Determination of captopril in patient human urine using ferrocenemonocarboxylic acid modified carbon nanotubes paste electrode

In this work, we describe an new strategy for electrochemical determination of captopril (CA) using ferrocenemonocarboxylic acid as a mediator and multi wall carbon nanotubes as sensors in aqueous solution at pH=7.0. The diffusion coefficient (D), and the kinetic parameters such as electron transfer coefficient, (α) and heterogeneous rate constant, (kh) for CA were also determined using electrochemical approaches. Under the optimized conditions, the electrocatalytic oxidation peak current of captopril showed two linear dynamic ranges with a detection limit of 0.3×10-6 mol L-1 captopril. The linear calibration ranges was 0.8 × 10-6 ─ 65 × 10-6 mol L-1 using cyclic voltammetry. Finally, this modified electrode was also examined as a selective, simple and precise new electrochemical sensor for the determination of captopril in real samples such as drug and patient human urine.