Design of a High-Performance Electrochemical Sensor Using ZnO@SiO₂-n-propyl-NH₂-benzotheura-AuNPs for the Selective and Sensitive Detection of Lead Ions in Environmental Samples

This study presents the development of an innovative electrochemical sensor based on AuNPs-decorated ZnO@SiO₂ and functionalized with n-propyl-NH₂-BTU for the selective detection of lead ions. The synthesized material was characterized by transmission electron microscopy, scanning electron microscopy, and X-ray diffraction, which confirmed the successful incorporation of gold nanoparticles (AuNPs). Electrochemical measurements, using differential pulse voltammetry, revealed excellent selectivity of the modified electrode for Pb²⁺ ions in the presence of competing metal ions. The sensor exhibited a low detection limit of 8.02×10-10M, calculated using the standard 3S/b method, and demonstrated three distinct linear ranges: 1×10-9 to 1 ×10-7 M, 1×10-7 to 5×10-7 M, and 5×10-7 to 2.5×10-6 M, highlighting its sensitivity over a broad concentration spectrum. Additionally, recovery experiments in tap water yielded recovery rates ranging from 82% and 116%, confirming reliability and reusability. These findings emphasize the sensor’s strong potential for accurate Pb²⁺ monitoring in environmental samples.