An electrochemical sensing of Pb2+ and Cu2+ using a covalent organic polymer and multi-walled carbon nanotubes modified glassy carbon electrode in food samples

The harmful effects of heavy metals on human health are a well- known topic. In this work, an electrochemical sensor based on glassy carbon electrode (GCE) modified with the multi-walled carbon nanotubes (MWCNTs) and an imine-linked covalent organic polymer (COP) was employed to detect Pb 2+ and Cu 2+ through differential pulse anodic stripping voltammetry (DPASV) method. The COP was synthesized via the reaction of terephthalaldehyde (TPA) with aminoclay (AC). The synergetic effect between MWCNTs and synthesized COP increase electrochemical activity. The introduced sensor had linear ranges as Pb 2+ : 0.001-1600 nM and Cu 2+ : 0.008-1600 nM and the detection limits (LODs) 0.0003 nM and 0.002 nM for Pb 2+ and Cu 2+ , respectively. Finally, the modified GCE was employed for determination Pb 2+ and Cu 2+ in different samples with acceptable outcomes including the recovery ranging from 98.4 to 102.8% and the relative standard deviation (RSD) was less than 2.8%. • Sensor was designed based on multi-walled carbon nanotubes (MWCNTs)/covalent organic polymer (COP). • Electrode based on MWCNTs-COP nanocomposite was employed to detect Pb 2+ and Cu 2+ . • Sensor has good selectivity to detect target ions in the presence of other ions. • Sensor performs well in terms of stability, repeatability, and reproducibility. • The modified electrode was employed to detect Pb 2+ and Cu 2+ in food samples