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 0.14 V (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 kcat is determined to be 6.26 × 103 M−1 s−1 by chronoamperometry. The calibration curve for hydrazine determination is linear in the range of 2–44 μM in pH 8.0 phosphate buffer by amperometry. The detection limit and the sensitivity are 1.4 μM and 22.9 nA μM−1, respectively. The modified electrode is simple in preparation, and is of character of fast response, high sensitivity and good reproducibility for hydrazine determination.