Highly sensitive and selective fluorescent detection of rare earth metal Sn(II) ion by organic fluorine Schiff base functionalized periodic mesoporous material in aqueous solution

•We first develop Schiff base functionalized mesoporous materials via co-condensation.•A novel Schiff base based on 5-fluoroisatin is prepared.•High sensitive and selective fluorescent detection of Sn2+ ion is accomplished in aqueous media.•A good linearity between the fluorescence intensity and the concentration of Sn2+ ion is constructed.•The fluorescent intensity of mesoporous materials with the amount of Schiff base is optimized.

A Schiff base 3-((4-aminophenyl)imino)-5-fluoroindolin-2-one (APIFI) functionalized mesoporous material (APIFI-SBA) has been first developed by covalent binding with epoxypropoxyl groups on the inner surface of siliceous wall. The obtained material has been characterized by small angle X-ray diffraction, nitrogen adsorption–desorption and Fourier transform infrared spectroscopy. The results indicate that the Schiff base molecule APIFI is successfully immobilized within the channels of mesoporous material with linked ligand. Moreover, the ordered porous structure of mesoporous host is still retained on the Schiff base functionalized mesoprous material. The material APIFI-SBA shows high sensitivity and selectivity of detecting Sn2+ ions in aqueous media. A good linearity between the fluorescence intensity of the material and the concentration of Sn2+ ion is constructed, which enables it as a fluorescent chemosensor for detecting Sn2+ ion in aqueous solution. In future, it is potential to be used as a novel chemosensor for a lot of practical applications in chemical, environmental and biological systems.

Graphical abstractA Schiff base 3-((4-aminophenyl)imino)-5-fluoroindolin-2-one (APIFI) functionalized mesoporous material (APIFI-SBA) has been first developed by covalent binding with epoxypropoxyl groups on the inner surface of siliceous wall via co-condensation method. Moreover, the ordered porous structure of mesoporous host is still retained after immobilizing the Schiff base within the channels. The material APIFI-SBA shows high sensitivity and selectivity of detecting Sn2+ ions in aqueous media. A good linearity between the fluorescence intensity of the material and the concentration of Sn2+ ion is constructed, which enables it as a fluorescent chemosensor for detecting Sn2+ ion in aqueous solution.Figure optionsDownload full-size imageDownload as PowerPoint slide