Growth of Cu-Doped CeO₂ Solid Solution Quantum Dots and Their Application for Trace Lead Detection

Abstract

Lead ions (Pb2+) are poisonous heavy metal pollutants that pose a constant threat to human health. To address this issue and develop a rapid and selective detection method for lead ions in various bodies of water, a highly sensitive sensor based on a glass carbon electrode modified with solid solution quantum dots (SSQDs) was constructed. The use of Cu-doped CeO2 SSQDs with extremely reduced size enhances the electroactive area due to their abundant edge sites and significant surface charge imbalance. The sensor exhibits exceptional sensitivity, selectivity, reproducibility, and stability for anodic stripping voltammetry analysis of Pb2+. Under optimal conditions, the sensor achieves a lower detection limit of 5.652 pM. In natural water samples, the recoveries of Pb2+ ranged from 97.6 to 105.0% with a relative standard deviation below 4.7%. The superior electrochemical performance of the sensor suggests its significant potential for detecting heavy lead ions in a variety of applications.