Simultaneous detection of heavy metal ions in food samples using a hypersensitive electrochemical sensor based on...

Heavy metal ions (HMIs) pollution has become a significant food safety concern owing to rapid urbanization and industrialization. In this study, a hypersensitive electrochemical sensor based on amino-functionalized MXene and bimetallic atom MOFs nanocomposites (MXene-NH₂@CeFe-MOF-NH₂) was developed and applied for the detection of HMIs. MXene-NH₂@CeFe-MOF-NH₂ nanocomposites were obtained by incubating MXene@CeFe-MOF prepared by hydrothermal and self-assembly methods in APTES to endow them with a large amount of surface amine functional groups. The introduction of -NH₂ could lead to a coordination effect between the nanocomposites and HMIs, promoting the enrichment efficiency of HMIs on the surface of the working electrode. The sensing platform demonstrated excellent detection performance, with limit of detection (LOD) values of 0.69 nM, 0.95 nM, and 0.33 nM for Cd²⁺, Pb²⁺ and Hg²⁺, respectively, which were far below the maximum residue levels specified by the Chinese standards. Furthermore, the sensor was employed to analyze representative real samples (fish, whole milk, rice, and corn) to simulate an accurate analysis in complex scenarios and successfully detect the three HMIs simultaneously.