Square wave voltammetry determination of brucine at multiwall carbon nanotube-modified glassy carbon electrodes

In this article, the electrochemical behavior of brucine at the multiwall carbon nanotubes (MWNTs)-modified glassy carbon electrode (GCE) was studied by cyclic voltammetry (CV) and square wave voltammetry (SWV). The purified MWNTs dispersed in N,N-dimethylformamide (DMF) were characterized by transmission electron microscopy (TEM). A series of electrochemical parameters of brucine were calculated by chronoamperometry (CA) and chronocoulometry (CC). A better electrochemical response was observed at MWNTs-modified electrode than the other film-modified electrodes. Cyclic voltammetric curves showed an irreversible oxidative peak (E-pa1=937mV) and a pair of perfect well reversible peaks, Delta E-p2 = 13 mV (E-pa2 = 418 mV, E-pc2 = 405 mV). The second redox peak current of brucine increased linearly with the square root of scan rate in the low range, so it is a diffusion -controlled process, and the electrocatalytic process mechanism for the brucine was investigated. The SWV currents of brucine at the modified electrode increased linearly with its concentration in the range of 1.0 X 10(-6) to 1.0 X 10(-4) mol L-1, with a detection limit of 2.0 x 10(-7) mol L-1. The MWNTs-modified electrode can be used to determine brucine in practical samples with satisfactory results. The method is simple, quick, sensitive, and accurate.