Simultaneous detection of lead and cadmium based on N-doped MoS₂/MWCNTs nanocomposites

Heavy metal pollution in the environment has posed a serious threat to human health and ecosystems. Therefore, it is urgent to develop a fast and effective sensing method for detecting heavy metal ions (HMIs). A simple and rapid ultrasonic mixing method was used to prepare nanocomposites consisting of cysteine, multi-walled carbon nanotubes, and nitrogen-doped molybdenum disulfide (L-Cys/MWCNTs/N-MoS2). Fully combining the excellent features of 2D materials and carbon nanomaterials, the nanocomposites have been successfully used as sensor interface materials for the simultaneous detection of lead ions (Pb2+) and cadmium ions (Cd2+). The L-Cys/MWCNTs/N-MoS2@GCE sensor has a wide linear range for the detection of Pb2+ and Cd2+, with the detection limits as low as 0.67 nM and 5.3 nM, respectively. In addition, the sensor performs well in stability, reproducibility, and anti-interference performance. The L-Cys/MWCNTs/N-MoS2@GCE sensor can also be used for the detection of Pb2+ and Cd2+ in tap water and lake water with good recovery (> 90%), which may provide a promising strategy for the simultaneous in situ and sensitive detection of heavy metal ions in the aqueous environment.