Phthalocyanine-Functionalized Magnetic Silica Nanoparticles as Anion Chemosensors

Abstract

Anionic species are one of the most common pollutants in residual and freshwaters. The presence of anthropogenic anions in water drastically increases the toxicity to living beings. Here, we report the preparation of a new optical active material based on tri(tosylamino)phthalocyanines grafted to ferromagnetic silica nanoparticles for anion detection and removal. The new unsymmetrical phthalocyanines (Pcs) proved to be excellent chemosensors for several anions (AcO−, Br−, Cl−, CN−, F−, H2PO4−, HSO4−, NO2−, NO3−, and OH−) in dimethyl sulfoxide (DMSO). Furthermore, the Pcs were grafted onto magnetic nanoparticles. The resulting novel hybrid material showed selectivity and sensitivity towards CN−, F−, and OH− anions in DMSO with limit of detection (LoD) of ≈4.0 µM. In water, the new hybrid chemosensor demonstrated selectivity and sensitivity for CN− and OH− anions with LoD of ≈0.2 µM. The new hybrids are easily recovered using a magnet, allowing recyclability and reusability, after acidic treatment, without losing the sensing proprieties.

Fluorescence Based Comparative Sensing Behavior of the Nano-Composites of SiO2 and TiO2 towards Toxic Hg2+ Ions

“…The literature citation revealed that 2θ value of amorphous silica depends upon temperature treatment and water to tetraethoxysilane (TEOS) ratio. Our measured 2θ values of silica were found to analogous to the reported 2θ value of silica [61]. Further, the XRD studies of the APTES functionalized silica (9) and nano-composites (11) showed 2θ at 23 • only with increase in peak intensities confirmed the immobilization of APTES and organic ligand (3) on silica surface with confined amorphous character of silica.…”

Sulfonamide functionalized silica nano-composite: characterization and fluorescence “turn-on” detection of Fe3+ ions in aqueous samples

“…As a consequence, it was depicted that the non-crystalline character of Stöber silica was remained intact even after modifications with APTES and organic moiety, showed that silica nanospheres were enough stable to conduct surface chemical reactions. However, the XRD peak intensities declined from silica to APTES@SiO 2 to SAN (6), illustrating that APTES and sulfonamide were sequentially immobilized over the silica particles [45].…”

Applications of Fluorous Porphyrinoids: An Update†

“…Functionalized metalloporphyrins can interact with many different cations and anions, changing their structures and photophysical properties as a result. Fluorinated porphyrinoids have been developed as sensors due to their photophysical, electrochemical and molecular recognition properties (149,150,151,152,153). Cations like mercury(II) and lead(II) and anions like cyanide and arsenate are considered pollutants and serious environmental threats.…”

“…Building on this chemosensor work as well as the same group’s previous work with magnetic nanoparticles, Rodrigues et al . investigated the functionalization of silica‐coated Fe 3 O 4 NPs with zinc phthalocyanines to serve as optical sensors for harmful anions (153). As with the previous studies (77,78), aminopropyl groups attached to the silica coating of the NP served as nucleophiles to substitute an asymmetric A3B‐type phthalocyanine.…”