Sensitive and reliable electrochemical detection of nitrite and H2O2 embellish-CoPc coupled with appliance of composite MWCNTs

The electrocatalytic properties of tetra L-Methionine cobalt (II) phthalocyanine (CoTL-MethPc) and functionalized MWCNTs, decorated on glassy carbon electrode (GCE) was investigated. The synthesis of the CoTL-MethPc was confirmed using UV-Vis, FT-IR, XRD, TGA and MASS techniques. Successful modification of GCE with the CoTL-MethPc and their composite was also confirmed using cyclic voltammetry (CVs), differential pulse voltammetry (DPV) and chrono-amperometry (CA) techniques. CoTL-MethPc/MWCNTs/GCE was the best electrode towards nitrite and hydrogen peroxide (H2O2) detection with a very low detection limit (30 and 10 nmol L-1) by CVs method, which compared favorably with literature, good sensitivity, electrocatalytic oxidation of nitrite and hydrogen peroxide on CoTL-MethPc/MWCNTs/GCE electrode was diffusion controlled but characterized with some adsorption of electrooxidation-reduction reaction intermediates products. The fabricated sensors are easy to prepare, cost-effective and can be applied for real sample analysis of nitrite in beetroot vegetable. The excellent electrocatalytic property of CoTL-MethPc/MWCNTs is high reproducibility, repeatability, selectivity. (C) 2020 Elsevier B.V. All rights reserved.