Sensitive electrochemical detection of arsenic (III) using gold nanoparticle modified carbon nanotubes via anodic stripping voltammetry.

Gold nanoparticles were deposited electrolessly on multiwalled carbon nanotubes (CNTs) via in situ reduction of HAuCl(4) by NaBH(4). 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 3 sigma) of 0.1 microgL(-1) was obtained but more importantly a sensitivity of 1985 microA microM(-1) was obtained with square wave voltammetry (SWV) in an optimised system with a deposition time of 120s. These values, particularly the high sensitivity compare favourably with previously reported methods in the area of electrochemical arsenic detection.