Graphene/Polyaniline Nanocomposite as an Electrochemical Sensor for Ultrasensitive Detection of Pb(II)

摘要

This work describes the development of an electrochemical sensor for the ultrasensitive detection ofPb(II) using a graphene/polyaniline (GN/PANI) nanocomposite electrode prepared by a reverse-phase suspension polymerization technique in the presence of polyvinylpyrrolidone (PVP). Theobtained GN/PANI nanocomposite was characterized by scanning electron microscopy (SEM) andFourier transform infrared (FT-IR) spectroscopy. The electrochemical behavior of lead ions (Pb 2+ ) wasdetermined by cyclic voltammetry and differential pulse voltammetry. The GN/PANI nanocompositeshowed evidence of increased surface area under SEM. The GN/PANI-modified electrode exhibitedhigh electrochemical conductivity, producing a four-fold increase in peak current (vs. the unmodifiedelectrode). The largest current response was obtained when the weight fraction of graphene was 0.49%.A linear working range of 1.0×10 -9 to 1.0×10 -4 M was established between current and Pb 2+concentration with detection limits (S/N = 3) of 0.06088 nM. The large specific surface area,satisfactory repeatability, long-term stability and simple synthesis promote the GN/PANInanocomposite as a promising electrochemical sensorfor the determination of Pb 2+ .