An Electrochemical Sensor Based on Graphene-Polypyrrole Nanocomposite for the Specific Detection of Pb (II)

An electrochemical sensor for the rapid, selective and sensitive detection of Pb2+ was developed using polypyrrole-graphene (PPY-rGO) nanocomposite by electrochemical synthesis. The PPY-rGO- modified electrode possessed a large effective area because of unique 3D porous architectures, and it displayed excellent selectivity for the determination of Pb2+. The response of Pb2+ on the nanocomposite-modified electrode was evaluated, and the relevant parameters were optimized by square wave anodic stripping voltammetry (SWASV). The stripping response was highly linear (R-2 = 0: 987) over a Pb2+ concentration range of 5 x 10(-9) mol/L to 7.5 x 10(-7) mol/L, with a detection limit of 4.7 x 10(-11) mol/L (3 sigma method). Furthermore, its applicability was validated for the determination of Pb2+ levels using spiked tap water at different concentrations. The polyporous structure, satisfactory reproducibility, long-term stability and simple synthesis endow the PPY-rGO nanocomposite a promising application in the determination of Pb2+.