Facile Synthesis of Highly Sensitive Hybrid Nanomaterial Modified with a Fluorescent Probe for Detection of Fe3+ Ions

Abstract Herein, a highly sensitive nanosensor was developed by covalent grafting of Schiff base. (E)‐2,3‐dimethyl‐1‐phenyl‐4‐(pyridin‐2‐ylmethyleneamino)‐1,2‐dihydropyrazol‐5‐one (DPPDO) on the surface of mesoporous titanium, Mes‐TiO 2 , via an aminopropyl bridge to get Mes‐TiO 2 ‐NH 2 /DPPDO. The effective grafting was validated by different spectroscopic techniques. Using absorption, and emission measurements, the colorimetric and optical detection behaviors of several metal ions such as Mn 2+ , Fe 3+ , Zn 2+ , Ag + , Cd 2+ , Hg 2+ , Al 3+ , and Pb 2+ were investigated. By dispersing the nanosensor in an aqueous solution containing the metal ions of interest, the resulting solid materials exhibited high binding to Fe 3+ ions compared to other metal ions, resulting in dramatic fluorescence intensity up to 87 %. It showed quenching and yellow discoloration. When 0.2 M hydrochloric acid was added to the produced nanosensor‐Fe complex, the effect of the investigated nanosensor was reversible, restoring the original absorption and emission spectra of the free sensor. It is shown that there are solvent effects are also discussed for solvents of different polarities. Fluorescence quantum yields, fluorescence lifetimes, binding constants, and limit of detection were determined. In addition, reusability was evaluated to determine the adsorption efficacy of the nanosensor and was found to be effective seven times, suggesting that nanosensor is potential one for metal ion detection.