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1.
A novel fluorescence chemosensor for Hg 2+ ion has been developed by the assembly of fluorescence Bis-Schiff base PMBA within the channels of CPTES-modified SBA-15. The ordered porous structure of SBA-15 is still retained on the hybrid chemosensor material PMBA-SBA. A remarkable fluorescence quenching of PMBA-SBA by Hg 2+ ion was attributed to heavy atom effect of Hg 2+ ion. The linear detecting range of the hybrid mesoporous chemosensor for Hg 2+ ion is 2-15 μM and the lowest detection limit is 0.6 μM in ethanol/water (9:1, v/v) solution. 相似文献
2.
A new pyrene derivative (chemosensor 1) containing a picolinohydrazide moiety exhibits high selectivity for Cu 2+ ion detection in mixed aqueous media (CH 3OH:H 2O = 7:3). Significant fluorescence enhancement was observed with chemosensor 1 in the presence of Cu 2+. However, the metal ions Ag +, Ca 2+, Cd 2+, Co 2+, Cu 2+, Fe 2+, Fe 3+, Hg 2+, K +, Mg 2+, Mn 2+, Ni 2+, Pb 2+, and Zn 2+ produced only minor changes in fluorescence for the system. The apparent association constant ( K
a) of Cu 2+ binding in chemosensor 1 was found to be 2.75*10 3 M −1. The maximum fluorescence enhancement caused by Cu 2+ binding in chemosensor 1 was observed over the pH range 5–8. Moreover, by means of fluorescence microscopy experiments, it is demonstrated that 1 can be used as a fluorescent probe for detecting Cu 2+ in living cells. 相似文献
3.
A new anisidine possessing benzothiaozle-based chemosensor ( 1) has been designed and synthesized. The chemosensor 1 was designed to provide hard base environment for ratiometric detection of comparatively less studied Al 3+ ions. In CH 3CN, the fluorescence spectra of chemosensor 1 red shifted from 368 to 430 nm with addition of Al 3+ and Hg 2+ ions; while Cu 2+ ions caused quenching of emission intensity of 1. These differential changes observed with Al 3+ and Cu 2+ ions addition enabled chemosensor 1 to construct “NOR” and “TRANSFER” logic gates. 相似文献
4.
A new NBD-rhodamine dye ( 1) was developed as a colorimetric and ratiometric fluorescent chemosensor for Hg 2+ with good selectivity in aqueous ethanol solutions under neutral to basic conditions. Sensor 1 showed absorption at 468 nm and a weak emission at 529 nm ( ? F ?=?0.063) in ethanol/aqueous tris buffer (9:1, v/v) of pH 9.17 solution. Bathochromic shifts in both absorption (492 nm) and fluorescence spectra (569 nm, ? F ?=?0.129), respectively upon addition of 2 equiv. of Hg 2+ were observed. The ring-opening reaction of the spirolactam form to the corresponding xanthene form was not found. The interaction of Hg 2+ with chemosensor 1 resulted in the deprotonation of the secondary amine conjugated to the NBD component so that the electron-donating ability of the N atom was enhanced. Deprotonation-ICT mechanism of secondary amines was suggested for the ratiometric fluorescent chemosensing for Hg 2+. 相似文献
5.
A coumarin-based fluorescent chemosensor 1 for Zn 2+ was designed and synthesized. Compound 1 exhibits lower background fluorescence due to intramolecular photoinduced electron transfer. However, upon mixing with Zn 2+ in 30% ( v/v) aqueous ethanol, a “turn-on” fluorescence emission is observed. The fluorescence emission increases linearly with Zn 2+ concentration in the range 0.5–10 μmol L −1 with a detection limit of 0.29 μmol L −1. No remarkable emission enhancement was, however, observed for other metal ions. The proposed chemosensor was applied to
the determination of Zn 2+ in water samples with satisfactory results. 相似文献
6.
A chemosensor, 2,2′-(1,4-phenylenedivinylene)bis-8-acetoxyquinoline ( 1), its fluorescent sensing behavior toward representative alkali ions (Na +, K +), alkaline earth ions (Mg 2+, Ca 2+), and transition-metal ions (Ni 2+, Cu 2+, Zn 2+, Hg 2+, Pb 2+, Cd 2+) was intensively investigated. The compound ( 1) exhibited pronounced Hg 2+ selective on–off-type fluoroionophoric properties among the representative ions in DMF/ethanol (1:9, v/v) solution. Moreover, the highly Hg 2+-selective fluorescence quenching property in conjunction with a visible colorimetric change from colorless to light yellow can be observed, leading to potential fabrication of both “naked-eye” and fluorescent detection of Hg 2+. 相似文献
7.
An efficient “off–on” type fluorescent chemosensor, (E)-N′-(4-(diethylamino)-2-hydroxybenzylidene)-2-hydroxybenzohydrazide ( H 2 L), based on Schiff base for the determination of Al 3+ has been designed, synthesized, and evaluated. Upon treated with Al 3+, the fluorescence of H 2 L was enhanced 45-fold due to the chelation-enhanced fluorescence (CHEF) effect based on the formation of a 1:1 complex between the chemosensor and Al 3+. Other metal ions, such as Na +, K +, Mg 2+, Ca 2+, Cu 2+, Ga 3+, Zn 2+, Cr 3+, Cd 2+, Ag +, Fe 3+, In 3+, Mn 2+, Pb 2+, Co 2+, and Ni 2+ had little effect on the fluorescence. The results demonstrate that the chemosensor H 2 L has stronger affinity with Al 3+ than other metal ions. The detection limit of H 2 L for sensing Al 3+ is 3.60 × 10 ?6 M in EtOH–H 2O (3:7, v/v) solution. And the recognizing behavior has been investigated both experimentally and computationally. 相似文献
8.
A new 7-nitrobenz-2-oxa-1,3-diazole (NBD) derived fluorescent probe ( 1) exhibiting high selectivity for Cu 2+ detection, produced significant fluorescence quenching in the presence of Cu 2+ ion, while the metal ions Ca 2+, Cd 2+, Co 2+, Fe 2+, Hg 2+, Mg 2+, Mn 2+, Ni 2+ and Zn 2+ produced only minor changes in fluorescence. The apparent association constant ( K
a) for Cu 2+ binding in chemosensor 1 was found to be 1.22 × 10 3 M −1. The maximum fluorescence quenching activity caused by Cu 2+ binding to 1 was observed over the pH range 6–10. 相似文献
9.
A new pyrene-based chemosensor ( 1) exhibits excellent selectivity for Fe 3+ ions over a wide range of tested metal ions Ag +, Ca 2+, Cd 2+, Co 2+, Cu 2+, Fe 2+, Hg 2+, K +, Mg 2+, Mn 2+, Ni 2+, Pb 2+, and Zn 2+. The binding of Fe 3+ to chemosensor 1 produces an emission band at 507 nm due to the formation of a Py-Py* excimer that is induced by Fe 3+-binding. The binding ratio of 1-Fe 3+ was determined to be 1:1 from a Job plot. The association constant of 1-Fe 3+ complexes was found to be 1.27?×?10 4 M ?1 from a Benesi-Hildebrand plot. In addition, fluorescence microscopy experiments show that 1 can be used as a fluorescent probe for detecting Fe 3+ in living cells. 相似文献
10.
The reactions of fullerene[C 60] with 2′-azidoethyl 2,3,4,6-tetra- O-acetyl- α- d-mannopyranoside ( 2a) and 2′-azidoethyl 2,3,4,6-tetra- O-acetyl- β- d-galactopyranoside ( 2b) under ultrasonic irradiation cause the cycloaddition of 2′-azidoethyl glycosides to fullerene[C 60] and lead to d-glycosyl fullerene[C 60] derivatives 3a and 3b, respectively. The glycosyl fullerene[C 60] derivatives were characterized by 1H and 13C NMR, UV–vis, FAB-MS, FT-IR spectra and were a 1:1 glycoside fullerene [C 60]-adduct. 相似文献
11.
Novel probes represented connection of pyrene as chromophore and sterically hindered amine stabilizers (HAS) in the form of esters of 2-(1-pyrenyl)acrylic acid were synthesized. HAS was in the form of parent amine (PAP) as well as stable nitroxyl radical form (PAP-NO .). Photophysics of these probes were compared with their precursor as 2-(1-pyrenyl)acrylic acid (PAA) and its methyl ester (PAM). The fluorescence spectrum of PAA strongly depends on the acidity of the solution. The spectrum in neutral methanol indicates that it originates from the anionic form –COO −. Changes of acidity or basicity of methanol solution resulted in the changes of shape, position as well as the intensity of fluorescence band. This is due to the presence of protolytic equilibria, either in the ground state or in the singlet excited state, leading to the formation of molecular form –COOH and the cationic form –COOH 2+. The ester analogues did not show any changes in various pH conditions. Fluorescence of all probes depends on the polarity of solvents and the presence of oxygen. Intermolecular quenching was studied with external quenchers TEMPO and oxygen and the data were compared with the intramolecular quenching using 1′-oxo-2′,2′,6′,6′-tetramethyl-4′-piperidinyl-2-(1-pyrenyl)acrylate (PAP-NO .). 相似文献
12.
A novel fluorescent chemosensor rhodamine B phenyl hydrazide (RBPH) for Hg 2+ was designed and synthesized. This probe is highly sensitive, selective, and irreversible for Hg 2+ and exhibits fluorescent response at 580 nm. RBPH also displayed detectable color change from colorless to pink upon treatment with Hg 2+. This property has been utilized as naked eye detection for Hg 2+ in various industrial samples. Fluorescence microscopic experiments demonstrated that this chemosensor is cell permeable and can be used for fluorescence imaging of Hg 2+ in cellular media. This probe can detect Hg 2+ with good linear relationships from 1 to 100 nM with r?=?0.99983 and the limit of detection were found to be 0.019 nM with?±?0.91 % RSD at 10 nM concentrations. 相似文献
13.
Three novel diphosphine-Pt-disulfide complexes were synthesized and characterized by 1H NMR, mass spectrometry and elemental analysis. As a diphosphine, 1,8-bis(diphenylphosphino)naphthalene (dppn), rac-2,2 ′-bis(diphenylphosphino)-1,1 ′-binaphthyl (dppbn), or 1,1 ′-bis(diphenylphosphino)ferrocene (dppf) was employed and chelated to the Pt(II) center. As an anion, p-tolylsulfide (4-SC 6H 4CH 3) was incorporated to Pt(II) center subsequently, yielding (dppn)Pt(4-SC 6H 4CH 3) 2 ( 1), (dppbn)Pt(4-SC 6H 4CH 3) 2 ( 2), or (dppf)Pt(4-SC 6H 4CH 3) 2 ( 3). The photophysical properties of the resulting Pt complexes were investigated with UV–VIS spectroscopy, photoluminescence (PL) spectroscopy and transient PL. Charge Transfer absorptions between the metal and the ligand of 2 and 3 were observed at 320–350 nm in the UV–VIS spectra whereas such noticeable absorption was not observed in 1. The solid films of 1 and 3 showed luminescence at 600 and 580 nm, respectively, while that of 2 did not show emission at the room temperature. The complex 3 exhibited two excited state lifetimes, 23 and 125 ns, at room temperature, and the weighting factor for 125 ns state is only 10% of that for 23 ns one. It means that the prominent luminescence was fluorescence and the intersystem crossing through LS coupling is relatively weak. 相似文献
14.
A novel conjugated molecule, L, based on 2,4,5-triphenylimidazole and 6-phenyl-2,2′-bipyridine (HC ∧N ∧N) was synthesized in two steps. The molecule can recognize Fe 3+ in aqueous solution (THF/H 2O, 1/1, v/v) by the appearance of new emission bands at 416 and 442 nm, which can be attributed to the emission of the newly formed L-Fe 3+ complex. The binding constant of the complex was calculated to be (6.6±0.39)×10 3 M −1, and its formation was also confirmed by the appearance of isosbestic points at 312 and 381 nm in the UV-visible spectral titration experiment. While other transition and rare-earth metal ions, such as Mn 2+, Fe 2+, Co 2+, Ni 2+, Zn 2+, Cd 2+, Hg 2+, Pb 2+, Eu 3+ and Nd 3+, can only cause some decrease of L's fluorescence, alkali and alkaline earth metal ions, such as Li +, Na +, K +, Mg 2+ and Ca 2+, almost have no effect on L's fluorescence. The fluorescence of L can be recovered by the addition of EDTA to the L-Fe 3+ system just due to EDTA's stronger chelating ability than that of L. 相似文献
15.
A simple and novel Schiff base chemosensor (BMHM) based on benzimidazole was synthesized. In ethanol–water (1:1, v/v) medium on varying concentrations of Zn2+ chemosensor exhibited a strong and quick turn on fluorescence response. The Zn2+ recognition was based on the Chelation–enhanced fluorescence effect. The binding constant and limit of detection for BMHM-Zn2+ complexation were estimated to be 7.99?×?104 M?1 and 0.148 µM, respectively. The extreme fluorescent enhancement caused by Zn2+ binding in chemosensor BMHM occurred at a pH range of 6–7. The practical use of chemosensor BMHM was tested by determination of Zn2+ in real water samples and comparing the results with the data obtained using high resolution inductively coupled plasma mass spectrometry. 相似文献
16.
A new fluorescent chemosensor 2-(2-thiophene)imidazo [4,5,f]-1,10-phenanthroline ( L) was prepared and characterized. By adding univalent or divalent metal ions such as Na +, K +, Mg 2+, Ba 2+, Mn 2+, Fe 2+, Co 2+, Ni 2+, Cu 2+, Ag +, Zn 2+, Cd 2+ and Hg 2+ ions into the solution of L in DMF under buffered conditions with the working pH ranging from 7.0 to 8.0, we found that L could be used to detect K + ratiometricly and it could also be applied to sense Co 2+ with the phenomenon of fluorescence quenching of L. While the response behavior of L was not discernibly affected by other examined metal ions. 相似文献
17.
The condensation product ( L) of 4-methoxybenzaldehyde and ethylenediamine has been synthesised and characterised. L showed a 21 times enhancement in fluorescence intensity on interaction with Ce 3+ in CH 3OH at λ max?=?360 nm when excited with 270 nm photons. Metal ions K +, Na +, Al 3+, Co 2+, Hg 2+, Cd 2+, Ni 2+, Zn 2+, Mn 2+, Mg 2+ and Ca 2+ do not interfere. The stoichiometry of binding and the binding constants were determined from spectroscopic data and found to be 1:1 and 10 4.8 M respectively. The detection limit was found to be 10 –5.2 M. The protonation/de-protonation of water molecules coordinated to Ce 3+ was found to show interesting behaviour on the fluorescence of L:Ce 3+. 相似文献
18.
Novel zirconia-based fluorescent terbium nanoparticles have been prepared as a fluorescent nanoprobe for time-resolved fluorescence bioassay. The nanoparticles were prepared in a water-in-oil (W/O) microemulsion consisting of a strongly fluorescent Tb 3+ complex, N, N, N1, N1-[2,6- bis(3′-aminomethyl-1′-pyrazolyl)-phenylpyridine]tetrakis(acetate)-Tb 3+(BPTA-Tb 3+), Triton X-100, hexanol, and cyclohexane by controlling co-condensation of Zr(OCH 2CH 3) 4 and ZrOCl 2. The characterizations by transmission electron microscopy and fluorometric methods indicate that the nanoparticles are uniform in size, 33± 4 nm in diameter, and have a fluorescence quantum yield of 8.9% and a long fluorescence lifetime of 2.0 ms. The zirconia-based fluorescent terbium nanoparticles show high stability against basic dissolution in a high pH aqueous buffer compared to the silica-based nanoparticles. A surface modification and bioconjugation method for the fluorescent nanoparticles was developed, and the nanoparticle-conjugated streptavidin (SA) was used for time-resolved floroimmunoassy (TR-FIA) of human prostate specific antigen (PSA). The result shows that the zirconia-based fluorescent terbium nanoparticles are useful as a fluorescent nanoprobe for time-resolved fluorescence bioassay. 相似文献
19.
Based on resonance energy transfer (FRET) from dansyl to rhodamine 101, a new fluorescent probe (compound 1) containing rhodamine 101 and a dansyl unit was synthesized for detecting Hg 2+ through ratiometric sensing in DMSO aqueous solutions. This probe shows a fast, reversible and selective response toward Hg 2+ in a wide pH range. Hg 2+ induced ring-opening reactions of the spirolactam rhodamine moiety of 1, leading to the formation of fluorescent derivatives that can serve as the FRET acceptors. Very large stokes shift (220 nm) was observed in this case. About 97-fold increase in fluorescence intensity ratio was observed upon its binding with Hg 2+. 相似文献
20.
A simple “off-on fluorescence type” chemosensor 1 3-((2-(dimethylamino)ethyl)amino)-N-(quinolin-8-yl)propanamide has been synthesized for Zn 2+. The receptor 1 comprises the quinoline moiety as fluorophore and the N,N ′-dimethylethane-1,2-diamine as a binding site. 1 showed a remarkable fluorescence enhancement in the presence of Zn 2+ in aqueous solution. Importantly, the chemosensor 1 could be used to detect and quantify Zn 2+ in water samples. In particular, this chemosensor could clearly distinguish Zn 2+ from Cd 2+. The binding properties of 1 with Zn 2+ ions were investigated by UV-vis, fluorescence, electrospray ionization mass spectroscopy and 1H NMR titration. 相似文献
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