Nanogold modified glassy carbon electrode for the electrochemical detection of arsenic in water

The application of gold nanoparticles (AuNPs) modified glassy carbon electrode in the electrochemical detection of arsenic is presented. AuNPs were electrodeposited onto the surface of a glassy carbon electrode (GCE) by cyclic voltammetry in a potential range of–400 to 1100 mV for 10 cycles. The modification of the GCE with AuNPs resulted in increased redox current of [Fe(CN)₆]^3–/4– when compared to that obtained from bare GCE. As(III) detection was carried out using square wave anodic stripping voltammetry (SWASV) at the following optimised conditions: pH 1, deposition potential of–600 mV and pre-concentration time of 60 s. The GCE–AuNPs electrode detected As(III) to the limit of 0.28 ppb and was not susceptible to many interfering cations except Cd, Cu and Hg. The GCE–AuNPs electrode was used for the quantitative analysis of arsenic in real water sample. The results obtained were in good correlation with those obtained from inductively coupled plasma—optical emission spectroscopy technique, thus validating the reported method.