Nanostructured Base Electrochemical Sensor for Determination of Sulfite

摘要

A novel carbon paste electrode modified with carbon nanotube and benzoylferrocene (BF) wasfabricated. The electrochemical study of the modified electrode, as well as its efficiency forelectrocatalytic oxidation of sulfite is described. Cyclic voltammetry was used to investigate the redoxproperties of this modified electrode. The electrode was also employed to study the electrocatalyticoxidation of sulfite, using cyclic voltammetry, chronoamperometry and square wave voltammetry asdiagnostic techniques. It has been found that the oxidation of sulfite at the surface of modifiedelectrode occurs at a potential of about 240 mV less positive than that of an unmodified CPE. Thediffusion coefficient, electron transfer coefficient, and heterogeneous rate constant, for oxidation ofsulfite at the modified electrode surface were also determined. Square wave voltammetry exhibits a-7 linear dynamic range from 1.010 to 4.010 M and a detection limit of 90.0 nM for sulfite. Finallythis modified electrode was used for determination of sulfite in real samples.