Bentonite clay; gold nanoparticles; arsenite oxidation; electrocatalysis; oxidative determination.
In the present manuscript, a simple and easy route to synthesize bentonite (bt) clay-supported goldnanoparticles (Au NPs) is reported (represented as Au-bt).Application of this new environmentally benignmaterial in electrocatalytic determination of arsenite (As(III)) was studied. The successful synthesis and incorporation of Au NPs into the bt clay is supported by spectroscopic, microscopic and electrochemical methods.The synthesized Au-bt material was used to modify glassy carbon electrode (GC) by the evaporation of Au-btaqueous suspension dropped on the surface of the GC (GC/Au-bt).Cyclic voltammetry and chronoamperometry studies of As(III) solutions were performed with this GC/Au-bt electrode which act as efficient platform forthe electro-oxidation of As(III) to As(V) at a very low overpotential. Kinetic parameters were evaluated for theoxidation of As(III) at the GC/Au-bt platforms.A wide linear calibration range for the determination of As(III)from 1 to 1700 μM was obtained with high reproducibility and stability. A limit of detection, 0.1 μM wasachieved with high sensitivity.Additionally, it showed a good selectivity for the determination of As(III) in thepresence of copper(II) and other interfering ions suggesting a promising new route for trace level determinationof As(III) in neutral conditions.