Selective detection of Hg²⁺ ion in aqueous medium with the use of 3‐(pyrimidin‐2‐ylimino)indolin‐2‐one‐functionalized SBA‐15

Abstract

An isatin-based fluorophore, 3-(pyrimidin-2-ylimino)indolin-2-one, was grafted on a large-pore mesoporous silica material (SBA-15) via a two-step modification process. The obtained material (SBA-Is-Py) was characterized using various techniques and the characterization showed that the ordered porous structure was preserved after the post-grafting procedure. The optical sensing ability of SBA-Is-Py was studied upon the addition of a variety of metal ions and a marked fluorescence quenching by Hg 2+ ion was observed. SBA-Is-Py exhibited

Design of Multifunctional Fluorescent Hybrid Materials Based on SiO2 Materials and Core–Shell Fe3O4@SiO2 Nanoparticles for Metal Ion Sensing

“…B) Fluorescence spectra of MSNs‐ISN‐1 (3 mL H 2 O suspension, 0.2 g L −1 ) in the presence of various metal ions (100 µL, 1 × 10 −2 m , λ ex = 250 nm) i). Reproduced with permission . Proposed binding mode between MSNs‐ISN‐1 and Hg 2+ ii).…”

“…Proposed binding mode between MSNs‐ISN‐1 and Hg 2+ ii). Reproduced with permission . Copyright 2017, Wiley.…”

“…In 2017, Badiei and co‐workers reported hybrid MSNs functionalized with various ISN derivatives for specific metal ions sensing application . They developed an approach to construct a Hg 2+ ‐sensor, i.e., 3‐(pyrimidin‐2‐ylimino)indolin‐2‐one (ISN‐1) immobilized MSNs (MSNs‐ISN‐1), which displayed good sensitivity, selectivity, and reusability toward Hg 2+ and a good limit of detection of 3.28 × 10 −7 m . In the presence of Hg 2+ (100 µL, 1 × 10 −2 m ), the fluorescence intensity of MSNs‐ISN‐1 (0.2 g L −1 ) at 408 nm (λ ex = 250 nm) was quenched (Figure Bi) and Hg 2+ ions successfully coordinated with the carbonyl O, imino N, and pyrimidine nitrogen atoms to form a stable five‐membered metallocycle (Figure Bii).…”

“…Nowadays, ISN was extensively used in optical sensors, such as, ISN functionalized calixarene, rhodamine, semicarbazone molecular receptors for metal ion recognition . In 2017, Badiei and co‐workers reported hybrid MSNs functionalized with various ISN derivatives for specific metal ions sensing application . They developed an approach to construct a Hg 2+ ‐sensor, i.e., 3‐(pyrimidin‐2‐ylimino)indolin‐2‐one (ISN‐1) immobilized MSNs (MSNs‐ISN‐1), which displayed good sensitivity, selectivity, and reusability toward Hg 2+ and a good limit of detection of 3.28 × 10 −7 m .…”

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.…”