Selectivity For Fe3 Research Articles

A Quinazolinone based fluorescent chemosensor for selective detection of Fe(III) in aqueous media: Applications to pharmaceutical and environmental analysis

ABSTRACTA Quinazolinone based chemosensor 2-(1,3-thiazol-2-yl)-2,3-dihydroquinazolin-4(1 H)-one (1) has been synthesized, that exhibits high sensitivity and selectivity for Fe3+ over other environmentally and biologically relevant metal ions by the changes in fluorescence properties and reversible with the addition of EDTA. Under the optimized conditions, Stern-Volmer plot gives a good relationship between chemosensor 1 and Fe3+ with detection limit 0.0366 µg.mL−1. The binding mode of 1 toward Fe3+ has been investigated by Job's plot, Benesi-Hildebrand plot, FTIR spectra measurements and theoretically supported by DFT calculations. Moreover, the sensor was successfully `applied for quantitative determination of Fe3+ ions in pharmaceutical and water sample.

Pyronin B‐Graphene Oxide‐Based Turn‐On Fluorescent Sensors for Fe3+ in an Aqueous Medium: Synthesis and Living Cell Application

AbstractPyronin B (PyB)–graphene oxide (GO) is reported for metal‐ion sensing since it is based fluorescent sensor. PyB–GO nanocomposites are synthesized in aqueous solution by Ultrasonic Homogenizers. The structure of PyB–GO nanocomposites is characterized with X‐ray diffraction (XRD),Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, UV–vis spectroscopy and Fluorescence Microscopy. PyB–GO binary system are studied for the sensing ability in the detection of metal ions as a fluorescent sensor. It shows high sensitivity and selectivity for Fe3+ metal ions in aqueous medium as a result of the spectroscopic data.

Selective and sensitive morpholine-type rhodamine B-based colorimetric and fluorescent chemosensor for Fe(III) and Fe(II)

The development of chemosensor materials is crucial for the early detection of hazardous materials, such as heavy metal ions and infectious viruses. In this study, three rhodamine B (RhB) derivatives (referred to as Rh-OS, Rh-OO, and Rh-SO) bearing a morpholine-type 6-membered ring as colorimetric, fluorescent sensors were synthesized, and fluorescence responses to various metal ions (Fe3+, Fe2+, Pb2+, Cr6+, Ce2+, Mn2+, Cd2+, Hg2+, K+, Na+, Mg2+, Li+, Ca2+, As3+, Co2+, Cu2+, Ni2+, and Zn2+) were investigated. Rh-OS, Rh-OO, and Rh-SO exhibited high sensitivity to Fe2+ and Fe3+, with the formation of a 1:1 (ligand: metal) complex, as evidenced by the UV–vis absorption and photoluminescence spectra. Luminescence turn-on was explained by the transfer of resonance energy from the morpholine-type moiety to the RhB framework. In addition, the selectivity of Fe3+ and Fe2+ was evaluated by 2D and 3D photoluminescence imaging.

A highly sensitive and selective fluorescence chemosensor for Fe3+ based on rhodamine and its application in vivo imaging

We synthesized a rhodamine-based fluorescent probe 1, which could be used for the optical detection of Fe3+. Compared with other commonly coexistent metal ions in aqueous system, it exhibited high sensitivity and selectivity for Fe3+, and the detection limit was only 4.2×10−8M. In addition, the rapid enhancement of fluorescence intensity on addition of Fe3+ provided a good method for the detection of Fe3+. What’s more, the colour change was visible and distinct, so it could be used for the naked-eye detection of Fe3+. Furthermore, the fluorescent probe was proved to be effective when used for sensing Fe3+ in living cells and zebrafish. These results showed its values in biological aspects.

An unusual “off-on” fluorescence sensor for iron(III) detection based on fluorescein–reduced graphene oxide functionalized with polyethyleneimine

Polyethyleneimine (PEI)–modified reduced graphene oxide (rGO) based fluorescent sensor is reported for metal-ion sensing. PEI–rGO nanocomposites are synthesized by a facile and controllable method using hydrazine hydrate as a main reducing agent and PEI that is a reducing agent, surface modifier and polymer host. The formation of PEI–rGO nanocomposites is confirmed with X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, UV–vis spectroscopy, Zeta potential measurements and Dynamic Light Scattering (DLS) analysis. Afterward, the interaction of fluorescein (FL) with PEI–rGO nanocomposites in aqueous dispersion, leading to the formation of FL/PEI–rGO ternary system, are studied at various conditions by using UV–vis absorption, steady-state and time-resolved fluorescence spectroscopies. It is observed that the photophysical properties of FL are dependent on the amount of both FL and PEI–rGO nanocomposites. The sensing ability of FL/PEI–rGO ternary system are examined in the detection of metal ions as a fluorescent sensor. The spectroscopic data reveal that the FL/PEI–rGO ternary system shows high sensitivity and selectivity for Fe3+ ions in aqueous solution. The detection limit for Fe3+ are determined to be 1.12μM.

Self-assembly of benzimidazole-Ended nano hyperbranched polyester and its Host-guest response

Hyperbranched aromatic-aliphatic polyester HBPE-BBA was synthesized by modifying the periphery of a second-generation hyperbranched polyester (HBPE) with benzimidazole (BBA) end groups. HBPE-BBA showed interesting self-assembly behaviors, and retained one-dimensional nano bead-on-string fibers and two-dimensional helical nanocoil morphologies in different solvents. The fluorescence results indicated that HBPE-BBA exhibited remarkable selectivity for Fe3+ and fused ring compounds.

A fluorescent sensor based on quinazoline ketone derivatives for selectivity of Fe3+

In this work, we provided a fluorescent sensor based on a compound containing fluorophore quinazoline ketone for detecting metal ions. 2-Methyl-4(3 H)-quinazoline thione was synthesised as a fluorescent probe for tervalent ferric ion (Fe3+) detection. Fluorescent determination of 2-methyl-4(3 H)-quinazoline thione indicated its maximum emission wavelength of 306.5 nm. The fluorescence interference and titration experiments have shown that the compound has a high selective fluorescence response to Fe3+. With an increase in the Fe3+ ion concentration, the fluorescence emission strength gradually weakened, and a slight red shift appeared. With Job’s method, 2-methyl-4(3 H)-quinazoline thione was proved to form a 1:2 complex with Fe3+. The results revealed that 2-methyl-4(3 H)-quinazoline thione could be used as a fluorescent probe for the recognition of Fe3+ with high selectivity.

Antimicrobial studies and ion exchange properties of copolymer resin derived from p-HBBF

p-Hydroxybenzaldehyde–biuret–formaldehyde (p-HBBF) copolymer resin was synthesized through the condensation of p-hydroxybenzaldehyde and biuret with formaldehyde in the presence of hydrochloric acid as a catalyst and with various molar ratios of the reacting monomers. The resulting copolymer was characterized with UV-visible, FTIR, 1H-NMR and C13 NMR spectral data, employed to determine the reactivity of monomers. The average molecular weight of this resin was determined with conductometric titration in a nonaqueous medium. The chelating ion-exchange properties were also studied with the batch equilibrium method. The chelating ion-exchange properties of this copolymer was studied for seven metal ions (Cu2+, Ni2+, Cd2+, Co2+, Zn2+, Pb2+ and Fe3+). The study was carried out over a wide pH range and in media of various ionic strengths. The copolymer showed a higher selectivity for Fe3+ ions than that for Cu2+, Ni2+, Cd2+, Zn2+ and Pb2+. The surface morphology of the copolymer resin was examined by scanning electron microscopy, and it establishes the transition state between crystalline and amorphous phases. The p-HBBF copolymer resin was tested for its inhibitory action against pathogenic bacteria and fungi. The resin shows potent inhibitory action against bacteria, such as Escherichia coli, Klebsiella sp (NCIM 2719) and Pseudomonas aeruginosa, and fungi, namely, Candida albicans and Penicillium sp.

Ion exchange study of some new biphenol–thiourea–formaldehyde terpolymer resins

Abstract Terpolymer resins, synthesized by reacting 2,2′-dihydroxybiphenyl with thiourea and formaldehyde in presence of HCl as catalyst, proved to be selective chelating ion-exchange resins for certain metal ions. Chelating ion-exchange properties of these terpolymer were studied for Fe3+, Cu2+, Ni2+, Co2+, Zn2+, Cd2+ and Pb2+ ions. A batch equilibrium method has been employed in the study of the selectivity of metal ion uptake involving the measurements of the distribution of a given metal ion between the polymer sample and a solution containing the metal ion. The study was carried out over a wide pH range and in media of various ionic strengths. The terpolymer showed higher selectivity for Fe3+, Cu2+ and Ni2+ ions than for Co2+, Zn2+, Cd2+ and Pb2+ ions.

Bis-Coumarins Bridged by Thiocarbazide as Novel Fluorescent Sensor for Fe <sup>3+</sup>

A novel coumarin-based fluorescent sensor CFe1 containing imine and thiourea groups was designed and synthesized. It showed good sensitivity and selectivity for Fe3+ ion over other commonly coexistent metal ions with fluorescent enhancement and blue-shift.

Selective catalytic reduction of NO by ethanol: Speciation of iron and “structure–properties” relationship in FeSiBEA zeolite

The speciation of iron in FeSiBEA zeolites is investigated in order to evidence the “structure–properties” relationship in the selective catalytic reduction (SCR) of NO by ethanol. FexSiBEA zeolites are prepared in acidic (pH 2.5) (x=0.3, 0.9 and 4.2Fewt%) or basic (pH 10) (x=3.6Fewt%) conditions by a two-step postsynthesis method which allows to incorporate Fe into zeolite, as evidenced by XRD. For low Fe content (Fe0.3SiBEA, Fe0.9SiBEA), iron incorporated as Fe(III) ions generates Brønsted acidic sites as shown by FTIR of pyridine. Framework tetrahedral Fe(III) ions are evidenced by diffuse reflectance UV–vis, XANES and EXAFS. For higher Fe content (Fe4.2SiBEA), beside tetrahedral Fe(III) ions which are dominant, octahedral Fe(III) species are also present as shown by DR UV–vis, XPS and EXAFS. In contrast, for Fe3.6SiBEA prepared in basic condition (pH 10), an extra-framework Fe(III) oxide phase is mainly observed.The catalytic activity of FexSiBEA in the SCR of NO by ethanol strongly depends on the speciation of iron and a structure–properties relationship has been evidenced. Fe0.3SiBEA and Fe0.9SiBEA which mainly contain framework tetrahedral Fe(III) ions are active, with selectivity toward N2 exceeding 90% for NO conversion from 25% to 55%. When additional octahedral Fe(III) species are present (Fe4.2SiBEA), the full oxidation of ethanol and NO by O2 becomes important, with CO2 and NO2, respectively, appearing at the expenses of N2. The NO conversion linearly depends on Fe concentration assuming a first order reaction, suggesting that tetrahedral and octahedral Fe(III) species are well dispersed, as confirmed by XRD. The iron oxide phase is quite inactive, the activity and selectivity of Fe3.6SiBEA being governed by the small amount of tetrahedral Fe(III) ions.

Phosphonate-Functionalized Polyfluorene as a Highly Water-Soluble Iron(III) Chemosensor

An anionic, phosphonate-functionalized polyfluorene, i.e., poly(9,9-bis(3′-phosphatepropyl)fluorene-alt-1,4-phenylene) sodium salt (PFPNa), has been synthesized by copolymerization of phosphonic acid-substituted 2,7-dibromofluorene and phenyldiboronic ester via direct Suzuki polycondensation reaction in DMF/water. Polymer PFPNa is highly soluble and emissive in water with a solubility of 60 mg/mL and a photoluminescence quantum yield of 75%. The absorption and fluorescence spectra of PFPNa are strongly dependent on pH value owing to the partial protonation of phosphate groups and the aggregation of the polymer chains. In aqueous media polymer PFPNa shows high sensitivity and selectivity for Fe3+. A 400-fold fluorescence quenching was achieved upon adding Fe3+ into its aqueous solution. Most importantly, ultrathin multilayer films constructed by alternatively depositing polyanionic PFPNa and polycationic poly(diallyldimethylamine) via the layer-by-layer (LbL) self-assembling method are stable and highly sensitive to Fe3+ with a sensitivity up to 10−7 M.

Preparation, characterization and application of a new type of ion exchanger and solid acid zirconium sulfonated oligo-polystyrenylphosphonate-phosphate supported on ZrO2

Abstract The new type of ion exchanger and solid acid zirconium sulfonated oligo-polystyrenylphosphonate-phosphate (ZSPSP) supported on ZrO2 (ZSPSP/ZrO2) was prepared and characterized by IR, SEM, TG and DSC. The thermal analysis indicated that the ZSPSP/ZrO2 could be used safely below 200 °C. SEM micrographs demonstrated that ZSPSP/ZrO2 with 1–100 μm of particle diameter was amorphous and microporous structure. Comparing with mineral acids such as H2SO4 and HCl or classical resins such as Amberlyst-15 and Nafion NR50 in the esterification reaction between acetic acid and 1-butanol, the order of catalytic activities was: H2SO4 > HCl > ZSPSP/ZrO2 > Amberlyst-15 > Nafion NR50. ZSPSP/ZrO2 exhibited higher ion exchange capacities and selectivity for Fe3+, Co2+, Ni2+ and Cu2+ ions than for other ions.

Remedy of chlorosis induced by iron deficiency in plants with the fungal siderophore rhizoferrin

Although microbial siderophores are characterized by high affinity and selectivity for Fe3+, they are usually less efficient as Fe‐carriers to plants than synthetic chelates. An exception to this is rhizoferrin, a fungal siderophore produced by Rhizopus arrhizus isolated and purified by our group. A ferric complex of rhizoferrin was used in this study as an Fe source for tomato and cucumber ("strategy I") and barley and corn ("strategy II") plants grown in nutrient solutions. The Fe‐rhizoferrin complex was found to be an efficient carrier of Fe to these plants. The efficiency of this chelate is comparable with that of the commonly used ferric complexes of ethylenediaminetetraacetic acid (EDTA) and ethylenediamine‐di(o‐hydroxyphenyl)acetic acid (EDDHA). The application of Fe‐rhizoferrin resulted in enhanced plant weight in barley and corn and higher leaf chlorophyll concentration in tomato, barley and com. Iron uptake by Fe‐stressed cucumber plants from the 59Fe chelate of rhizoferrin and other chelators followed the order: EDDHA > rhizoferrin > EDTA > desferrioxamine B (DFOB); 59Fe translocation from roots to shoots followed the order: rhizoferrin = EDDHA > EDTA > DFOB. The high availability of Fe complexed by rhizoferrin for “strategy I” plants is related to its relatively high redox potential and low affinity to Fe2+. The high availability of Fe‐rhizoferrin to “strategy II” plants is related to its relatively low apparent stability constant with Fe3+, which results in the ability of this compound to transfer Fe3+ via ligand exchange to the phytosiderophores which is specifically taken up by the roots.

Poly-(4- and 5-acrylamidosalicylic acids). Part IV. Selectivity in the extraction of metal cations from aqueous solution

4- and 5-Aminosalicylic acids have been converted into their N-acryloyl derivatives which underwent polymerisation in the presence of sodium and borate ions to give poly-(4- and 5-acrylamidosalicylic acids). These polymers act as solid-state chelating agents capable of selectively extracting specific cations from aqueous solution. Thus the polymers show appreciable selectivity for Fe3+ in the pH range 2·0–2·7, and for Cr3+, UO22+, and Cu2+ in the pH range 4·5–5·5; nearly 100% of each of these ions was extracted when a stoicheiometric quantity of polymer was used. A maximum of ca. 30% of the ions Ni2+, Co2+, Zn2+, and Mn2+ were extracted in the pH range 4·5–6·0. Cd2+ was extracted to ca. 50% in the pH range 4·5–5·5.