Synthesis, characterization, and application of ZnO@SiO2-APTES core-shell composite for selective electrochemical detection of Pb2+ ions

Abstract

This study focuses on improving the electrochemical performances for the detection of heavy metals such as Pb 2+ by using a silica-based nanomaterial. In order to do this, ZnO nanoparticles (core) were used as a seed for the chemical deposition of a SiO 2 shell. The nanomaterial was synthesized according to a core-shell configuration and the obtained particles were subsequently functionalized with (3-aminopropyl) triethoxysilane APTES to enhance their electrochemical sensing capabilities. The unique physical and chemical properties of these particles, such as their uniform porosity and their ability to detect Pb 2+ , were exploited. The resulting composite was characterized by scanning electron microscopy, X-ray diffraction, and infrared spectroscopy to analyze its morphology and chemical composition. An electrochemical characterization was also performed to evaluate the change in electrode properties with a ZnO@SiO 2 -APTES-modified glassy carbon electrode. The differential pulse voltammetry technique was used to determine the Pb 2+ ion concentration. After optimization, the electrochemical sensor based on ZnO@SiO 2 -APTES showed significant sensitivity and exceptional performance in the detection of Pb 2+ with a limit of detection of 0.1 nM. Moreover, the proposed electrochemical sensor was successfully applied in the determination of trace metal ions in real environmental samples. • ZnO@SiO 2 -APTES composite was successfully synthetized. • APTES-amplified amino groups enable low-concentration Pb 2+ detection. • Sensor remains robust in the presence of high metal ion concentrations. • Consistent 74 %-100 % recovery rates in complex environmental samples were obtained.