Ultra-Traces Detection by Gold-Based Electrodes in As(III) Novel Photoremediation

The aim of this manuscript is to develop a combined method for the detection and remediation of As(III) species in aqueous environment. Linear sweep adsorptive stripping voltammetric technique, based on the use of commercially available gold nanoparticle-modified screen-printed electrodes is proposed to detect ultra traces of As(III) in solution. The choice of inexpensive and disposable electrodes permits to eliminate undesirable fouling processes, usually occurring in this kind of electroanalytical methods. The achieved limit of detection, one order of magnitude lower than the World Health Organization tolerance level (10 ppb), allows to monitor the trend of the photocatalytic oxidation of arsenite to less noxious arsenate, especially in the range of As(III) ultra traces. The UV-assisted photooxidation of As(III) is performed by using titania layers, prepared by electrophoretic deposition of both commercial- and laboratory-made TiO2 nanopowders. This novel photocatalytic approach, based on immobilized particles, avoids the expensive filtration step, usually required in slurry systems.