Electrochemical Behavior and Voltammetric Determination of Sulfaguanidine at a Glassy Carbon Electrode Modified With a Multi-Walled Carbon Nanotube

The electrochemical properties of sulfaguanidine (Sg) is investigated in detail at a glassy carbon electrode (GCE) modified with a multi-walled carbon nanotube (MWCNT). Cyclic voltammetry and chronoamperometry were used as diagnostic techniques. The MWCNT-GCE exhibited excellent electrocatalytic behavior for the oxidation of Sg as evidenced by the enhancement of the 2e-oxidation peak current and the shift in the oxidation potential to less positive values (by 90 mV) in comparison with a bare GCE. A detailed analysis of cyclic voltammograms and chronoamprograms gave fundamental electrochemical parameters including the electroactive surface coverage (Gamma), the transfer coefficient (alpha), the heterogeneous rate constant (k(s)) and the diffusion coefficient (D). Under the selected conditions, the peak current shows two dynamic linear ranges 10-100 mu M and 100-1000 mu M with the detection limit of 10 mu M. The method was successfully applied to analyze Sg in urine and serum samples.