Electrocatalytic determination of captopril using a carbon paste electrode modified with N-(ferrocenyl-methylidene)fluorene-2-amine and graphene/ZnO nanocomposite

A carbon paste electrode (CPE) was modified with N-(ferrocenyl-methylidene) fluorene-2-amine and graphene/ZnO nanocomposite. The electrooxidation of captopril (CAP) at the surface of the modified electrode was studied using electrochemical approaches. The electrochemical study of the modified electrode, as well as its efficiency for the electrocatalytic oxidation of captopril, is described. The electrode was used to study the electrocatalytic oxidation of captopril, by cyclic voltammetry (CV), chronoamperometry (CHA) and differential pulse voltammetry (DPV) as diagnostic techniques. It has been found that the oxidation of captopril at the surface of modified electrode occurs at a potential of about 340 mV less positive than that of an unmodified CPE. DPV of captopril at the electrochemical sensor exhibited two linear dynamic ranges (0.1-100.0 and 100.0-800.0 mu M) with a detection limit (3 sigma) of 0.05 mu M.