Graphene oxide-assisted synthesis of bismuth nanosheets for catalytic stripping voltammetric determination of iron in coastal waters

The article describes the synthesis of bismuth nanosheets (BiNSs) in the presence of a small quantity of graphene oxide (GO) which is helpful for the formation of two-dimensional BiNSs and improves dispersity. The material, when placed on a glassy carbon electrode (GCE), is shown to enable catalytic stripping voltammetric determination of total dissolved iron without the need for adding a complexing agent. The average thickness and length of the BiNSs are 3 to 4 nm and 100 to 200 nm, respectively. The unique nanostructure of the BiNSs, the ability of Bi to form alloys with metal, and the current amplification of the catalytic system make the modified GCE an excellent choice for electrochemical determination of Fe(III). Under the optimal conditions, the electrode has a linear response to Fe(III) in the 0.01 to 20 mu M concentrations range, with a lower detection limit of 2.3 nM. The electrode was successfully applied to the sensitive determination of Fe(III) in coastal waters.