Construcción y Caracterización de Microelectrodos Nanoporosos de Oro para la Determinación de As (III) Utilizando Voltametría de Redisolución Anódica (ASV) con Aplicación en Aguas de Consumo Humano

Abstract

A gold microelectrode was fabricated and its surface was modified with nanoporous gold structures via a electrochemical approach of anodization followed by electrochemical reduction method. The fabricated nanoporous gold microelectrode was used as a sensor probe for the determination of As(III) in 1.0 mol•L-1 HCl solution using anodic stripping voltammetry joined to square wave voltammetry technique (SWASV). Field emission scanning electron microscopy and electorchemical analysis, by using cyclic voltammetry and hydrogen adsorption from solution were used to characterize the surface morphology and assess the electrochemical surface area and the roughness factor of the nanoporous gold electrode. SWASV recorded with the nanoporous electrode in As(III) solutions indicated linear behaviour in the concentration range of and 2-30 µg•L-1, with a regression coefficient of 0.9991 at a deposition time of 120 s. The limit of detection (LOD) was found to be 0.318 µg L-1. Repeatability and reproducibility were also examined and values were determined as 3.2 % and 8.9 %, respectively. Negligible interference from major interfering copper ion was noticed, revealing the excellent anti-interference property of the proposed sensing platform. Finally, a tap water sample was analized and noticed a concentration of 4•µg L-1, which is under the recommended máximum limit.