Green synthesis of a silver nanoparticle–graphene oxide composite and its application for As(iii) detection

Abstract

We report a facile and green synthetic approach to synthesize a silver nanoparticle (AgNPs)–graphene oxide (GO) composite using beta cyclodextrin as a stabilizing agent and ascorbic acid as a reducing agent. Further, we demonstrate its application as a highly sensitive and selective electrochemical sensor for selective determination of As(III) in the presence of other elements, such as Cu and some organic and inorganic molecules. The GO sheets provided the surface for the reduction of silver ions. The composite can be easily used for the construction of a disposable electrochemical sensor on a glassy carbon electrode (GCE) using a drop deposition method. The composite was characterized by scanning and transmission electron microscopies, energy dispersive X-ray spectroscopy, X-ray diffraction and electrochemical impedance spectroscopy. Cyclic voltammetry and anodic stripping voltammetry measurements were employed to evaluate the electrochemical properties of beta cyclodextrin stabilized AgNPs–GO/GCE towards arsenic(III) detection. The AgNPs–GO film exhibited distinctly higher activity for the anodic stripping analysis of As(III) compared to the GO film alone with approximately three times enhancement of the peak current. This nanostructured electrode applied for As(III) analysis displayed a wide linear range (13.33–375.19 nM), a high sensitivity (180.5(μA μM⁻¹)) including a 0.24 nM detection limit. We demonstrate the real-life application of the developed sensor by selectively determining the As content in ground and river water samples.