Synthesis and characterisation of a novel bi-nuclear copper2+ complex and its application as electrode-modifying agent for simultaneous voltammetric determination of dopamine and ascorbic acid
AbstractA new binuclear complex of copper2+, [LCu2+(CH3COO)2Cu2+L](CH3COO)2 where L is N,N-bis(phthalimide)ethylenediamine, was synthesised and characterised. The complex ion [LCu2+ (CH3COO)2Cu2+L]2+ was encapsulated into ZSM-5 zeolite and used to modify the surface of the glassy carbon electrode. This modified electrode, in a phosphate buffer solution at pH 7.0, exhibited an oxidation potential for dopamine (DA) and ascorbic acid (AA) at electrode potentials of 0.230 V and −0.090 V vs. Ag/AgCl respectively, a separation of 0.320 V. The electro-oxidation of DA or AA on the modified electrode is independent of each other. No interference was observed from Na+, K+, Cl−, SO42−, Mg2+, Ca2+, Zn2+, Fe2+, and glucose. The detection limits obtained were 2.91 × 10−7 M for DA and 3.5 × 10−7 M for AA.