Electrochemical determination of arsenic(III) with ultra-high anti-interference performance using Au–Cu bimetallic nanoparticles

Abstract

Bimetallic nanoparticles provide a new opportunity for enhancing electrocatalytic activity because of some possible synergetic effects. In this study, different compositions of Au–Cu bimetallic nanoparticles are prepared via a simple hydrothermal method. The structure of Au–Cu bimetallic nanoparticles is characterized by using X-ray absorption fine structure (XAFS) techniques, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The correlations between electrochemical performance and the compositions of Au–Cu bimetallic nanoparticles on the determination of arsenic(III) are investigated through square wave anodic stripping voltammetry (SWASV). It is found that the amount of copper (Cu) in Au–Cu bimetallic nanoparticles is critical to the detection of arsenic(III). The XAFS results indicated that the AuAu bond length (RAu–Au) can be influenced by the Cu concentration in the materials. Different RAu–Au of Au–Cu nanoparticles lead to the different electrochemical catalytic activity toward arsenic(III), further revealing the different electrochemical behavior. Compared with Au nanoparticles and commercial Au electrode, the Au–Cu bimetallic nanoparticles showed enhanced electrochemical performance with high sensitivity at ppb level, low detection limit. Moreover, the Au89Cu11 bimetallic nanoparticles exhibited ultra-high anti-interference performance on the detection of arsenic(III).