Voltammetric sensing of Pb(II) in wastewater using gold– poly (propylene imine) dendrimer electrodeposited on expanded graphite

A simple experimental approach for the electroanalytical quantification of Pb(II) employing gold-poly (propylene imine) dendrimer as the nanomediator was developed using exfoliated graphite electrode. The sensor was produced by co-electrodeposition of generation 3 poly (propylene imine) dendrimer and gold nanoparticles on exfoliated graphite, which was synthesised through graphite intercalation and exfoliation. Using cyclic voltammetry and electrochemical impedance spectroscopy, the electrochemical properties of modified and unmodified exfoliated graphite electrodes were investigated in [Fe(CN)6] 3-/4- solution, the electrodeposited gold-poly (propylene imine) dendrimer expanded graphite sensor showed an increase in electroactive surface area and faradaic current compared to the unmodified expanded graphite electrode. The optimisation parameters chosen for this investigation are 0.1 M H2SO4 as the supporting electrolyte, a pre-concentration period of 210 s, a deposition potential of -0.6 V and pH 1. A linear regression of Y(A) = 1.340X + 209.44 was achieved, with a limit of detection of 0.15 ppb. More specifically, the three cations that interfered with the analysis of the Pb(II) ion were Cd(II), Hg(II), and Cu(II). The sensor was used to quantify Pb(II) ion in real water analysis, and the results were validated using inductively coupled plasmaoptical emission spectroscopy (ICP-OES).