Novel carbon/manganese oxide nanocomposite for electrochemical detection of arsenic in water- a step towards portable real time sensor

Arsenic (As), is a worldwide societal & environmental threat and therefore requires continuous monitoring in the natural water resources. Although, many opto/electrochemical techniques based on, macro, micro and nanostructures have been developed for the detection of As³⁺ ions, with advantages of high selectivity, sensitivity, and fast response. Yet, most of them are commercially unavailable, expensive and requires harsh operational conditions. Herein, we report ours first results on novel nanocomposite (NC) material, reduced graphene oxide (rGO)/manganese oxide (MNO₂), for sensitive and selective detection of As (III) in water. The novel MnOx/rGO nanocomposite based working electrode is fabricated by one step electrochemical reduction method and characterized for its optical, structural and electrical properties. Results demonstrated a reduction peak at -1.4 V in sodium sulfate electrolyte, confirming simultaneous reduction of manganese and grapheme oxide (GO) on GO modified glassy carbon electrode. Preliminary sensing results revealed, sensitivity of fabricated electrode towards As (III) by appearance of stripping peak at ~ 0.26 V in square wave anodic stripping voltammetry (SWASV). Furthermore, sensing parameters such as time, pH, and deposition potential are optimized, which are recorded to design a portable embedded system for As (III) sensing.