A sensitive electrochemical sensor based on 3D porous melamine-doped rGO/MXene composite aerogel for the detection of heavy metal ions in the environment.

Herein, we developed a unique screen-printed carbon electrode (SPCE) with three-dimensional melamine-doped graphene oxide/MXene composite aerogel (3D MGMA) modification, which is used for the simultaneous and sensitive detection of three metal ions (Zn2+, Cd2+, and Pb2+) in the environment. A self-assembly method was used to fabricate 3D MXene aerogels based on MXene, graphene oxide (GO), and melamine. Notably, the network-like 3D structure combining 2D MXene and rGO sheets can provide a high ratio of surface area and enriched functional clusters, which are beneficial for improving the electrical conductivity and promoting the uptake of heavy metal ions. In the linear range of 3-900 μg L-1, the constructed innovative sensing platform can sensitively detect Zn2+, Cd2+, and Pb2+ simultaneously, with detection limits of 0.48 μg L-1,0.45 μg L-1 and 0.29 μg L-1 respectively. This work reflects precision and reliability in the detection of three water samples (tap water, Minzhu lake and Yangtze River) and four cereal samples (sorghum, rice, wheat and corn), proposing a novel strategy for monitoring heavy metal ions in the natural environment.