ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Electroanalytical detection of heavy metals using metallophthalocyanine and silica-coated iron oxide composites

Denisha Gounden, Samson Khene, and Nolwazi Nombona

University of KwaZulu-Natal, Durban, South Africa

E-mail: nolwazi.nombona@up.ac.za

Abstract: The monitoring of heavy metal ions particularly in water is important in safeguarding the environment and humans from the toxic effects these metal ions pose. This work describes the synthesis, characterization and electrocatalytic properties of silica-coated iron oxide nanoparticles (Si-NP) in the presence of cobalt or iron phthalocyanines (MPc) for heavy metal (HM) detection. TEM, XRD, XPS and VSM confirmed the successful synthesis of Si-NP with an average diameter of 12.07 nm. The electrochemical sensing properties of MPc/Si-NP-modified glassy carbon electrodes (GCE) were assessed for HM detection. Differential pulse anodic stripping voltammetry (DPASV) studies indicated detection limits that compared positively with the literature. The FePc/Si-NP composite showed the lowest detection limits (S/N = 3) of 3.66, 11.56, 2.28, 4.54 μg L⁻¹ for arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb), respectively. A linear working range of 10–100 μg L⁻¹ was obtained for As³⁺, Hg²⁺ and Pb²⁺ ions while it was between 20 and 100 μg L⁻¹ for Cd²⁺ ions. Both composites displayed reproducible signals for the simultaneous detection of the HMs for ten consecutive scans. These composites offer a cheap and simplistic sensing device for HM analysis.

Keywords: Phthalocyanine ; Iron oxide ; Heavy metal detection 

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-018-0545-0

Chemical Papers 72 (12) 3043–3056 (2018)