Graphene/polyaniline nanocomposite as an electrochemical sensor for ultrasensitive detection of Pb(II)

Abstract

This work describes the development of an electrochemical sensor for the ultrasensitive detection of Pb(II) using a graphene/polyaniline (GN/PANI) nanocomposite electrode prepared by a reverse-phase suspension polymerization technique in the presence of polyvinylpyrrolidone (PVP). The obtained GN/PANI nanocomposite was characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. The electrochemical behavior of lead ions (Pb2+) was determined by cyclic voltammetry and differential pulse voltammetry. The GN/PANI nanocomposite showed evidence of increased surface area under SEM. The GN/PANI-modified electrode exhibited high electrochemical conductivity, producing a four-fold increase in peak current (vs. the unmodified electrode). The largest current response was obtained when the weight fraction of graphene was 0.49%. A linear working range of 1.0x10-9 to 1.0x10-4 M was established between current and Pb2+ 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/PANI nanocomposite as a promising electrochemical sensorfor the determination of Pb2+.