Green modified electrode for sensitive simultaneous heavy metal ions electrodetection

Abstract

The detection of heavy metals (HM) is of particular importance in terms of human health and environmental protection. Electrochemical sensors are usually limited by the interference of various cations that coexist in real samples. These shortcomings are usually solved by incorporating various particles into the electrode material, which represents another source of pollution, thus being unsustainable. In this study, it was demonstrated that the new investigated natural clay (nc), used without processing, and immobilized with chitosan (Chi) matrix on the surface of a GCE in order to obtain nc-Chi/GCE modified electrode can detect, separately and simultaneously, four heavy metals (i.e. Zn 2+ , Cd 2+ , Pb 2+ and Cu 2+ ). The electrochemical behavior of the new eco-friendly modified electrode and its capacity to detect heavy metals has been investigated by electrochemical impedance spectroscopy (EIS) and square wave anodic stripping voltammetry (SWASV). The obtained electroanalytical performances (i.e., a detection limit of 43.1 nM for Zn 2+ , 19.1 nM for Cd 2+ , 4.3 nM for Pb 2+ and 57.3 nM for Cu 2+ ) corroborated with the reproducibility and stability of the modified electrode successfully recommends it as a suited device for heavy metals ions detection. The nc-Chi/GCE modified electrode was validated by measurements performed in real samples of tap water. • Natural clay immobilised with chitosan on the glassy carbon electrode surface. • The device was used for heavy metal ions detection (i.e. Zn 2+ , Cd 2+ , Pb 2+ and Cu 2+ ). • The performances were validated by measurements in real samples of tap water.