Opitimization of effective chemical and instrumental parameters on the response of the electrochemical sensor, sensitive to ascorbic acid

A new method is developed for the catalytic oxidation of ascorbic acid at graphite zeolitemodifiedelectrode, doped with copper (II) (Cu2+A/ZME). Copper (II) exchanged in zeolite typea acts as catalyst to oxidize ascorbic acid. The modified electrode lowered the overpotential ofthe reaction by ∼-200 mV.First, the electrochemical behavior of copper (II), incorporated in the zeolite type A modifiedelectrode, was studied. The results illustrate that diffusion can control the copper (II) /copper (0)redox process at the GPE/Cu2+ /ZME. Then, the behavior of electrocatalytic oxidation reactionfor ascorbic acid was researched. The electrode was employed to study electrocatalytic oxidationof ascorbic acid, using cyclic voltammetry and chrono amperometry as diagnostic techniques. Alinear calibration graph was obtained over the ascorbic acid with a concentration range of 1-10and 40-500 nM. The detection limit (LOD) of ascorbic acid was estimated as 0.33nM.

Keywords:

Electrochemistry , Electroanalysis , Modified Electrodes , Sensors , Biomagnizers , Nanomaterials , Nanocomposites