Abstract
Gold nanoparticles were deposited electrolessly on multiwalled carbon nanotubes (CNTs) via in situ reduction of HAuCl4 by NaBH4. The resulting gold covered nanotubes were immobilised onto the surface of a glassy carbon electrode via evaporation of a suspension in chloroform. Anodic stripping voltammetry was performed with the modified electrode in As(III) solutions. A limit of detection (LOD based on 3σ) of 0.1 μg L−1 was obtained but more importantly a sensitivity of 1985 μA μM−1 was obtained with square wave voltammetry (SWV) in an optimised system with a deposition time of 120 s. These values, particularly the high sensitivity compare favourably with previously reported methods in the area of electrochemical arsenic detection.