Abstract
Diphenylamine (DPA) monomers have been electropolymerized on the amino-functionalized multiwalled carbon nanotube (AFCNT) composite film modified glassy carbon electrode (GCE) by cyclic voltammetry (CV). The surface morphology of PDPA-AFCNT was studied using field-emission scanning electron microscopy (FE-SEM). The interfacial electron transfer phenomenon at the modified electrode was studied using electrochemical impedance spectroscopy (EIS). The PDPA-AFCNT/GCE represented a multifunctional sensor and showed good electrocatalytic behavior towards the oxidation of catechol and the reduction of hydrogen peroxide. Rotating-disk electrode technique was applied to detect catechol with a sensitivity of 1360 mu AmM-1 cm(-2) and a detection limit of 0.01mM. Amperometric determination of hydrogen peroxide at the PDPA-AFCNT film modified electrode results in a linear range from 10 to 800 mu M, a sensitivity of 487.1 mu AmM-1 cm(-2) and detection limit of 1 mu M. These results show that the nano-composite film modified electrode can be utilized to develop a multifunctional sensor.