Electrochemical sensor based on graphdiyne is effectively used to determine Cd²⁺ and Pb²⁺ in water

In this work, graphdiyne, a new kind of carbon allotrope composed of sp and sp(2) hybridized carbon atoms, firstly worked as an effective electrochemical sensor for the determination of low concentration of Cd2+ and Pb2+ in water using electrochemical pre-enrichment and anodic-stripping voltammetry methods. The limit of detection was 0.46 nM for Cd2+ and 1.72 nM for Pb2+ with a linear range extended from 0.01 mu M to 1 mu M. This graphdiyne modified electrode also presented excellent selectivity, stability, applicability and reproducibility, providing a simple and promising platform to develop novel electrochemical sensor for detecting Pb2+ and Cd2+ with higher performance. Through X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared (FTIR) and X-ray absorption near edge structure (XANES) characterization, it was verified that the acetylenic links in graphdiyne served as adsorbent sites by providing electrons to bind with heavy metal ions, which enhanced the electrochemical sensing performance.