Synthesis, structural characterization and electrochemical studies switching of MWCNT/novel tetradentate ligand forming metal complexes on PIGE modified electrode by using SWASV.

A novel sensor of a square wave anodic stripping voltammetric (SWASV) determination of Pb(II) and Cd(II) with a Multiwall carbon nanotube MWCNT/(Hbpabza) novel tetradentate carboxamide ligand modified electrode is reported. The ligand was synthesized and prepared by the condensation of 2-pyridinecarboxylicacid and 2-aminobenzylamine, with triphenylphosphite as the activator and tetrabutylammonium bromide as the reaction medium. The ligand was characterized by UV-Visible spectroscopy, Fourier transform infrared spectroscopy, Raman studies, Nuclear magnetic resonance spectroscopy and scanning electron microscope methods. The ligand was characterized voltammetrically using redox couples Fe(CN), complemented with electrochemical impedance spectroscopy (EIS). The modified electrode has provided an electrochemical sensing platform for simultaneous determination of Pb(II) and Cd(II) ions in 0.1 M acetate buffer solution (ABS) (pH 4.5) have been evaluated. The detection limit of MWCNT/(Hbpabza) modified electrode toward Pb(II) and Cd(II) is 2.7 nM and 0.92 nM, (S/N = 3) respectively. The electrochemical parameters that exert influence on deposition and stripping of metal ions, such as supporting electrolytes, pH value and deposition time, were carefully studied. Linear response from 8.3 nM to 115 nM for both Pb(II) and Cd(II) metal ions were achieved with the modified electrode. The modified electrode was also successfully applied to the analysis of Pb(II) and Cd(II) in real sample with good recovery, ranging from 98.7-100%.