Anti-adsorption properties of gold nanoparticle/sulfonated graphene composites for simultaneous determination of dihydroxybenzene isomers

Abstract

In this work, the simultaneous determination of dihydroxybenzene isomers of hydroquinone and catechol at the gold nanoparticle/sulfonated graphene modified electrode was reported. The gold nanoparticle/sulfonated graphene composites were prepared by electrostatic self-assembly of positively charged gold nanoparticles on negatively charged graphene sheets. The application of the composites for the electrocatalysis of hydroquinone and catechol was studied by cyclic voltammetry and differential pulse voltammetry. Compared to the well-known graphene modified electrode, including chemically reduced sulfonated graphene and electrochemically reduced graphene, the composites modified electrode exhibited obvious anti-adsorption properties toward aromatic species of hydroquinone and catechol. The results showed that the isomers could be detected selectively and sensitively at the composites modified electrode with an anodic peak-to-peak separation of about 110 mV. The linear range of hydroquinone and catechol was 5 to 100 μM and the detection limit was 1 μM and 2 μM, respectively. Simultaneous determination of hydroquinone and catechol in tap water samples has been studied. The attractive electrochemical performances and facile preparation methods have made this novel electrode promising for the development of effective dihydroxybenzene sensors.