Enhanced Electrocatalytic Reduction of Oxadiargyl and Its Determination on 2-(4-((4-Acetylphenyl)diazenyl)phenylamino)-ethanol Modified Graphene-Paste Electrode

The electrochemical behavior of oxadiargyl at a graphene-paste electrode modified with an azo dye, 2-(4-((4-acetylphenyl)diazenyl)phenylamino)ethanol (ADPE), ADPE/MGRPE was investigated. The modified electrode showed high electrocatalytic activity toward oxadiargyl. The apparent electron transfer rate constant (ks) and charge transfer coefficient (a) between electrode and ADPE were 1.16 s-1 and 0.41, respectively. The differential pulse voltammetry response of the modified graphene-paste electrode was linear against the concentration of oxadiargyl in the range from 0.03 to 1.4 mg?L-1. The limit of detection was found to be 1.3 mu g?L-1 (S/N=3). The practical analytical utility of this electrode was demonstrated by measurement of oxadiargyl in river water, soil and rice samples.