Influence of Oxidation Stage and Exfoliation Extent of Carbon- Based Materials on Electrochemical Detection of As(III)

摘要

This study deals with the electrochemical detection of As(III) and especially with its interaction withcarbon-based materials such as graphene oxide, graphite oxide and partially reduced graphene oxide inconnection with the adsorption of As(III) to their surface. Using differential pulse voltammetry andatomic absorption spectrometry, it was found that the As(III) reaches the best adsorption efficiency onthe carbon-based materials surfaces at very acidic pH after 1 hour interaction. We decided to use thispromising ability of graphene oxide to design a new method for As(III) detection using a modifiedglassy carbon electrode (GCE). In order to enable detection of As(III), the surface of glassy carbonelectrode was firstly modified by gold nanoparticles (AuNPs). After this step the working electrodewas modified for with graphene oxide to enhance the electrochemical signal of As(III). Compared tothe working electrode modified only by gold nanoparticles, the electrochemical signal of As(III) on theGCE/AuNPs/GO increased by approx. 50%. Interaction time of As(III) on graphene oxide (located onthe surface of the working electrode) demonstrated the process of As(III) adsorption to the surface,which is manifested by increasing electrochemical signal of As(III) in individual time intervals.