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1.
A novel fluoroionophore compound was synthesized from a boron dipyrromethene (BODIPY) fluorophore and 4′-formylbenzo-15-crown-5 ionophore groups. Photophysical properties of the BODIPY-crown compound were studied with UV–Vis and fluorescence spectroscopy. The effect of metalic cations (Li+, Na+, K+, Mg2+, Ca2+, Ba2+, Al3+, Fe3+, Cu2+, Co2+, Zn2+, Ag+, Hg2+, Pb2+) on the absorption and fluorescence spectra of compound 2 was investigated. Blue shifts were detected in UV–Vis spectra upon addition of some metal ions (Al3+ > Fe3+ > Na+). At the same time, the emission intensity of this complex increased due to binding of Na+ ion to the benzo crown cavity. Additionally, a decrease in the intensity of the 630 nm emission peak and an increase in the intensity of the 570 nm emission peak was observed in the fluorescence emission spectra following addition of Al3+ and Fe3+ ions.  相似文献   

2.
A simple and nontoxic fluorescent chemosensor of di‐O‐methyl curcumin has been prepared from curcumin. The sensor exhibited selective and sensitive fluorescent responses toward Al3+ over a wide range of metal ions, such as Mn2+, Ce3+, Pt2+, Sn4+, Hg+, Sb3+, K+, Ca2+, Mg2+, Ba2+, Cu2+, Ni2+, Na+, NH4+, Ag+, Pb2+, Zn2+, Fe2+, Fe3+, Hg2+ and Cr3+ in ethanol/water. The free ligand showed quite weak fluorescence emission due to the isomerization of C?O double bond in the excited state, however, after addition of Al3+, fluorescence emission results in a prominent fluorescence enhancement.  相似文献   

3.
The A1, O, AlO, A12O, Al2O2, WO2, and WO3, partial pressures in the vapor over Al2O3 in a tungsten Knudsen effusion cell between 2300 and 2600 K were derived from A1+, O+, AlO+, A12O+, Al2O2+, WO2+, and WO3+, ion intensities. The mass spectrometer was calibrated against the equilibrium constant of the WO3(g) = WO2(g) + O(g) reaction. Refined values of the ionization cross sections of AlO and A12O2 were used in the partial pressure calculations. The enthalpies of atomization of aluminum suboxides were determined to be Δat H o(AlO, g, 0) = 510.7 ± 3.3 kJ mol−1, Δat H o(Al2O, g, 0) = 1067.2 ± 6.9 kJ mol−1, and Δat H o(Al2O2, g, 0) = 1556.7 ± 9.9 kJ mol−1.  相似文献   

4.
Highly selective all solid state electrochemical sensor based on a synthesized compound i.e. 2‐(1‐(2‐((3‐(2‐hydroxyphenyl)‐1H‐pyrozol‐1‐yl)methyl)benzyl)‐1H‐pyrazol‐3‐yl)phenol (I) as an ionophore has been prepared and investigated for the selective quantification of chromium(III) ions. The effect of various plasticizers, viz. dibutyl phosphonate (DBP), dibutyl(butyl) phosphonate (DBBP), nitrophenyl octyl ether (NPOE), tris‐(2‐ethylhexyl)phosphonate (TEP), tri‐butyl phosphonate (TBP), dioctyl phthalate (DOP), dioctyl sebacate (DOS), benzyl acetate (BA) and acetophenone (AP) along with anion excluders NaTPB (sodium tetraphenyl borate) and KClTPB (potassium(tetrakis‐4‐chlorophenyl)borate was also studied. The optimum composition of the best performing membrane contained (I):KClTPB:NPOE:PVC in the ratio 15 : 3 : 40 : 42 w/w. The sensor exhibited near Nernstian slope of 20.1±0.2 mV/decade of activity in the working concentration range of 1.2×10?7–1.0×10?1 M, and in a pH range of 3.8–4.5. The sensor exhibited a fast response time of 10 s and could be used for about 5 months without any considerable divergence in potentials. The proposed sensor showed very good selectivity over most of the common cations including Na+, Li+, K+, Cu2+, Sr2+, Ni2+, Co2+, Ba2+, Hg2+, Pb2+, Zn2+, Cs+, Mg2+, Cd2+, Al3+, Fe3+and La3+. The activity of Cr(III) ions was successfully determined in the industrial waste samples by using this sensor.  相似文献   

5.
A new Schiff base fluorescence probe, 3-Allylsalicylaldehyde salicylhydrazone (L), for Mg2+ was designed and synthesized. The fluorescence of the sensor L was enhanced remarkably by Mg2+ with 2:1 binding ratio, and the binding constant was determined to be 1.02 × 107 M?1. Probe L had high sensitivity for Mg2+ in a solution of DMF/water (4:1, v/v, pH 7.5), and the detection limit was 4.88 × 10?8 mol/L. Common coexistent metal ions, such as K+, Na+, Ag+, Ca2+, Zn2+, Ba2+, Bi2+, Cu2+, Ni2+, Hg2+, Fe3+ , and Al3+, showed little or no interference on the detection of Mg2+ in solution. The fluorescence probe L, which was successfully used for the determination of trace Mg(II) in real samples, was shown to be promising for liquid-phase extraction coupled with fluorescence spectra.  相似文献   

6.
A conjugated polymer was synthesized by the polymerization of 4,7‐dibromobenzo[2,1,3]thiadiazole ( M‐1 ) with tri{1,4‐diethynyl‐2,5‐bis(2‐(2‐methoxyethoxy)‐ethoxy)}‐benzene ( M‐2 ) via Pd‐catalyzed Sonogashira reaction. The polymer shows strong orange fluorescence. The responsive optical properties of the polymer on various metal ions were investigated through photoluminescence and UV–vis absorption measurements. The polymer displays highly sensitive and selective on‐off Hg2+ fluorescence quenching property in tetrahydrofuran solution in comparison with the other cations including Mg2+, Zn2+, Co2+, Ni2+, Cu2+, Ag+, Cd2+, and Pb2+. More importantly, the fluorescent color of the polymer sensor disappears after addition of Hg2+, which could be easily detected by naked eyes. The results indicate that this kind of polymer sensor incorporating benzo[2,1,3]thiadiazole moiety as a ligand can be used as a novel colorimetric and fluorometric sensor for Hg2+ detection. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011  相似文献   

7.
Meng Q  Zhang X  He C  Zhou P  Su W  Duan C 《Talanta》2011,84(1):53-59
A novel hybrid material (SBA-P1) is prepared through the functionalization of mesoporous silica (SBA-15) with a 1,8-naphthalimide-based dye by sol-gel reaction. The characterization results of elemental analysis (EA), X-ray powder diffractometer (XRD) and spectroscopic methods demonstrate the fluorescence dye P1 is successfully grafted onto the inner surface of SBA-15 and the organized structure is preserved. SBA-P1 can detect Hg2+ with high selectivity to Cu2+, Zn2+, Cd2+, Pb2+, Mn2+, Ni2+, Co2+, Ag+, Cr3+, and Mg2+, Ca2+, Li+, Na+, K+ in water and sensitivity to environmentally relevant mercury in complex natural samples. The quenching fluorescence detection is also reversible by treating with EDTA/base. Furthermore, its fluorescence intensity keeps stable in the physiologically relevant pH range. The extraction ability of SBA-P1 is also estimated by inductively coupled plasma source mass spectrometer (ICP), showing that approximately 90% of the Hg2+ ion is extracted. These results imply that the hybrid material has potential application for sensing and removing of Hg2+ ions in waste water and working as toxicide for acute mercury poisoning.  相似文献   

8.
The retention properties of a SBA-15 mesoporous silica functionalized with –(CH2)3COOH groups, synthesized by a co-condensation route, were investigated for the ion chromatography of different cationic species. A systematic study on the effect of different eluent compositions containing non-complexing (methanesulfonic acid) or complexing (oxalic or pyridine-2,6-dicarboxylic acids) eluents, in the presence of organic modifiers (CH3CN, CH3OH, CH3NH2) on the retention of cations (Li+, Na+, K+, Ca2+, Mg2+, Sr2+, Ba2+, NH4+, Cu2+, Ni2+, Zn2+, Cd2+, Co2+, Pb2+, Fe3+) chosen as model analytes and for their environmental importance, allowed us to elucidate the mechanisms (cation-exchange or complexation) involved in the retention on the SBA-15 phase. For the first time separations of cations on SBA-15 based stationary phases are investigated, providing the basis for further development of mesoporous silica chemistry for in-flow ion-exchange applications.  相似文献   

9.
Covalent organic frameworks (COFs) have been widely applied in gas capture and separation, but the fluorescent property of COFs with large π-conjugated system tends to be underexplored. Here we report the fluorescent properties of several COFs including TaTa, DhaTab, TRITER-1 and TzDa and the effect of metal ions of Na+, Mg2+, K+, Ca2+, Cu2+, Zn2+, Pb2+, Ag+, Cd2+ and Fe3+ on the fluorescence of these COFs. The results show that only Fe3+ significantly quenched the fluorescence of the studied COFs. The possibility of the four COFs for selective sensing of Fe3+ was demonstrated. The possible mechanism of the effect of Fe3+ on the fluorescence of the COFs was based on the absorption competition quenching.  相似文献   

10.
A rhodamine‐based colorimetric and fluorescent pH chemosensor ( RhA ) was designed and synthesized via a coupling reaction between rhodamine ethylenediamine and succinic anhydride. RhA showed excellent pH response in aqueous solutions. In addition, common cations (Na+, K+, Ag+, Mg2+, Ca2+, Pb2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+, Al3+, Cr3+, Fe3+, Au3+, Pt2+, and Ru2+) did not interfere with the pH response. As it has the potential to be used as a portable pH sensor, RhA was immobilized on activated cellulose paper using N,N'‐dicyclohexylcarbodiimide (DCC) and N,N'‐dimethylpyridin‐4‐amine (DMAP) as the coupling reagent to obtain a composite pH sensor ( CP‐RhA ). CP‐RhA was characterized by ATR‐FTIR, UV–vis, and fluorescence spectroscopy, and by scanning electron microscopy (SEM). CP‐RhA showed a rapid response in the pH range 1–8 through color and fluorescence changes. DFT calculations showed a blue‐shifted spectrum in the protonated form compared to the neutral form. Moreover, the pH sensor paper could be reused by dipping in NaOH. Thus, our work demonstrates the potential of the rhodamine dye composite for visualizing pH changes in real systems.  相似文献   

11.
The structural and electrochemical effects of electrospun V2O5 with selected redox-inactive dopants (namely Na+, Ba2+ and Al3+) have been studied. The electrospun materials have been characterised via a range of analytical methods including X-ray diffraction, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller surface area measurements and scanning and transmission electron microscopy. The incorporation of dopants in V2O5 was further studied with computational modelling. Structural analysis suggested that the dopants had been incorporated into the V2O5 structure with changes in crystal orientation and particle size, and variations in the V4+ concentration. Electrochemical investigations using potentiodynamic, galvanostatic and impedance spectroscopy analysis showed that electrochemical performance might be dependent on V4+ concentration, which influenced electronic conductivity. Na+- or Ba2+-doped V2O5 offered improved conductivities and lithium ion diffusion properties, whilst Al3+ doping was shown to be detrimental to these properties. The energetics of dopant incorporation, calculated using atomistic simulations, indicated that Na+ and Ba2+ occupy interstitial positions in the interlayer space, whilst Al3+ is incorporated in V sites and replaces a vanadyl-like (VO)3+ group. Overall, the mode of incorporation of the dopants affects the concentration of oxygen vacancies and V4+ ions in the compounds, and in turn their electrochemical performance.
Graphical abstract ?
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12.
A fluorescent chemosensor ( 1 ) based on 2‐hydroxy‐1‐naphthaldehyde Schiff‐base was developed for the detection of Al3+ in 100% aqueous solution. Upon addition of Al3+, a significant fluorescence enhancement was observed, which was not affected by other metal ions including Na+, K+, Ca2+, Mg2+, Mn2+, Co2+, Ni2+, Cu2+, Cr3+, Ag+, Pb2+, Zn2+, Cd2+, Hg2+, Fe2+ and Fe3+ under weak acid conditions. Moreover, the specific response to Al3+ was visible under natural light. The binding mode between 1 and Al3+ was clarified by ESI‐MS and 1H NMR.  相似文献   

13.
Er3+-doped Al2O3 nanopowders have been prepared by the non-aqueous sol-gel method using the aluminum isopropoxide as precursor, acetylacetone as a chelating agent, nitric acid as a catalyzer, and hydrated erbium nitrate as a dopant under isopropanol environment. The different phase structure, including three crystalline types of (Al, Er)2O3 phases, α, γ, θ, and an Er–Al–O stoichiometric compound phase, Al10Er6O24, was observed for the 0.01–0.5 mol% Er3+-doped Al2O3 nanopowders at the sintering temperature of 1,000 °C. The green and red up-conversion emissions centered at about 523, 545 and 660 nm, corresponding respectively to the 2H11/2, 4S3/24I15/2 and 4F9/24I15/2 transitions of Er3+, were detected by a 978 nm semiconductor laser diodes excitation. With increasing Er3+ doping concentration from 0.01 to 0.1 mol%, the intensity of the green and red emissions increased with a decrease of the intensity ratio of the green to red emission. When the Er3+ doping concentration rose to 5 mol%, the intensity of the green and red emissions decreased with an increase of their intensity ratio. The maximum intensity of both the green and red emissions with the minimum of intensity ratio was obtained, respectively, for the 0.1 mol% Er3+-doped Al2O3 nanopowders composed of a single α-(Al,Er)2O3 phase. The intensity ratio of the green emission at 523 and 545 nm increased monotonously for all Er3+ doping concentrations. The two-photon absorption up-conversion process was involved in the green and red up-conversion emissions of the Er3+-doped Al2O3 nanopowders.  相似文献   

14.
A novel AB type of clickable monomer, (S)‐2‐[(2‐azido‐1‐phenylethylimino)methyl]‐5‐propargyloxyphenol (AMPP) was designed and polymerized to yield a class of main‐chain chiral poly(imine‐triazole)s through the metal‐free click reaction. With the thermally induced polymerization, the desired polytriazoles can be easily prepared in high yields by a stepwise heating‐up process and have the number‐average molecular masses ranging from 5.1 × 103 to 58.1 × 103 (polydispersity indices = 1.38?1.68). The polymers were characterized by Fourier Transform Infrared spectroscopy (FTIR), 1H Nuclear Magnetic Resonance (NMR), and gel permeation chromatography, and their optical properties were studied by fluorescence and circular dichroism (CD) spectroscopies. As a chemosensor, these polymers exhibited a selective “turn‐on” fluorescence enhancement response toward Zn2+ ion over other cations such as Na+, K+, Mg2+, Ca2+, Ag+, Pb2+, Cd2+, Hg2+, Mn2+, and Ni2+ in dimethyl sulfoxide. However, the Zn2+‐induced fluorescence signal was subject to serious interference by Al3+, Cu2+, Cr3+, and Fe3+ ions. Interestingly, the chiral polymer showed distinctive changes in the CD spectra on complexation with Zn2+, which allowed for the discrimination of this ion in the presence of other species tested including those interfering ions observed in the fluorescent detection. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2248–2257  相似文献   

15.
《Analytical letters》2012,45(11):1467-1484
Natural zeolite clinoptilolite was successfully applied in the sensing technology for electrochemical detection of ammonium. A novel ammonium-selective sensor was developed based on clinoptilolite, possessing intrinsic ammonium-sieving and ion exchange capacity. The sensor design allowed measurements in both differential mode and requiring no classical reference electrode. The sensor selectivity towards Na+, K+, Ca2+, Mg2+, and Al3+ was studied. The limit of detection and the dynamic range of the ammonium-selective conductometric microsensor, determined in the phosphate buffer solution, were 1.0 × 10?8 M and 0–8 mM, respectively. The ammonium sensor presented high operational and storage stability.  相似文献   

16.
As an important metal element, aluminium has a significant impact on the environment and human health, and thus the detection of Al3+ has become the subject of much research. We synthesized a Ni(II)‐based metal–organic gel (Ni‐MOG), which can serve as an Al3+ fluorescence sensor with high selectivity and sensitivity, the limit of detection being calculated to be 0.5 μM. In addition, a composite film was further fabricated by hybridization of this Ni‐MOG with poly(vinyl alcohol). The composite film produced a rapid fluorescence response to Al3+ solutions at concentrations above 5 × 10?5 M in 5 min. The Ni‐MOG composite film can also be successfully applied for the sensitive detection of Al3+ in real samples of tap water and seawater. The effective detection of Al3+ described in this contribution provides a new insight into water quality monitoring and has promising application value.  相似文献   

17.
Two linear 1,4-distyrylbenzenes and five star-shaped 1,3,5-tristyrylbenzene derivatives ( L2a and L2b , Y0–Y3 and YNBu ) were synthesized and spectroscopically characterized. The photophysical properties, optical response to acid and metal ions were investigated. Upon backbone extension of linear distyrylbenzenes or the introduction of dibutylanilines, the electronic spectra are redshifted. Incorporation of electron-deficient pyridyl units does not significantly affect the optical properties. Variation of the number of pyridine rings and substitution pattern tune the fluorescence response to acids and metal ions. The novel arenes discriminate Al3+, Mn2+, Fe3+, Fe2+, Cd2+, Ag+ and Hg2+.  相似文献   

18.
The Ru-Cs+/MgO and Ru-Cs+/γ-Al2O3 catalysts, which were prepared by an impregnation method using RuOHCl3 and Cs2CO3 as precursor compounds and reduced with H2 at 450°C, are characterized by X-ray diffraction, high-resolution transmission electron microscopy (with X-ray microanalysis), and X-ray photoelectron spectroscopy (XPS). The Cs+/MgO(Al2O3) systems, Ru-Cs+ black, and model systems prepared by cesium sputtering onto polycrystalline ruthenium foil are studied as reference samples. It is found that, in the Ru-Cs+/MgO sample, cesium is present as a Cs2 + xO cesium suboxide, which weakly interacts with the support, localized on the surface of Ru particles or near them. In the case of Ru-Cs+/γ-Al2O3, cesium occurs as a species that is tightly bound to the support; this is likely surface cesium aluminate, which prevents promoter migration to Ru particles. The Ru-Cs+/MgO sample exhibits a considerable shift of the Ru3d line in the XPS spectra toward lower binding energies, as compared to the bulk metal. It is hypothesized that this shift is due to a decrease in the electron work function from the surface of ruthenium because of the polarizing effect of Cs+ ions in contact with Ru particles. Based on the experimental results, the great difference between the catalytic activities of the Ru-Cs+/MgO and Ru-Cs+/γ-Al2O3 systems in ammonia synthesis at 250–400°C and atmospheric pressure is explained.  相似文献   

19.
Nanostructured polypyrrole (PPy) film doped with Tiron was electrodeposited from aqueous solution on the surface of transparent electrode and used for sensitive, selective and rapid electrically controlled fluorescence detection of Fe3+ in aqueous media. The fluorescence intensity of PPy-Tiron film decreases linearly in the presence of Fe3+ by applying negative potential over a concentration range from 5.0 × 10−8 to 1.0 × 10−6 mol L−1, with a relatively fast response time of less than 30 s at pH 7.4. The detection is not affected by the coexistence of other competitive metal ions such as Al3+, Ce3+, Tl3+, La3+, Bi3+, Cr2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+, Pb2+, Na+, K+, Mg2+, Ca2+, Sr2+ and Ba2+. The proposed electro-fluorescence sensor has a potential application to the determination of Fe3+ in environmental and biological systems. The fluorescent thin film sensor was also used as a novel probe for Fe3+/Fe2+ speciation in aqueous solution.  相似文献   

20.
A luminescent cadmium–pamoate metal–organic framework, [Cd2(PAM)2(dpe)2(H2O)2]?0.5(dpe) ( 1 ), has been synthesized under hydrothermal conditions by using π‐electron‐rich ligands 4,4′‐methylenebis(3‐hydroxy‐2‐naphthalenecarboxylic acid) (H2PAM) and 1,2‐di(4‐pyridyl)ethylene (dpe). Its structure is composed of both mononuclear and dinuclear CdII building units, which are linked by the PAM and dpe ligands, resulting in a (4,8)‐connected 3D framework. The π‐conjugated dpe guests are located in a 1D channel of 1 . The strong emission of 1 could be quenched efficiently by trace amounts of 2,4,6‐trinitrophenol (TNP), even in the presence of other competing analogues such as 4‐nitrophenol, 2,6‐dinitrotoluene, 2,4‐dinitrotoluene, nitrobenzene, 1,3‐dinitrobenzene, hydroquinone, dimethylbenzene, and bromobenzene. The high sensitivity and selectivity of the fluorescence response of 1 to TNP shows that this framework could be used as an excellent sensor for identifying and quantifying TNP. In the same manner, 1 also exhibits superior selectivity and sensitivity towards Cu2+ compared with other metal ions such as Zn2+, Mn2+, Mg2+, K+, Na+, Ni2+, Co2+, and Ca2+. This is the first MOF that can serve as a dual functional fluorescent sensor for selectively detecting trace amounts of TNP and Cu2+.  相似文献   

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