Electrochemical Detection of Trace Arsenic (III) by functionalized In0.38Ga0.62N/Si(1 1 1) electrode

We report here the electro-analytical potential of directly grown epitaxial In0.38Ga0.62N/Si(1 1 1) using cyclic voltammetry and impedance spectroscopy. Current characteristic of In0.38Ga0.62N electrode was found ∼400 times higher than that of bare Si(1 1 1) with reduced polarization resistance value of 15.2 kΩ, which is attributed to the available highly dense positively charged surface donor states promoting electron transfer. Further, we demonstrated for the first-time successful detection of arsenite with the detection limit of 9.27 ppb in the linear dynamic range of 10–50 ppb upon surface modification with MPA utilizing As-S bond chemistry. These preliminary results offer a rugged substitutional working electrode owing to excellent electrochemical characteristics over existing electrodes for toxic metalloids sensing in water.