Nanoporous Gold Microelectrode: A Novel Sensing Platform for Highly Sensitive and Selective Determination of Arsenic (III) using Anodic Stripping Voltammetry

A home-made gold microelectrode (Au-E) was fabricated and its surface was modified with nanoporous gold structures via a facile electrochemical approach (anodization followed by electrochemical reduction method). The fabricated nanoporous Au microelectrode (NPG-E) was used as a sensor probe for the determination of As(III) in 1.0 mol L-1 HCl solution using square wave anodic stripping voltammetry (SWASV) technique. Field emission scanning electron microscopy (FE-SEM) and cyclic voltammetry were used to characterize the surface morphology and assess the electrochemical surface area and the roughness factor of the NPG-mu E. SWASVs recorded with the NPG-E in As(III) solutions indicated linear behaviour in the concentration ranges of 10-200 mu g L-1 and 2-30 mu g L-1, with regression coefficients of 0.996 and 0.999 at a deposition time of 120s, respectively. The limit of detection (LOD) was found to be 0.62 mu g L-1 with high sensitivity of 29.75 mu A (mu gL(-1))(-1) cm(-2). Repeatability and reproducibility were also examined and values were determined as 3.2% and 9.0%. Negligible interference from major interfering copper ion was noticed, revealing the excellent anti-interference property of the proposed sensing platform. The developed NPG-mu E was successfully used for As(III) determination in tap water samples.