Determination of o-Aminophenol by Novel Co(II) Phthalocyanine with Appliance of Composite MWCNTs

A novel peripherally tetra naphthol substituted Co(II) phthalocyanine (NCoPc) was synthesized by the reaction of naphthol linked phthalonitrile, and cobalt chloride, in the presence of catalytic amount of DMF, DBU, and K₂CO₃. The NCoPc and its composite with MWCNTs were characterized by FTIR, NMR, UV–Vis, XRD, TGA, and mass spectroscopic techniques. The NCoPc and NCoPc-MWCNTs-coated glassy carbon electrodes (GCEs) were used to electrochemically detect and quantify ortho amino phenol (oAP) oAP in aqueous solutions. Cyclic voltammetric data established a linear response between the oAP oxidation current (ipa) and its molar concentration (10–190 μM). The limit of detection (LoD) of the two modified electrodes was comparable (1.5 μM and 25 nM, respectively). The NCoPc and NCoPc-MWCNTs-GCEs (in the concentration range of 10–160 μM) were both low and comparable. The LoD values for oAP at the NCoPc-GCE and NCoPc-MWCNTs by DPV were 1.2 µM and 42 nM and CA were 10 nM and 6.5 nM, respectively. They are exhibited good electrocatalytic activity towards the oxidation of oAP, and this was aided by the improved conductivity of the composite modifiers.

Graphical Abstract