Simultaneous and sensitive detection of ascorbic acid in presence of dopamine using MWCNTs-decorated cobalt (II) phthalocyanine modified GCE

The synthesis of tetra8[(E)(4methoxybenzylidene)amino] naphthalene1amine cobalt (II) phthalocyanine (CoTMBANAPc) from cobalt (II) tetracarboxylic acid phthalocyanine (CoTCAPc) via amide bridge has been described for the first time. These macromolecules displayed admirable solubility in aprotic organic solvents and compound has been characterized by UV-Vis, FT-IR, H-1 NMR, XRD, TGA and Mass spectroscopic methods in addition to elemental analysis. The CoTMBANAPc was found to be electrochemically active and was immobilized on the GCE by decorating with MWCNT. The modified electrode was used for the simultaneous detection of two important biomolecules: Ascorbic acid (AA) and Dopamine (DA) by cyclic voltammetry, differential pulse voltammetry and amperometry methods. AA and DA exhibited two different and well-resolved cathodic peaks on the GCE/MWCNT-CoTMBANAPc electrode. The linear response was observed in the concentration range of 7.5 to 70 nM with detection limit of 6.6 mu M and 0. 33 nM for AA and DA, respectively on the modified electrode. The modified electrode is highly stable, sensitive and reproducible for the micromolar detection of AA and DA.