Voltammetric determination of carbidopa and folic acid using a modified carbon nanotubes paste electrode

Abstract

A novel electrochemical sensor for the selective and sensitive detection of carbidopa in presence of large excess of folic acid at physiological pH was developed by the bulk modification of carbon paste electrode (CPE) with carbon nanotubes (CNTs) and vinylferrocene. Large peak separation, good sensitivity and stability allow this modified electrode to analyze carbidopa individually and simultaneously along with folic acid. Applying square wave voltammetry (SWV), a linear dynamic range of 1.0?10-6- 7.0?10-4 M with detection limit of 2.0?10-7 M was obtained for carbidopa. Finally, the proposed method was applied to the determination of carbidopa and folic acid in urine sample.