Red Mud-Reduced Graphene Oxide Nanocomposites for the Electrochemical Sensing of Arsenic

This work demonstrates the applicability of red-mud-reduced graphene oxide (RM-rGO) nanocomposites (NCs) for the reliable and selective electrochemical (EC) detection of arsenic. The new NC material shows excellent anti-interference activity toward arsenic (As3+) ions with the cooccurrence of other common cations (Cd2+, Cr2+, Zn2+, Pb2+, and Hg2+). Especially, the NC is exceptionally selective for As3+ ions in the presence of Cu2+ ions, which is stated to be the main interfering agent in the EC detection of As3+. Under optimal experimental conditions, the new NC displays a high sensitivity (2.49 μA ppb-1) as well as a very low detection limit (0.07 ppb) toward As3+ detection. This excellent EC performance of the composite is accounted for by the high adsorption proficiency of hematite (Fe2O3)-phase-rich red mud nanoparticles and enhanced electron-transfer kinetics due to the presence of rGO.