Efficient Optical and UV–Vis Chemosensor Based on Chromo Probes–Polymeric Nanocomposite Hybrid for Selective Recognition of Fluoride Ions

[Image: see text] A novel colorimetric sensor based on the TiO(2)/poly(acrylamide-co-methylene bis acrylamide-co-2-(3-(4-nitro-phenyl)thioureido)ethyl methacrylate) nanocomposite was synthesized via a surface modification strategy; methacryloxypropyltrimethoxysilane was used to provide reactive vinyl groups on the surface of TiO(2) nanoparticles for the successful surface polymerization of Am (acrylamide), MBA (methylenbisacrylamide), and NPhM (2-(3-(4-nitrophenyl)thioureido)ethyl methacrylate) components. The successful preparation of nanocomposites was confirmed using Fourier transform infrared, (1)H NMR, (13)C NMR, scanning electron microscopy, transmission electron microscopy, thermogravimetry analysis, and X-ray diffraction methods, and the sensing ability of the probe toward fluoride ions was investigated using naked-eye detection and UV–vis measurement. The interaction of the prepared polymeric nanocomposite with fluoride ions elicited a significant visible change in color from pale yellow to orange and was further affirmed by a clean interconversion of the two absorption bands at 330 and 485 nm. The selective binding ability of the polymeric nanocomposite towards fluoride over other anions, such as I(–), Cl(–), Br(–), AcO(–), H(2)PO(4)(–), and H(2)SO(4)(–) was further explored; the prepared chemosensor could detect fluoride ions in acetonitrile with a detection limit of 3 μM.