Enhanced electrochemical sensing arsenic(Ⅲ) with excellent anti-interference using amino-functionalized graphene oxide decorated gold microelectrode: XPS and XANES evidence

摘要

To date, the electrochemical method for efficient and accurate determination of As(Ⅲ) in groundwa ter with interference-free is still a difficultly but significantly task. Herein, a reliable, high sensitive and excellent anti-interference electrochemical sensing As(Ⅲ) with amino-functionalized graphene oxide (NH_2-GO) decorated gold (Au) microelectrode was developed in mild media with square wave anodic stripping voltammeter (SWASV). Taking advantage of the synergy between the strong absorption capa bility of NH_2-GO and the excellent electrocatalytic ability of Au microwire, the NH_2-GO modified Au microelectrode exhibits the enhanced electrochemical performance toward As(IH). No obvious interfer ence from other commonly coexisting ions on the determination of As(Ⅲ) was observed. Furthermore, the robust stability and reproducibility of the electrodes were obtained. Under the optimized conditions, the limit of detection (3б method) toward As(Ⅲ) was 0.162 ppb with a sensitivity of 130.631μAppb~(-1)cm~(-2). Notably, the possible mechanism of the enhanced stripping signal was preliminarily explored by using X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure (XANES) techniques. Finally, the analytical application of the raised means on the detection of As(Ⅲ) in Xingwangzhuang Village groundwater. Inner Mongolia, has been successfully verified.