An electrochemical sensor based on a magnetic Fe3O4 nanoparticles and gold nanoparticles modified electrode for sensitive determination of trace amounts of arsenic(III)

A simple and sensitive method for the detection of arsenic(III) using a magnetic Fe3O4 nanoparticles and gold nanoparticles modified glassy carbon electrode (Au NPs/Fe3O4/GCE) was developed. The Fe3O4 nanoparticles were dropped onto a GCE and the gold nanoparticles were electrodeposited later. The resulting electrode surfaces were characterized with both field emission scanning electron microscopy (FESEM) and electrochemical impedance spectroscopy (EIS). Square wave anodic stripping voltammetry (SWASV) was performed for the determination of arsenic(III). The obtained results show that the sensitivity of arsenic(III) is significantly improved on Au NPs/Fe3O4/GCE in comparison with Au NPs/GCE. Under optimal conditions, the detection limit (S/N = 3) was 0.00097 μg L−1. In addition, the modified electrode exhibited excellent reproducibility and high stability. The developed method was successfully applied to determine arsenic(III) in real water samples with satisfactory results.