Isophtalic acid terminated graphene oxide modified glassy carbon nanosensor electrode: Cd²⁺and Bi³⁺analysis in tap water and milk samples

Abstract

In this study, graphene oxide was derivative with 5-aminoisophtalic acid by amidization reaction. The nanomaterial in suspension was denoted as graphene oxide-isophtalic acid. The graphene oxide-isophtalic acid suspension was covered on the glassy carbon electrode surface under the infrared lamb. The graphene oxide was characterized with transmission electron microscopy and x-ray diffraction. Surface characterization of the glassy carbon/graphene oxide-isophtalic acid was performed with x-ray photoelectron spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The ultrasensitive nanoplatform for the simultaneous electrochemical square-wave anodic stripping voltammetry assay of Bi3+ and Cd2+ in aqueous solution has been developed on the glassy carbon/graphene oxide-isophtalic acid. The linearity range of Bi3+ and Cd2+ were 1.0×10−8 – 1.0×10−12 M (S/N = 3). The responses of species were practically unaltered with the increase of various species concentration. The detection limits of Cd2+ and Bi3+ were determined as 8.1×10−13 M and 1.06×10−13 M, respectively. The electrode performance was checked with tap water and commercially milk samples.