An electrochemical sensor based on phytic acid functionalized polypyrrole/graphene oxide nanocomposites for simultaneous determination of Cd(II) and Pb(II)

An electrochemical sensor was developed for detecting heavy metal ions by using a phytic acid functionalized polypyrrole (PPy)/graphene oxide (GO) modified electrode. PPy/GO nanocomposites were synthesized by in situ chemical oxidation polymerization. The PPy/GO nanocomposites were functionalized with phytic acid (PA) molecules by electrostatic attraction. The structural features of the fabricated nanocomposites were confirmed by transmission electron microscopy (TEM), attenuated total reflection infrared (ATR-IR) spectroscopy and Raman spectroscopy. The PA/PPy/GO modified electrode exhibited high electrochemical conductivity, and produced a remarkable increase in peak current compared with the PPy/GO and PA/GO modified electrodes. The developed sensor was used for the electrochemical analysis of various trace metal ions by differential pulse voltammetry (DPV). The modified electrode demonstrated to measure Cd(II) and Pb(II) with a linear working range of 5–150   μg/L. This work demonstrated a simple, rapid and high performing electrochemical strategy for high-sensitivity detection of heavy metal ions.