Synthesis, characterization, and application of ZnO@SiO2-APTES core-shell composite for selective electrochemical detection of Pb2+ ions
Afef Dhaffouli, Pedro Salazar, Chama Mabrouk, Soledad Carinelli, Michael Holzinger, Houcine Barhoumi
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.