Synthesis and characterization of quinoline-derivated fluorescent sol–gel-imprinted polymer as a chemosensor for sensing of uranyl ion

Abstract: In this work, chemosensor that contains 3-aminoquinoline derivative of silane coupling agent grafted to the sol–gel polymer has been synthesized and characterized for determination of the uranyl, UO22+ion. The quinoline-based fluorescence probe was covalently anchored to the surface of sol–gel polymer by a simple one-step procedure.The sol–gel polymer was characterized by FTIR spectroscopy, N₂ adsorption–desorption analysis, scanning electron microscope, particle size distribution, and optical microscope by comparing with ion-imprinted sol–gel polymer obtained in the presence of UO22+ion. Surface area, pore volume, and diameter were analyzed from the profile of nitrogen adsorption. Conductometric and potentiometric titrations were carried out to evaluate the active concentration of functional precursor immobilizedwithin the sol–gel matrix. The pH-dependent fluorescence behavior of sol–gel polymer both in the absence and presence of UO22+ ion was elucidated to optimizethe conditions for the sensing of UO22+ion in aqueous solution. The chemosensor exhibits singlefluorescence emission belonging to quinoline group in sol–gel polymer,whereas it demonstrates dual emission in the presence of UO22+ion. It was observed that the peak belonging quinoline group was quenched while the peak at longer wavelength enhanced upon interaction with UO22+ion. Graphical Abstract: [InlineMediaObject not available: see fulltext.]