Electrochemical Syntheses and Characterization of Some Polydyes and their Application for the Simultaneous Determination of Ascorbic Acid and Uric Acid

Abstract

Abstract The electropolymerization and characterization of the monomers: gentian violet (GV), brilliant green (BG), aniline, and methyl violet (MV) and their copolymers were done using cyclic voltammetry (CV) on glassy carbon electrode (GCE) as a working electrode against Ag/AgCl reference electrode and platinum wire as counter electrode. The copolymers showed higher current peaks than their corresponding homopolymers. The electrochemical characterization of these polymers and copolymers was studied by scan rate effect each between 10 and 300 mV/s and pH effect between 1.56 and 5.30. After being modified by the copolymers: poly(BG-GV) and poly(BG-MV), the modified GCE showed good results in resolving the peaks of ascorbic acid and uric acid which otherwise showed one broad peak on bare GCE. The determination of the area of the modified electrode was done with all polymers investigated and also their copolymers. The CV in bare GCE was scanned at different scan rates of 4 mM K3[Fe(CN)6] in 1 M KNO3 solution. The square root of scan rate dependence of peak current was plotted and the Randles-Sevcik equation was applied to determine the diffusion coefficient of Fe(CN)63− ion and which was 1.13 x 10− 14 cm2/s. This was used to determine the area after running the CV of 4 mM K3[Fe(CN)6] in 1 M KNO3 at different scan rates. From the plot of peak current vs. square root of scan rate, the slope was determined and used to determine the area of the modified electrode from the Randles-Sevcik equation.