Voltammetric distinction between dopamine and ascorbic acid using bare platinum disc electrode catalysed by bisethylenediaminecopper(II)

Abstract

Bare platinum disc electrode in presence of bisethylenediaminecopper(II), [Cu(en)₂]²⁺ where en = H₂NCH₂CH₂NH₂, in the electrolytic medium excellently distinguishes between dopamine (DA) and ascorbic acid (AA) in their aqueous mixture by cyclic voltammetry and square wave voltammetry. Both DA and AA independently changes the irreversible cyclic voltammogram of [Cu(en)₂]²⁺ into a quasi reversible ones with redox potential value +0.045 V and +0.150 V respectively. The redox currents are linear function of DA and AA concentration. Interaction of [Cu(en)₂]²⁺ with DA and AA mixture resulted quasi reversible cyclic voltammogram with a pair of redox couples with potential +0.220 V and +0.530 V due to DA and AA respectively.