Poly‐(Alizarin Red S)‐Modified Glassy Carbon Electrode for Simultaneous Electrochemical Determination of Levodopa, Homovanillic Acid and Ascorbic Acid

Abstract A polymeric film of Alizarin Red S was formed on a glassy carbon electrode and used for electrochemical detection of Levodopa ( L ‐DOPA) and homovanillic acid (HVA) in the presence of ascorbic acid (AA). The sensor represented excellent electrocatalytic activity for their oxidations. The resultant differential pulse voltammograms show well defined and fully resolved anodic oxidation peaks for determination of the analytes. Anodic oxidation currents of L ‐DOPA, HVA, and AA showed linearity with good correlation coefficient (>0.996), high sensitivity, and low detection limits (6, 17, and 30 nM respectively). The sensor was used for recovery of analytes in human plasma samples.