Voltammetric detection of arsenic on a bismuth modified exfoliated graphite electrode

We present the application of a bismuth modified exfoliated graphite electrode in the detection of arsenic in water. Bismuth film was electrodeposited onto an exfoliated graphite (EG) electrode at a potential of −600 mV. The modification of EG resulted in an increase in the electroactive surface area of the electrode and consequently peak current enhancement in Ru(NH3)62+/3+ redox probe. Square wave anodic stripping voltammetry was performed with the modified electrode (EG-Bi) in As (III) solutions at the optimum conditions of pH 6, deposition potential of −600 mV and pre-concentration time of 180 s. The EG-Bi was able to detect As (III) to the limit of 5 μg L−1and was not susceptible to many interfering cations except Cu (II). The EG-Bi is low cost and easy to prepare.