Synthesis, characterization, sensing performance, and computational insights of a new heterogeneous ionic liquid of SBA-Pr-Py-Car for selective and sensitive detection of Hg2+ ions

Abstract

In this study, a novel heterogeneous ionic liquid of SBA functionalized as SBA-Pr-Py-Car was designed by the Functionalization of SBA-15 with (3-Chloropropyl)trimethoxysilane, and then 3-methyl-1-phenyl-5-oxo-1H-pyrazole-4 carbaldehyde. The structural and physicochemical properties of the SBA-Pr-Py-Car composite were characterized using TGA, XRD, SEM, EDX, and N₂ adsorption–desorption analyses. These techniques confirmed its thermal stability, elemental composition, tubular morphology, retention of the SBA-15 framework, and key structural features, respectively. The sensing performance of the material was evaluated via fluorescence spectroscopy. The results demonstrated a significant quenching of fluorescence intensity in the presence of Hg2+ ions, while no notable response was observed with other metal cations, indicating high selectivity. The ability to detect Hg2+ ions through fluorescence offers a rapid, sensitive, and cost-effective method for monitoring this hazardous contaminant in environmental and biological samples. Such detection is crucial for safeguarding both human health and ecological systems. The calculated detection limit for Hg2+ was obtained at 6.25 × 10−7 M, indicating the good sensitivity of the chemosensor. The structural optimization was performed using a computational perspective with the help of 6-311 g (d,p)/LANL2DZ level to verify the interaction mechanism. Furthermore, key physio-chemical parameters were derived from the calculated energies of molecular orbitals. © 2025 Elsevier B.V., All rights reserved.