A reduced graphene oxide supported Au-Bi bimetallic nanoparticles as an enhanced sensing platform for simultaneous voltammetric determination of Pb (II) and Cd (II)

A reduced graphene oxide supported Au-Bi bimetallic nanoparticles (rGO/Au-Bi) have been synthesized and employed as a novel sensing platform for electrochemical determination of Pb 2+ and Cd 2+ simultaneously. The successful formation of rGO/Au-Bi nanocomposites was investigated by means of transmission electron microscopy and X-ray photoelectron spectroscopy. At the rGO/Au-Bi nanocomposites modified electrode, two well-resolved voltammetric peaks for Pb 2+ and Cd 2+ were observed in differential pulse anodic stripping voltammetry (DPASV) measurements. Under the optimized conditions (pH 4.5, deposition potential −1.0 V, deposition time 200 s), the DPASV response currents demonstrated good linearity with the concentration of Pb 2+ (0.1–500 μg L −1 ) and Cd 2+ (0.1–300 μg L −1 ). The detection limits was 0.05 μM for Pb 2+ and 0.02 μM for Cd 2+ , respectively. In addition, the proposed electrode exhibited outstanding resistance to potentially interferents, high stability and excellent repeatability. Satisfactory application of proposed electrode was also demonstrated by the determination of Pb 2+ and Cd 2+ in real river water samples.