Calix[4]arene-modified silica nanoparticles for the potentiometric detection of iron (III) in aqueous solution

This article aims to present the synthesis and the characterization of a novel hybrid material, based on silica nanoparticles, and which can be used as a sensitive element for the electrochemical detection of iron (III). This material was obtained by grafting an iron ligand-based calix[4]arene structure onto nanosized silica particles. The covalent anchoring of the chelator was obtained by nucleophilic coupling reaction between the modified calix[4]arene and the chloropropyl functionalized silica. The grafting reaction was confirmed by FTIR (DRIFT), solid-state 13 C Cross-Polarization MAS (CPMAS) NMR and thermal analysis. The interaction between the material and the dissolved iron (III) was demonstrated though potentiometric measurements. A linear evolution of the open circuit potential, which can be used analytically for iron (III) detection, has been obtained.