Highly efficient detection of Pb(II) ion in water by polypyrrole and metal-organic frame modify glassy carbon electrode

Since lead is teratogenic, carcinogenic and mutagenic, people pay increasing attention to lead contamination in water environment. In this work, a novel electrochemical sensor was developed to detect Pb(II) ion in water by PPy, MOFs and bismuth film (BF) modify GCE. Scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, electrochemical impedance spectroscopy, contact angleanalyses, cyclic voltammetry and differential pulse anodic stripping voltammetry were used to characterize the BF-PPy/UIO-66-NH2/GCE surface, revealing the physical and electrochemical properties of the electrode. MOFs increased the specific surface area and adsorption site of the electrode. The PPy enhanced the conductivity of the composites materials. MOFs and PPy synergistically promoted the electrochemical performance of the electrode. The deposition potential, deposition time, solution pH and Bi (III) concentration were optimized to determine the optimal detection condition. The electrode has a wide linear range (0.5 to 10 μg/L) with a low detection limit (0.05 μg/L). This electrode also has good anti-interference, repeatability and stability. Besides, it has been successfully applied to the detection of actual water samples. The recovery rates ranged from 95.4 % to 102.8 % with a relative standard deviation (RSD) less than 4.40 %. Our results provide an insight on efficient and rapid detection of Pb(II) ions in water environment in the future.