Detection of Nanomolar Concentrations H₂O₂ Using Cobalt (II) Phthalocyanine Modified GCE with MWCNTs

Abstract

The synthesis of tetra 4-(3-tert-butyl-4-methoxyphenoxy) benzene cobalt (II) phthalocyanine (CoTTBMPPc) from cobalt (II) tetracarboxylic acid phthalocyanine (CoTCAPc) via Oxygen Bridge. These macromolecules displayed admirable solubility in aprotic organic solvents and were characterized by UV-Vis, FT-IR, ¹H NMR, XRD, TGA, mass and elemental analysis. The CoTTBMPPc was found to be electrochemically active and was immobilized on the GCE with composite MWCNTs. The modified electrode was used for the Hydrogen Peroxide (H₂O₂) detection by cyclic voltammetry, differential pulse voltammetry, and amperometry methods. H₂O₂ exhibits cathodic peak potential on the GCE/MWCNTs/CoTTBMPPc electrode. The linear response was observed in the concentration range (10 to 100 for CV of, 10-150 for DPV and 10-200 nM in amperometry), detection limit (5.33 in CV, 6 in DPV and of 4 nmol L^-1 in amperometry) with limit of quantification (16 for CV, 18 for DPV and up to 12 nmol L^-1 in amperometry), respectively on the modified electrode. The modified electrode is stable, sensitive, selective and reproducible for the nanomolar detection of H₂O₂ in neutral PBS electrolyte solution.

GRAPHICAL ABSTRACT

Key words:

• H₂O₂
• CoPc
• Nanomolar
• CV
• DPV
• CA