A highly sensitive and selective ON-OFF fluorescent sensor based on functionalized magnetite nanoparticles for detection of Cr(VI) metal ions in the aqueous medium

Herein, we developed a very sensitive and selective fluorescent magnetic nanoparticle sensor for the selective detection of Cr(VI) metal ions in aqueous solutions. Detection of Cr(VI) metal ions is based on fluorescence quenching mechanism of the BODIPY compound bearing magnetic nanoparticles in aqueous media. The newly synthesized BODIPY compound was characterized by H-1 and C-13 NMR. The morphology, chemical and physical properties of the prepared nanoparticles were performed by energy-dispersive X-ray (EDX), thereto gravimetric analysis (TGA), transmission electron microscopy (TEM), FT-IR spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Fluorescence and UV-visible spectroscopies were used to investigate the selectivity of the BODIPY immobilized magnetic nanoparticle and used to detect Cr(VI) metal ion in aqueous solutions. According to the characterization, the magnetic fluorescent super magnetic iron oxide nanoparticles (F-SPION) were revealed that the average particle diameter was about 18 nm. The newly prepared fluorescent superparamagnetic nanopartide (F-SPION) showed a fluorescence quenching response against Cr(VI) metal ions at pH 1 medium. The response of the magnetic fluorescent nanoparticle to target metal ion, Cr(VI), was highly selective, while possible interactions from other metal cations were insignificant. The fluorescence quenching of F-SPION in presence of Cr(VI) was completed in the first 5 min. These features provide potential uses of the prepared F-SPION as a new class of useful sensors for environmental applications. (C) 2020 Elsevier B.V. All rights reserved.