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1.
A new series of azobenzene dyes, which possessed colorimetric and ratiometric recognition to Hg 2+ based on the mechanism of internal charge transfer (ICT), was developed and characterized. The molecules involving azo and imino functional groups can coordinate with Hg 2+ to result in a large blue shift from 453 to 363 nm corresponding to a notable color change from orange to pale yellow in aqueous methanol solution (H 2O/CH 3OH=1/4, V/ V), which can be applied to naked eye detection of Hg 2+. The sensitivity, selectivity and binding mode of the sensors to Hg 2+ were investigated by UV‐Vis spectroscopy. 相似文献
2.
A gold(I) complex that exhibited aggregation‐induced emission in acetonitrile‐water mixtures was designed. It showed high selectivity and sensitivity for Hg 2+ in acetonitrile‐H 2O (1:1, V: V) solution. Dynamic light scattering measurements were conducted to verify that the addition of Hg 2+ changed the particle size and induced fluorescence quenching. 相似文献
3.
In this article, a novel “off–on” fluorescent probe 2-(pyren-1-ylmethylene)-1 H-indene-1,3(2 H)-dione ( PID ) for Hg 2+ was designed and synthesized. The selectivity, concentration titration, pH titration, time dependence, limit of detection, and recognition mechanism of PID for Hg 2+ in CH 3CH 2OH/H 2O solution were also investigated. The results indicated that PID exhibited high selectivity, sensitivity, and fast response to Hg 2+, and the limit of detection was as low as 20.7 nmol/L. In addition, PID could work in a wide pH range, and the determination of Hg 2+ in water samples showed that it could be used as a potential detection tool in practical application. 相似文献
4.
In this work, we reported a simple coumarin-boronic acid ester fluorescent probe 1 , which displayed very high “ON-OFF” fluorescence response for Hg 2+ in an aqueous environment (H 2O/CH 3CN = 1:1, v/v) or in a PBS solution (pH = 7.4). With the addition of Hg 2+ to the solution of probe, a color change from light yellow to orange could be observed by naked eye. The detection limits were lower than the permitted level of Hg 2+ in drinking water defined by WHO. Infrared spectroscopy, mass spectroscopy and 1H NMR titration studies showed that probe 1 formed a 1:1 complex with Hg 2+. In addition, the probe was non-toxic to cells and could stain specifically the membrane region surrounding the HeLa cell. 相似文献
5.
The AuRe nanoalloy particles in molar ratio of 9:1 were prepared by sodium borohydride procedure, and modified by single strand DNA (ssDNA) to prepare an aptamer AuRe nanoprobe (AuRessDNA) for Hg 2+. In the pH 7.0 Na 2HPO 4‐NaH 2PO 4 buffer solution and in the presence of NaCl, Hg 2+ interacted with AuRessDNA to form double‐stranded T‐Hg 2+‐T mismatched and release AuRe nanoparticles that aggregate to large AuRe nanoparticles clusters causing the resonance scattering (RS) peak red shifting and the RS intensity enhanced linearly. On those grounds, 0.067–33.3 nmol·L ?1 Hg 2+ can be detected rapidly by the aptamer‐modified AuRe nanoparticles RS assay, with a detection limit of 0.04 nmol·L ?1 Hg 2+. If the aggregated AuRe particles were removed by membrane filtration, the excess AuRessDNA in the filtration solution exhibits catalytic effect on the new Te particle reaction between Na 2TeO 4 and SnCl 2. As the concentration of Hg 2+ increased, the AuRessDNA nanoparticles in the filtrate solution decreased, the RS intensity at 734 nm decreased linearly. The Hg 2+ concentration ( c) in the range of 0.00133–0.267 nmol·L ?1 was linear to the decreased RS intensity (Δ I734nm), with a regression equation of Δ I= ?786.4 c?4.4, a correlation coefficient of 0.9975, and a detection limit of 0.9 pmol·L ?1 Hg 2+. This method was applied to the detection of Hg 2+ in water samples, with satisfactory results. 相似文献
6.
A series of isomorphic lanthanide metal–organic frameworks (MOFs) Ln(TATAB)?(DMF) 4(H 2O)(MeOH) 0.5 (LnTATAB, Ln=Eu, Tb, Sm, Dy, Gd; H 3TATAB=4,4′,4′′‐s‐triazine‐1,3,5‐triyltri‐ p‐aminobenzoic acid) have been solvothermally synthesized and structurally characterized. Among these MOFs, TbTATAB exhibits good water stability and a high fluorescence quantum yield. Because mercury ions (Hg 2+) have a high affinity to nitrogen atoms, and the space between multiple nitrogen atoms from triazine and imino groups is suitable for interacting with Hg 2+ ions, TbTATAB shows highly selective and sensitive detection of Hg 2+ in aqueous solution with a detection limit of 4.4 nm . Furthermore, it was successfully applied to detect Hg 2+ ions in natural water samples. 相似文献
7.
This paper employs a specially designed aggregation‐induced emission fluorogen (AIEgen) to in vivo visualize the process of Hg 2+ bioaccumulation in a common species of freshwater zooplankton Daphnia carinata ( D. carinata) by two methods, direct Hg 2+ absorption and ingestion of Hg 2+ contaminated food. We analysed the relevance between photoluminescence (PL, I 595/I 480) ratios and Hg 2+ (C Hg2+) and developed the master curve for Hg 2+ determination based on measuring the PL intensity of the solution. Meanwhile, fluorescent image analysis showed that the major recipient organs of Hg 2+ in D. carinata were the compound eyes and carapace, followed by the intestine and shell gland, but not the brain or heart. The response of D. carinata to Hg 2+ via uptake from surrounding water differed distinctly from that through food intake of the algae ( Euglena gracilis) contaminated by mercury. When Hg 2+ was encapsulated by algae membrane, no fluorescence was detected, and the carapace morphology remained intact after ingesting algae for 80 min, in contrast to the rapid carapace deformation by direct Hg 2+ absorption. The D. carinata showed higher mortality by direct Hg 2+ immersion than via food ingestion. The reason for the high mortality after Hg 2+ immersion was possibly due to carapace deformity after chemical reaction between chitin and mercury, but the biochemical pathway leading to morality needs further study. 相似文献
8.
The present work reports the synthesis, characterization, and antimicrobial activities of adipic acid-capped silver nanoparticles (AgNPs@AA) and their utilization for selective detection of Hg 2+ ions in an aqueous solution. The AgNPs were synthesized by the reduction of Ag + ions with NaBH 4 followed by capping with adipic acid. Characterization of as-synthesized AgNPs@AA was carried out by different techniques, including UV–Visible spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Dynamic Light Scattering (DLS), and zeta potential (ZP). In the UV–Vis absorption spectrum, the characteristic absorption band for AgNPs was observed at 404 nm. The hydrodynamic size of as-synthesized AgNPs was found to be 30 ± 5.0 nm. ZP values (−35.5 ± 2.4 mV) showed that NPs possessed a negative charge due to carboxylate ions and were electrostatically stabilized. The AgNPs show potential antimicrobial activity against clinically isolated pathogens. These AgNPs were found to be selectively interacting with Hg 2+ in an aqueous solution at various concentrations. A calibration curve was constructed by plotting concentration as abscissa and absorbance ratio (A Control − A Hg/A Control) as ordinate. The linear range and limit of detection (LOD) of Hg 2+ were 0.6–1.6 μM and 0.12 μM, respectively. A rapid response time of 4 min was found for the detection of Hg 2+ by the nano-probe. The effect of pH and temperature on the detection of Hg 2+ was also investigated. The nano-probe was successfully applied for the detection of Hg 2+ from tap and river water 相似文献
9.
The matrix model was used to analyze the distribution diagrams and formation functions of ammonia complexes [M(NH 3)
n
] 2+ ( n = 0−4) of Group II metal ions (Mg 2+, Ca 2+, Zn 2+, Cd 2+, and Hg 2+) in solution. Intrinsic binding constants of the ligand ( K
in) and mutual influence corrections (ω) for complex formation with aqua ions in solution were calculated. The equilibrium constants
were calculated by the matrix method. The coordination sphere of Mg 2+, Ca 2+, and Zn 2+ by ammonia in a cooperative manner; with Cd 2+ and Hg 2+, both cooperative and anticooperative binding occur concurrently. Possibilities for differentiation between tetrahedral and
square planar coordination polyhedra on the basis of the characteristic features of ligand binding, determined by the matrix
model, are discussed. 相似文献
10.
E. M. F. of the Cell, Cd-Hg (2-phase)/CdAc 2( m), Hg 2Ac 2( s)/Hg was measured at 20°, 25°, 30° and 40°C. The standard e. m. f. of the cell, Cd/CdAc 3( m), Hg 2Ac 2( c)/Hg was evaluated as E°=1.1500?11.09×10 ?4T+1.06×10 ?8T 2 The thermodynamic data of the reaction, Cd( c) + Hg 2Ac 2( c)=2Hg( l)+Cd ++( aq)+2Ac ?( aq) at 25°C were estimated as ΔF°=?42,139, ΔH°=?48,698 cal mole ?1 and ΔS°=?22.0 cal deg ?1 mole ?1 at 25°C. The thermodynamic data for the formation of Hg 2Ac 2( s) were evaluated as ΔF f°=?202.3, ΔH f°=?154.5 Kcal mole ?1 and S°=72.9 cal deg ?1 mole ?1. From measurements of the heats of solution of CdAc 2·2H 2O in aqueous solution, the relative partial molal enthalpies of cadmium acetate in aqueous solution were estimated. 相似文献
11.
A new solid substrate room temperature phosphorimetry (SSRTP) for the determination of trace mercury has been established, using Triton X‐100 as a sensitizer. The regression equation of working curve was Δ Ip=11.40 m(Hg 2+)+1.569 (ag·spot ?1, n=6, Δ Ip= Ip1? Ip2, Ip1 and Ip2 referred to the phosphorescence intensity of the blank reagent and the test solution, respectively), and correlation coefficient ( r) was 0.9984. The RSD valus of the determination of 0.016 and 8.0 ag·spot ?1 Hg 2+ were 4.1% and 1.7% ( n=8), respectively, indicating that the method had good repeatability. The limit of detection (LOD) calculated by 3Sb/ k was 7.0 zg·spot ?1 Hg 2+ (corresponding concentration: 1.8×10 ?17 g·mL ?1, Sb=0.025, n=11). This method has high sensitivity, selectivity and precision, which was applied to determination of trace mercury in water samples with the result being agreed very well with that of dithizone extraction spectrophotometry. 相似文献
12.
A series of new pyridine-urea oligomers were synthesized and tested for their ability to recognize ions in PBS or Ac buffer solution by fluorescence. The results showed that the ability of oligourea urea to selectively recognize Hg 2+ was gradually enhanced with the increase of chain, which was further proved by DFT calculation. The 1:2 stoichiometry was established for the L7-Hg 2+ complex on the basis of Job's plot. The binding constant ( KB) and the lowest detection limit for Hg 2+ were also determined. DFT calculations were used to optimize the structures of L2-7 and its Hg 2+ complexes. Highly sensitive and selective probes for the recognition of Hg 2+ based on this report are expected to be developed and used for in vivo detection. 相似文献
13.
The phase and chemical composition of precipitates formed in Mg(VO 3) 2-VOSO4-H 2O system at initial pH from 1 to 7 and temperature from 80 to 90°C was studied. Polyvanadates of variable composition Mg
x
V
y
4+V 12-y
5+1O 31–δ · nH 2O (0.7 ≤ x ≤ 1.3, 1.2 ≤ y ≤ 2.4, 0.7 ≤ δ = 1.4) were formed at pH from 1 to 4 and V 4+/V 5+ ratio from 0.43 to 9. Compounds with the general formula Mg
x
V
y
4+V 6-y
5+O 16-δ · nH 2O (0.7 ≤ x ≤ 0.65, y = 1.0, 0.8 ≤ δ ≤ 0.85) were formed at pH from 6.0 to 7.0 and V 4+/V 5+ ratios from 0.11 to 0.25. The maximum V 4+ concentration ( y = 2.4) in the precipitates was achieved at the VV 4+/V 5+ solution ratio of 1.0 and pH = 3. The precipitates in solutions with pH 3 were formed only upon addition of VO 2+ ions with the maximum rate at a V 4+/V 5+ ratio of 0.33. These processes were limited by second-order reactions on the surface of polyvanadates. 相似文献
14.
汞离子(Hg~(2+))由于高毒性以及容易对环境和人体造成损害,其检测越来越受到人们的重视。本文基于4-(二乙氨基)水杨醛设计合成了一种近红外发射荧光探针L,该探针可在MeCN/HEPES(体积比2/8,pH=7.4)缓冲溶液中高选择性地荧光增强识别Hg~(2+),其具有合成简便、抗干扰能力强、适用pH范围宽等特点。进一步研究表明,探针L可用于真实水样中Hg~(2+)的检测。 相似文献
15.
A new rhodamine-based Hg 2+-selective fluorescent probe ( I) was designed and synthesized. Compound I displays excellent selective and sensitive response to Hg 2+ over other transition metal ions in neutral aqueous solutions. I itself is a colorless, nonfluorescent compound. Upon addition of Hg 2+ to its solution, the thiosemicarbazide moiety of I undergoes an irreversible desulfurization reaction to form the corresponding 1,3,4-oxadiazole ( II), a colorful and fluorescent product, causing instantaneous development of visible color and strong fluorescence emission.
Based on this mechanism, a fluorogenic probe for Hg 2+ was developed. The fluorescence increases linearly with the Hg 2+ concentration up to 0.8 μmol L −1 with the detection limit of 9.4 nmol L − (3 σ). 相似文献
16.
In this work, four POM-based compounds containing viologen ligands were synthesized, namely {Cu II(tybipy) 2(DMF) 2[H 2( β-Mo 8O 26)] 2} ⋅ 4 C 2H 7N ( 1 ), (Htybipy) 2 ⋅ ( β-Mo 8O 26) ( 2 ) (tybipy⋅Br=1-Thiophen-3-ylmethyl-[4,4’]bipyridinyl-1-ium bromide), [Cu II(nibipy) 2(4,4’-bipy)] ⋅ (SiW 12O 40) ( 3 ), (Hnibipy) 2 ⋅ ( δ-Mo 8O 26) ( 4 ) (nibipy⋅Cl=1-(4-Nitro-benzyl)-[4,4’]bipyridinyl-1-ium chloride, 4,4’-bipy=4,4’-bipyridine). In compounds 1 and 3 , Cu 2+ and mixed organic ligands modify POM anions. On the other hand, 2 and 4 are supramolecular structures only containing ligands and anions. Under Xe lamp with filter (300-400 nm) irradiation, these four compounds showed good photoresponse and photochromic ability, which can be used in mixed matrix films for visible UV detectors. Compounds 1 – 4 also have photoluminescence property and show good fluorescence quenching effect. A suspension of four compounds can be evenly spread on filter paper as inkless and erasable printing materials. Compounds 1 and 2 were also used as Hg 2+ fluorescence detectors. The fluorescence intensity of 1 decreased by ca. 90 % when the concentration of Hg 2+ increased to 40 mM. Moreover, we also prepared composites 1 / 2 @Hg 2+, 1 @Cu 2+, 1 @Co 2+ by introducing 1 / 2 and Hg 2+, Cu 2+ and Co 2+ to detection paper respectively, which can act as photochromic materials with features of fast color recovery. 相似文献
17.
A new, highly sensitive probe L2 for the selective detection of Hg 2+ in organo-aqueous (H 2O:CH 3CN, 1:1, v/v, HEPES buffer, pH 7.2) medium has been synthesized from rhodamine 6G-hydrazide and 4-nitroindole-3-carboxaldehyde. It was thoroughly characterized by physicochemical techniques including single crystal X-ray diffraction studies. The reaction of L2 with Hg 2+ gives a 1:1 stoichiometry resulting in a 146 fold fluorescence enhancement and a binding constant ( Kf) of 3?×?10 4 M ?1. The spirolactam form of the probe is non-fluorescent; however, it shows dual channel (absorbance and fluorescence) recognition of Hg 2+ via CHEF effect through the opening of the spirolactam ring. The quantum yields of L2 (0.00045) and L2-Hg 2+ (0.29) show the higher stability of complex in the excited state over the free ligand. The 44.5?nM LOD value demonstrates the detection of Hg 2+ at a very low concentration range. Cell imaging studies show the cytoplasmic recognition of Hg 2+ by L2. Experimental results are comparable with theoretical values obtained by DFT studies. The fluorescence emission of the complex was completely quenched by I - and from the reversibility studies an advance level INHIBIT logic gate and memory device can be framed. 相似文献
18.
The interaction between mercuric ion and apoCopC in the absence or presence of cupric ion was investigated through difference UV spectra in Hepes buffer (10 mmol·L^-1) at pH 7.4. The results suggest that mercuric ion can bind to C- and N-terminal binding sites of apoCopC, and the conditional binding constants were calculated to be kN=(6.79± 1.12)× 10^6 mol^-1·L and kc=(3.06±0.05)× 10^5 mol^-1·L. Using urea as a chemical agent, the conformational stabilities of apoCopC and HgN^2+ -CopC-Hgc^2+ were monitored by fluorescence spectrum in Hepes buffer (50 mmol·L^-1) at pH 7.4. The free energy of stabilization is (14.69±0.85) and (16.66±0.55) kJ.mol^-1, respectively. HgN^2+ -CopC-Hgc^2+ is more stable than apoCopC. 相似文献
19.
The 4-acetylamino-1,8-naphthalimide derivative containing the N-phenylazadithia-15-crown-5-ether fragment in the N-aryl substituent at the imide nitrogen atom of the naphthalimide core was synthesized, and its cation-dependent spectral properties were studied. The resulting compound in the photoexcited state exhibits low-intensity fluorescence due to the process of electron transfer from the N-aryl group to the naphthalimide residue, which is confirmed by the data of quantum chemical calculations performed using the PM6 method. The binding of Hg2+ in an aqueous acetate buffer solution at pH 6.0 is accompanied by the formation of a 1: 1 metal—ligand complex in which the electron transfer is suppressed leading to fluorescence enhancement. The observed spectral changes were used for the determination of the stability constant K of the complex (logK = 6.51±0.03). The found limit of Hg2+ detection using the synthesized sensor (28 nmol L?1) is fairly close the maximum permissible concentration for mercury in drinking water. The study of the selectivity of complexation showed that the presence of Cu2+, Zn2+, Ni2+, Pb2+ Cd2+, Ca2+, Mg2+, and Fe2+ cations did not impede the determination of Hg2+. The presented results indicate that the synthesized chemosensor is promising as a selective and highly sensitive fluorescent reagent for Hg2+ ions in an aqueous solution. 相似文献
20.
A new receptor 3-((2-(1H-benzo[ d]imidazol-2-yl)phenylimino)methyl)benzene-1,2-diol ( 1) was synthesised and developed as a highly selective fluorescent chemosensor for the detection of Hg 2+ in semi-aqueous media. The fluorescence of receptor 1 was dramatically and selectively quenched on complexation with Hg 2+ ion with the detection limit down to 0.20 μM. The developed sensor was successfully applied for the determination of Hg 2+ content in water samples. Density Functional Theory (DFT) calculations were performed to study the mechanistic behaviour behind the binding of Hg 2+ with receptor 1. 相似文献
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