Synthesis and fluorescence study of the grafted salicylidene Schiff base onto SBA-15 mesoporous silica for detecting Zn2+ traces in aqueous medium

Abstract

A selective fl uorescent chemosensor was prepared by anchoring pyridine-2-carbaldehyde Schiff base ligand onto mesochannels of organically modifi ed SBA-15 mesoporous silica. The resulting organic-inorganic hybrid mesoporous chemosensor was characterized by X-ray diffraction, Fourier transform IR spectroscopy, transmission electron microscopy, UV-visible diffuse refl ectance spectra, and photoluminescence spectra. All the results support the idea that successive attachment of the ligand moiety onto one-pot-modifi ed mesoporous scaffold has not altered its basic hexagonally arranged structure. Upon introducing trace amounts of zinc ions into aqueous solution, remarkable enhancement in the fl uorescence was observed.

Recent Advances in the Preparation and Applications of Organo‐functionalized Porous Materials

“…This could help to have the detection limit of 1.6××10 −9 M for the fluoride ions . In another study, Schiff base complex was immobilized over salicylidene functionalized SBA‐15 materials which were later employed as fluorescent chemosensors and showed a great promise for the selective detection of even a trace amount of Zn ions . In another report, Karimi et al .…”

Fluorescence study of 5-nitroisatin Schiff base immobilized on SBA-15 for sensing Fe3+

“…Moreover, for chemosensor applications [27][28][29][30][31][32][33], the regularly arranged pores in its SBA-15 mesostructure can enhance the selectivity to particular guests like organic substance and/ or metal ions [34]. For Schiff base ligands as fluorescent chemosensors in the hybrid mesoporous silica materials, several reports have been published for sensing Al 3+ [35], Hg 2+ [36], Pb 2+ [37], Zn 2+ [38][39][40], and Cu 2+ ions [41][42][43]. In particular, Wang et al [44] and Afshani et al [45] have reported that the grafting of bis-Schiff base N,N′-(1,4-phenylenedimethyli-dyne)bis(1,4-benzenediamine) (PMBA) and salicylaldehyde with SBA-15 can be used for sensing Fe 3+ at a less intense blue-emission peak of the binding site consisting of a broad peak.…”