A simple and sensitive electrochemical sensing based on amine-functionalized metal–organic framework and polypyrrole composite for detection of lead ions in meat samples

The effective detection of trace lead ions in food is a challenging task due to its stability, difficulty in elimination, and high toxicity to the human health. Therefore, an electrochemical sensing based on an amine-functionalized Zr (IV) metal–organic framework (UiO-66-NH₂) and polypyrrole (PPy) composite nanomaterials were established for detected lead ions in meat. The UiO-66-NH₂@PPy composite nanomaterials were prepared by in-situ polymerization of reaction pyrrole on the surface of UiO-66-NH₂. The porous structure, high specific surface area of UiO-66-NH₂ and amino groups as metal ion binding sites are conducive to the adsorption and preconcentration of lead ions. The addition of PPy can enhance the conductivity of the composite and the active area of the electrode. Under optimal experiment conditions, the electrochemical sensing can be successfully used for the detection of trace lead ions, and the detection limit is as low as 0.05 μg/L. In addition, the sensing was applied to analyze lead ions in 30 pork samples, and the results showed that the lead contents in pork kidney samples were significantly higher than that in pork liver and pork tenderloin.