Editors: | F. Kongoli, H. Inufasa, M. G. Boutelle , R. Compton, J.-M. Dubois, F. Murad |
Publisher: | Flogen Star OUTREACH |
Publication Year: | 2018 |
Pages: | 216 pages |
ISBN: | 978-1-987820-84-3 |
ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
In South Africa, industrial development and mining sustains the country's economy. Unfortunately, the effluents from these industries introduce heavy metal pollutants such as lead into the environmental water. Lead(II) is widely recognized as a highly toxic and non-biodegradable metal [1,2,3]. This study addresses a method of monitoring lead(II) by modifying glassy carbon electrode (GCE) with gold nanoparticles (AuNPs) and generation 2 (G2) poly(propyleneimine) dendrimer (PPI), to provide a highly sensitive electrochemical sensor for the determination of lead(II) ions in water using square wave anodic stripping voltammetry (SWASV). The co-deposition of PPI and AuNPs on the surface of GCE was confirmed by field emission scanning microscopy (FESEM). Voltammetric probing showed that the GCE/PPI-AuNP platform exhibited reversible electrochemistry and conductivity in [Fe(CN)6]<sup>3-/4-</sup> redox probe. The electroactive surface area of the modified electrodes were also calculated in order to illustrate that the prepared PPI+AuNP nanocomposite could improve the surface area and conductivity of the GCE and was found to be 8.17 mm<sup>2</sup>, GCE-AuNP, 10.84 mm<sup>2</sup>, GCE-PPI, 11.03 mm<sup>2</sup>, while 11.13 mm<sup>2</sup> was found for GCE-PPI+AuNP. The electroactive surface area of GCE-PPI+AuNP modified electrode increased to approximately 36.23% as compared to bare GCE, which provided an effective evidence for the superior conductivity of PPI+AuNP as expected. The effect of different electrochemical parameters on the sensitivity of the sensor for the Pb2+ detection were also scrutinized, including supporting electrolyte (HNO<sub>3</sub>), pH (1), deposition potential (-0.8 V) and deposition time (150s). The sensor was applied in the detection of lead(II) in real water sample and it was exhibited good stability and the results were validated by ICPOES.