Sharif Digital Repository

Nickel-modified glassy carbon electrode (GC/Ni) prepared by galvanostatic deposition was used for the electrocatalytic oxidation of glucose in alkaline solutions where different electrochemical methods were employed. In cyclic voltammetry studies, in the presence of glucose an increase in the peak current of the oxidation of nickel hydroxide is followed by a decrease in the corresponding cathodic current. This suggests that the oxidation of glucose is being catalyzed through mediated electron transfer across the nickel hydroxide layer comprising nickel ions of various valence states. Under the chronoamperometric regime, the reaction followed a Cottrellian behavior and the diffusion... 

A carbon paste electrode, modified with 2, 2″-[1,7- hepthandiylbis(nitriloethylidyne)]-bis-hydroquinone and TiO 2 nanoparticles, was used for the simultaneous determination of dopamine (DA), uric acid (UA), and l-cysteine. The study was carried out by using cyclic voltammetry, chronoamperometry, and square wave voltammetry (SWV) techniques. Some kinetic parameters such as the electron transfer coefficient (α) and heterogeneous rate constant (k s) were also determined for the DA oxidation. A dynamic range of 8.0-1400 μM, with the detection limit of 8.4∈×∈10 -7 M for DA, was obtained using SWV (pH∈=∈7.0). The prepared electrode was successfully applied for the determination of DA, UA, and...