Decorated CoPc with appliance of MWCNTs on GCE: Sensitive and reliable electrochemical investigation of heavy metals

[Display omitted] •The synthesized CoTEIndCAPc was confirmed by physico-electrochemical analysis, thermal stable and good yield.•The CoTEIndCAPc with composite MWCNTs on modify GCE; nanomolar concentration detections for Pb(II) and Cd(II).•The CoTEIndCAPc/MWCNTs/GC electrode was low detection limit, high selectivity and sensitivity.•Simultaneous determination of Cd and Pb in real samples was studied. Theelectrocatalyticproperty of Tetra–ethyl-1H-indazol-3-carboxamide Cobalt (II) Phthalocyanine (CoTEIndCAPc) with MWCNTs, decorated on glassy carbon electrode (GCE) was investigated. The synthesis of theCoTEIndCAPc was confirmedby various spectroscopic techniques. Successfulmodificationof GCE with theCoTEIndCAPc and their composite was also confirmed using cyclicvoltammetry(CVs), differential pulse voltammetry (DPV) and chrono-amperometry (CA) techniques. CoTEIndCAPc/MWCNTs/GC electrode was the best electrode towards Cd2+ and Pb2+ detection with a very low detection limit (10 and 9 nmolL−1) by CVs method, which compared favorably with literature, good sensitivity, electrocatalytic oxidation of Cd2+ and Pb2+ on CoTEIndCAPc/MWCNTs/GC electrode was diffusion controlled but characterized with some adsorption of electro-oxidation reaction intermediates products. The fabricated sensors are easy to prepare,cost-effectiveandcan beapplied for real sample analysis of Cd2+ and Pb2+ in river water. The excellent electrocatalytic property of CoTEIndCAPc/MWCNTs/GC electrode is highreproducibility, repeatability and selectivity.