High performance determination of Pb2+ in water by 2,4-dithiobiuret-Reduced graphene oxide composite with wide linear range and low detection limit

Abstract

In this work, a novel chelating adsorbent, 2, 4-dithiobiuret-reduced graphene oxide composite (DTB-RGO), was synthesized and worked as an electrochemical sensor for the determination of Pb²⁺. X-ray photoemission spectroscopy, Raman spectroscopy and Fourier transform-infrared spectroscopy were used to confirm the successful doping of the aminothiourea groups into the GO nanosheets through amide bond. The electrode modified with DTB-RGO shows two wide linear range 0.1-200 ng mL^-1, 200-1000 ng mL^-1 and relatively low detection limit 0.08 ng mL^-1 for Pb²⁺, far below the level of 10 ng mL^-1 proposed by WHO. This DTB-RGO modified electrode also presents satisfying selectivity, reproducibility, stability, and applicability for detection of Pb²⁺, providing a simple and promising platform to develop novel electrochemical sensor for detecting Pb²⁺ with higher performance.

Keywords: 2, 4-dithiobiuret; Anodic-stripping voltammetry; Electrochemical determination; Graphene oxide; Heavy metal ions; Pb(2+).