共查询到20条相似文献,搜索用时 734 毫秒
1.
Qiuping Hu Yuling Liu Zhengqiang Li Rongzheng Wen Yuan Gao Yiling Bei Qingzeng Zhu 《Tetrahedron letters》2014
A new rhodamine B derivative bearing a hydrazone group has been designed and prepared. The synthesized colorimetric and fluorescent molecular chemosensor can be used as a dual probe, selectively detecting Al3+ and Cu2+ in acetonitrile solution by monitoring changes in the absorption and fluorescence spectral patterns. The results show that Al3+ ions can induce a greater fluorescence enhancement, while the addition of Cu2+ ions induces a strong UV–vis absorption enhancement with weak fluorescence. The limits of detection of Cu2+ and Al3+ were estimated to be 2.9 × 10−7 M and 8.3 × 10−9 M, respectively. 相似文献
2.
Zhiyong Xing Junli Wang Junhui Huang Xiangfeng Chen Ziao Zong Chuanbin Fan Guimei Huang 《Molecules (Basel, Switzerland)》2022,27(8)
An easy prepared probe, BHMMP, was designed and synthesized, which displayed a significant fluorescence enhancement (over 38-fold) and obvious color change in the recognition of Al3+. The binding ratio of probe BHMMP to Al3+ was determined as 1:1, according to Job plot. The binding mechanism was fully clarified by the experiments, such as FT-IR spectrum, ESI–MS analysis, and 1H NMR titration. A DFT study further confirmed the binding mode of BHMMP to Al3+. The limit of detection (LOD) for Al3+ was determined as low as 0.70 µM, based on the fluorescence titration of BHMMP. Moreover, the results from real sample experiments, including real water samples, test papers, and cell images, well-demonstrated that BHMMP was capable of sensing Al3+ in environmental and biological systems. 相似文献
3.
Subhendu Mondal 《Supramolecular chemistry》2013,25(10):645-652
ABSTRACTPerimedine labelled rhodamine dye 1 has been designed and synthesised. Metal ion binding studies of 1 have been performed in CH3CN/H2O (3:1, v/v, 10 mM Tris-HCl buffer, pH = 6.90). Compound 1 senses multiple metal ions such as Al3+, Fe3+ and Fe2+ by exhibiting turn on fluorescence and colour change (colourless to pink) under different experimental conditions. Concentration variation distinguishes Al3+ from Fe3+ ion. At low concentration (c = 1 x 10?4 M), only Al3+ ion can exhibit turn on fluorescence with sharp colour change. Sensing of Fe2+ ion through turn on fluorescence and colour change has been possible via in situ oxidation by following Fenton’s reaction. 相似文献
4.
In this work, we synthesised and characterised three novel fluorescence macrocyclic sensors containing optically active dansyl groups. The studies for the interaction of the synthesised compounds with various mental ions (Li+, Na+, K+, Ag+, Mg2+, Ca2+, Ba2+, Pb2+, Zn2+, Co2+, Cd2+, Hg2+, Ni2+, Cu2+, Mn2+, Cr3+, Al3+, Fe3+) were performed by fluorescence titration, Job’s plot, ESI-MS and DFT calculations. The results showed that the sensors 1a–1c displayed selective recognition for Cu2+ and Fe3+ ions and formed stoichiometry 1:1 complex through PET mechanism in DMSO/H2O solution (1:1, v/v, pH 7.4 of HEPES). The binding constant (K) and detection limit were calculated. 相似文献
5.
Aasif Helal Hyun Gon Kim Manik Kumer Ghosh Cheol-Ho Choi Sung-Hong Kim Hong-Seok Kim 《Tetrahedron》2013
Two new reactive and highly selective turn-on fluorescent chemosensors based on the position of ring annulation of the naphthalene–thiazole moiety for aluminum ions in ethanol, were synthesized and investigated. It was found that sensors 2 and 4 exhibited a remarkable enhancement of emission upon complexation with Al3+. A TD-B3LYP/6-31G(d,p) calculation was performed to characterize the nature of the fluorescence behavior of sensors 2 and 4 upon Al3+ complexation. The mechanism of fluorescence was based on the cation promoted hydrolysis of ester and subsequent complexation. The combination of experimental and computational analyses provides a more complete understanding of the molecular level origin of these types of unique photophysical properties. 相似文献
6.
Yanling Xu Zhenni Zhao Rui Wang Yuemei Li Wei Zheng Zhirong Zhang 《Analytical letters》2018,51(13):2085-2098
12CaO?·?7Al2O3 doped with lanthanide is characterized by remarkable and technologically important up-conversion emission. However, the low up-conversion efficiency still remains the main limitation for practical applications. To improve the efficiency, bivalent alkaline earth ions (Mg2+, Sr2+, Ba2+)-tridoped Tm3+/Yb3+/12CaO?·?7Al2O3 were synthesized through a high-temperature solid-state reaction. The up-conversion luminescence properties of the samples were investigated by X-ray diffraction, fluorescence spectral measurement pump power, and fluorescence decay curves. The luminescence intensity of samples was significantly enhanced by bivalent alkaline earth ions. 12CaO?·?7Al2O3 doped with Sr2+ ions has stronger effects on up-conversion enhancement, which is better than Mg2+ and Ba2+. The up-conversion emission intensity was enhanced by 318 times and the red emission intensity by 218 times with 10?mol% Sr2+ ion. Additionally, the blue and red up-conversion emission peaks at 475 and 650?nm corresponding to energy transitions of 1G4 → 3H6 and 1G4 → 3F4, 3F2 → 3H6 were characterized using steady-state rate equations. 相似文献
7.
用分子生物学方法表达、纯化了游仆虫中心蛋白及N-端半分子,用铽荧光探针法、离子竞争法研究了pH 7.4,0.01 mol·
L-1 Hepes条件下中心蛋白与铽、钙的结合性质。结果表明中心蛋白有4个铽结合部位,其中2个为高亲合结合部位、2个为低亲合结合部位。具有2个低亲合结合部位的中心蛋白半分子与铽结合的条件常数是(2.13±0.10)×105 L·mol-1,与钙结合的条件常数是(7.52±0.02)×102 L·mol-1。 相似文献
8.
A series of novel (oligo)thienyl-imidazo-benzocrown ethers were synthesised through a simple method and evaluated as fluorimetric chemosensors for transition metal cations. Interaction with Ni2+, Pd2+, and Hg2+ in ACN/DMSO solution (99:1) was studied by absorption and emission spectroscopy. Chemoselectivity studies in the presence of Na+ were also carried out and a fluorescence enhancement upon chelation (CHEF) effect was observed following Hg2+ complexation. Considering that most systems using fluorescence spectroscopy for detecting Hg2+ are based on the complexation enhancement of the fluorescence quenching (CHEQ) effect, the present work represents one of the few examples for sensing of Hg2+ based on a CHEF effect. 相似文献
9.
In this paper, we demonstrate an electrochemiluminescence (ECL) enhancement of tris(2,2-bipyridyl)ruthenium(II) (Ru(bpy)32+) by the addition of silver(I) ions. The maximum enhancement factor of about 5 was obtained on a glassy carbon electrode in the absence of co-reactant. The enhancement of ECL intensity was possibly attributed to the unique catalytic activity of Ag+ for reactions between Ru(bpy)33+ with OH. The higher enhancement was observed in phosphate buffer solutions compared with that from borate buffer solutions. This resulted from the fact that formation of nanoparticles with large surface area in the phosphate buffer solution exhibited high catalytic activity. The amount of Ag+, solution pH and working electrode materials played important roles for the ECL enhancement. We also studied the effects of Ag+ on Ru(bpy)32+/tripropylamine and Ru(bpy)32+/C2O42− ECL systems. 相似文献
10.
Mahendra Sonawane Kundan Tayade Suban K. Sahoo Chatur P. Sawant 《Journal of Coordination Chemistry》2016,69(18):2785-2792
A new lawsone-based azo-dye 2-hydroxy-3-((pyridin-2-ylmethyl)diazenyl)naphthalene-1,4-dione (1) was synthesized and applied for sensing of metal ions. Receptor 1 showed selective fluorescent and colorimetric response for the detection of Cu2+ and Fe3+ over other tested metal ions. The fluorescence intensity of 1 was significantly quenched allowing detection of Fe3+ and Cu2+ down to 0.61 and 6.06 μM, respectively. The binding has been established by fluorescence spectroscopic method. Receptor 1 provided a 1?:?1 binding scaffold for recognition of Fe3+ and Cu2+ ions with the association constant of 3.33 × 106 and 3.33 × 105 M?1, respectively. The B3LYP/6-31G/LANL2DZ method was employed for the optimization of 1 and 1·Fe3+ and 1·Cu2+. 相似文献
11.
The fluorescence intensity of the enoxacin (ENX)-Tb3+ complex enhanced by DNA was studied. On the basis of this study, an environmentally friendly fluorescence probe of enoxacin-Tb3+ for the determination of single-stranded and double-stranded DNA was developed. Under the optimal conditions, the enhanced fluorescence intensity was in proportion to the concentration of DNA in the range of 2.0 × 10−8 to 2.0 × 10−6 g mL−1 for hsDNA, 1.0 × 10−8 to 1.0 × 10−6 g mL−1 for ctDNA and 5.0 × 10−9 to 1.0 × 10−6 g mL−1 for thermally denatured ctDNA. The detection limits (S/N = 3) were 5.0, 9.0 and 3.0 ng mL−1, respectively. The interaction modes between ENX-Tb3+ and DNA and the mechanism of the fluorescence enhancement were also discussed in details. The experimental results from UV absorption spectra, fluorescence spectra and the competing combination tests between the ENX-Tb3+ complex and EB probe indicated that the possible interaction modes between enoxacin-Tb3+ complex and DNA had at least two different binding modes: the electrostatic binding and the intercalation binding. Additionally, this fluorescence probe was used to study the interaction between heavy metals and DNA. 相似文献
12.
A novel fluorescent chemical sensor for the highly sensitive and selective determination of Fe3+ ions in aqueous solutions is prepared. The iron sensing system was prepared by incorporating 5-(8-hydroxy-2-quinolinylmethyl)-2,8-dithia-5-aza-2,6-pyridinophane (L) as a neutral Fe3+-selective fluoroionophore in the plasticized PVC membrane containing sodium tetraphenylborate as a liphophilic anionic additive. The response of the sensor is based on the strong fluorescence quenching of L by Fe3+ ions. At pH 5.5, the proposed sensor displays a calibration curve over a wide concentration range from 6.0 × 10−4 to 1.0 × 10−7 M, with a relatively fast response time of less than 2 min. In addition to a high stability and reproducibility, the sensor shows a unique selectivity toward Fe3+ ion with respect to common coexisting cations. The proposed fluorescence optode was applied to the determination of iron(III) content of straw of rice, spinach and different water samples. The fluorescent sensor was also used as a novel probe for Fe3+/Fe2+ speciation in aqueous solution. 相似文献
13.
We introduce a new rhodamine-based fluorescent chemosensor, FD8 which exhibits a distinct two-photon excited fluorescence (TPEF) on/off characteristic upon binding Cr3+ ions. By coordination with metal cation, conformation of FD8 changes from spirocyclic to open-ring, resulting in remarkable enhancement of absorption and fluorescence both in one- and two-photon excitations. As a result, a 29-fold enhancement of two-photon excited fluorescent intensity was observed when 10 eq. Cr3+ was added to the FD8 solution. The detection limit of Cr3+ cation concentration down to 1 μM (0.01 eq. of FD8) was achieved under our experimental condition. Besides the excitation within ultraviolet regime by fluorescence resonance energy transfer (FRET) mechanism, the TPEF on/off behavior further extends the excitation to near infrared regime (the biological optimal window of 700-1200 nm), and shows more effective sensitivity. The broad excitation wavelength, on/off fluorescence and high selectivity to Cr3+ enable FD8 to be a powerful Cr3+ cation sensor with potential application, especially in biological detection. To the best of our knowledge, this is the first report about two-photon fluorescent sensor for Cr3+ ions. 相似文献
14.
K. Zhuravlev V. Tsaryuk V. Kudryashova V. Zolin Yu. Yakovlev J. Legendziewicz 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2009,72(5):1020-1025
It was found, that alkali metal-europium dinitrosalicylates of composition M3Eu(3,5-NO2-Sal)3·nH2O (M = Li, Na, K, Cs) are intense red luminophores with wide excitation band. Using methods of optical spectroscopy we studied the influence of nitrogroups and alkali metal counterions on Eu3+ luminescence efficiency and on processes of excitation energy transfer to Eu3+ ion in compounds synthesized. The Eu3+ luminescence and Eu3+ luminescence excitation spectra, as well as vibrational IR and Raman spectra were investigated. Details of the structure of compounds were discussed. The network of hydrogen bonds in lanthanide dinitrosalicylates is weakening at introduction of large alkali metal ions in compounds and at the increase of the temperature. As a consequence, the long-wavelength shift of the intraligand charge transfer (ILCT) band in Eu3+ excitation spectra arises at inclusion of Cs+ cations instead of Li+ in the crystal lattice of europium dinitrosalicylates and at heating of these compounds. To obtain the energy of the lowest excited triplet state the phosphorescence spectra of alkali metal-gadolinium compounds M3Gd(3,5-NO2-Sal)3·nH2O, of alkali metal dinitrosalicylate and salicylate salts were measured with time delay. Change of the energies of ligand electronic states and ligand–metal charge transfer state (LM CTS) can give a two-three orders of magnitude enhancement of the Eu3+ luminescence efficiency in dinitrosalicylates in comparison with salicylates and ten-fold enhancement at the substitution of Li+ and Na+ for Cs+ in dinitrosalicylates. 相似文献
15.
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
16.
Pyoverdine A(PvdA)是荧光假单胞菌分泌的一种水溶性较高的黄绿色荧光铁载体。在50mmol·L-1Tris-HCl,pH8.0条件下,使用紫外-可见吸收差光谱、荧光光谱研究了铽(Ⅲ)与荧光铁载体PvdA的结合。结果表明铽(Ⅲ)可与PvdA结合形成1:1的配合物,条件结合常数为(4.44±0.82)×1014mol-1·L。在生理条件下,PvdA可竞争伴清蛋白N-,C-端结合的铽(Ⅲ)形成Tb-PvdA配合物;Tb-PvdA与荧光假单胞菌细胞表面受体FpvA结合形成Tb-PvdA-FpvA复合物。 相似文献
17.
It is found that the fluorescence intensity of morin-Al3+ complex can be greatly enhanced by proteins in the presence of cetyltrimethylammonium bromide (CTAB). It is considered that protein and CTAB provide a hydrophobic environment with low polarity and large viscosity, resulting in the fluorescence enhancement of morin-Al3+ complex. The experiments indicate that under optimum conditions, the enhanced intensity of fluorescence is in proportion to the concentration of proteins (such as bovine serum albumin (BSA), human serum albumin (HSA) and egg albumin (EA)) in the wide range, and their detection limits (S/N = 3) are 2.6 × 10−9, 1.4 × 10−8 and 1.6 × 10−8 g ml−1, respectively. This method has satisfactorily been used for the determination of protein in actual sample. In comparison with most of fluorimetric methods reported, this method is quick and simple, and has high sensitivity, wide linear range and good stability. 相似文献
18.
Mao-Qian Ran Jian-Ying Yuan Yuan-Hui Zhao Lan Mou Carl Redshaw 《Supramolecular chemistry》2016,28(5-6):418-426
AbstractThe fluorescent sensor (3) based on the 1,3-alternate conformation of the thiacalix[4]arene bearing the coumarin fluorophore, appended via an imino group, has been synthesised. Sensing properties were evaluated in terms of a colorimetric and fluorescence sensor for Zn2+ and F?. High selectivity and excellent sensitivity were exhibited, and ‘off-on’ optical behaviour in different media was observed. All changes were visible to the naked eye, whilst the presence of the Zn2+ and F? induces fluorescence enhancement and the formation of a 1:1 complex with 3. In addition, 3 exhibits low cytotoxicity and good cell permeability and can readily be employed for assessing the change of intracellular levels of Zn2+ and F?. 相似文献
19.
Three novel compounds bearing 2,7-dihydroxylnaphthalene capable of detecting Cu2+ or Fe3+ have been synthesised based on photoinduced electron transfer. The ability of these compounds for complex transition metal ions has been studied, and complex stoichiometry for Cu2+ and Fe3+ complex has been determined in the Tris–HCl (0.01 M DMSO/H2O (v/v) 1:1, buffer, pH 7.4) solution system by fluorescence titration experiments. These chemosensors form a 1:1 complex with Cu2+ or Fe3+ and show a fluorescent quenching with a binding constant of (4.46 ± 0.29) × 103 and (8.04 ± 0.26) × 104, respectively. 相似文献
20.
Red emitting phosphors of CaTiO3:Pr3+ nanoparticles with size ranging from 6 to 95 nm have been prepared by a coprecipitation technique and structurally characterized by X-ray diffraction, energy dispersive spectroscopy and scanning electron microscopy. The fluorescence and phosphorescence of CaTiO3:Pr3+ nanoparticles as a function of annealing temperature are investigated. It is found that fluorescence intensities monotonously increase with increasing temperature. However, a maximum in phosphorescence with the increase of annealing temperature occurs for the sample prepared at 700 °C. Based on the measurement of fluorescence emission, fluorescence excitation and reflectance spectra as well as time decay patterns of fluorescence and phosphorescence, it is demonstrated that the dependence of fluorescence and phosphorescence on annealing temperature originates from the decrease of surface defects with the increase of temperature. 相似文献