd and Pb in food and water samples, which is consistent with the detection results of inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectroscopy (AAS).