Amperometric hydrazine sensor using a glassy carbon electrode modified with gold nanoparticle-decorated multiwalled carbon nanotubes

Gold nanoparticles (AuNP) were deposited on the surface of multiwalled carbon nanotubes (MWCNT) by in-situ thermal decomposition of gold acetate under solvent and reducing agent free conditions to obtain a nanohybrid of AuNP-MWCNT. A glassy carbon electrode (GCE) was then modified with the nanohybrid and used for amperometric determination of hydrazine. The modified GCE showed an improved electrocatalytic effect towards hydrazine oxidation at a working potential of about 0.30 V (vs Ag|AgCl, KClsat). The calibration plot for hydrazine is linear in two concentration ranges, viz. from 0.1-100 mu M and 0.2-1 mM. The respective sensitivities are 4.98 and 4.00 mu A mu M(-1)cm(-2), and the limit of detection (at S/N = 3) is about 30 nM.