Flavone functionalized magnetic nanoparticles: A new fluorescent sensor for Cu2+ ions with nanomolar detection limit

Abstract

This paper presents the preparation and characterization of a new class of fluorescent core-shell magnetic nanoparticles composed of a Fe3O4 core, coated with amino-functionalized silica shell and modified with morin (Fe3O4@SiO2-NH2-morin). These nanoparticles were examined by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), zeta potential and vibrating sample magnetometer (VSM). The fluorescent magnetic nanoparticles were analyzed by UV-vis and fluorescence spectroscopy. The characterization data showed that the nanoparticle diameter is increased at each synthesis step (from 14 to 78 nm) and that all nanoparticles have superparamagnetic properties. The fluorescence response of morin-magnetic nanoparticle towards Cu2+ ions showed a significant and selective fluorescence quenching. Morin functionalized magnetic nanoparticle are found to be highly selective for Cu2+ ions whereas the interference from other metal ions and biological compounds was negligible. The nanosensor not only provided a sensitive (7.5 nM) and selective detection of Cu2+ ions, but a new fluorescent and biocompatible material with potential use in biological applications.