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

摘要

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 Au-Au bond length (R_(Au-Au)) can be influenced by the Cu concentration in the materials. Different R_(Au-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 Au_(89)Cu_(11) bimetallic nanoparticles exhibited ultra-high anti-interference performance on the detection of arsenic(Ⅲ).