Electrochemical sensor based on Bi/Bi2O3 doped porous carbon composite derived from Bi-MOFs for Pb2+ sensitive detection

It is of great significance to develop electrochemical sensors based on novel functional nanomaterials for heavy metal ions detection. In this work, a novel Bi/Bi2O3 co-doped porous carbon composite (Bi/Bi2O3@C) was prepared by simple carbonization of bismuth-based metal-organic frameworks (Bi-MOFs). The micromorphology, internal structure, crystal and elemental composition, specific surface area and porous structure of the composite were characterized by SEM, TEM, XRD, XPS, and BET. Further, a sensitive electrochemical sensor for Pb2+ detection was constructed by modifying Bi/Bi2O3@C on the surface of the glassy carbon electrode (GCE) based on the square wave anodic stripping voltammetric (SWASV). The different factors affecting the analytical performance were optimized systematically, such as material modification concentration, deposition time, deposition potential, and pH value. Under optimized conditions, the proposed sensor exhibited a wide linear range from 37.5 nM to 2.0 μM with a low detection limit of 6.3 nM. Meanwhile, the proposed sensor showed good stability, acceptable reproducibility, and satisfactory selectivity. The reliability of the as-proposed sensor was confirmed by the ICP-MS method for Pb2+ detection in different samples.