In situ Bi/carboxyphenyl-modified glassy carbon electrode as a sensor platform for detection of Cd2+ and Pb2+ using square wave anodic stripping voltammetry.

Herein, a sensor platform, Bi/carboxyphenyl-modified glassy carbon electrode (Bi/CP/GCE), is presented for the detection of Cd2+ and Pb2+ using square wave anodic stripping voltammetry (SWASV). The sensor was obtained through electrografting of the GCE using 4-carboxybenzene diazonium tetrafluoroborate (4-CBD) and in situ electrodeposition of Bi3+. The stability of the grafted layer and the proposed mechanism of interaction between the metal ions and the grafted layer is supported by DFT calculations. Under the optimized conditions, Pb2+ had a linear working range of 25–500 μg L−1 with LOD of 10 μg L−1 (S/N = 3) and Cd2+ provided linear range of 50–500 μg L−1 and LOD of 25 μg L−1. The fabricated electrode presented good repeatability and reproducibility. The applicability of the electrode was tested for determination of Cd2+ and Pb2+ in tap water resulting in recoveries of 96.2–101% for Cd2+ and 98.1–104% for Pb2+.