Curcumin multi-wall carbon nanotubes modified glassy carbon electrode and its electrocatalytic activity towards oxidation of hydrazine

A CM-MWCNT-GCE modified electrode has been fabricated by electrodepositing curcumin (CM) at the surface of multi-wall carbon nanotubes (MWCNT) modified glassy carbon electrode (GCE). The CM-MWCNT-GCE shows a well-defined two-electron and two-proton redox couple with the formal potential of 0.14V (vs. SCE) that results from the electrochemical oxidation product of CM, a CM derivative in quinone form. It also shows good electrocatalytic activity towards the oxidation of hydrazine at a reduced overpotential as well as an increased peak current compared with those at a CM modified GCE, a MWCNT modified GCE or an activated GCE. The catalytic rate constant k(cat) is determined to be 6.26 x 10(3) M-1 s(-1) by chronoamperometry. The calibration curve for hydrazine determination is linear in the range of 2-44 mu M in pH 8.0 phosphate buffer by amperometry. The detection limit and the sensitivity are 1.4 mu M and 22.9 nA mu M-1, respectively. The modified electrode is simple in preparation, and is of character of fast response, high sensitivity and good reproducibility for hydrazine determination. (c) 2008 Elsevier B.V. All rights reserved.