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1.
A Novel Hg<Superscript>2+</Superscript> Selective Ratiometric Fluorescent Chemodosimeter Based on an Intramolecular FRET Mechanism 总被引:1,自引:0,他引:1
A irreversible Hg2+ selective ratiometric fluorescence probe FR, a fluorescein fluorophore linked to a rhodamine B hydrazide by a thiourea spacer, was designed and synthesized. The developed
probe FR exhibited great ratiometric fluorescence enhancement and remarkable yellow-magenta color change toward Hg2+ with excellent selectivity in aqueous acetone solution, and the ratiometric fluorescence response to Hg2+ was not interfered by other metal cations including Fe3+, Co2+, Ni2+, Cr3+, Zn2+, Pb2+, Cd2+, Ca2+, Mg2+, Ba2+ and Mn2+. The linear range and the detection limit of this supposed ratiometric fluorescence method for Hg2+ were 0.0–10.0 × 10−6 and 5 × 10−8 M, respectively. 相似文献
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A new 7-nitrobenz-2-oxa-1,3-diazole (NBD) derived fluorescent probe (1) exhibiting high selectivity for Cu2+ detection, produced significant fluorescence quenching in the presence of Cu2+ ion, while the metal ions Ca2+, Cd2+, Co2+, Fe2+, Hg2+, Mg2+, Mn2+, Ni2+ and Zn2+ produced only minor changes in fluorescence. The apparent association constant (K
a) for Cu2+ binding in chemosensor 1 was found to be 1.22 × 103 M−1. The maximum fluorescence quenching activity caused by Cu2+ binding to 1 was observed over the pH range 6–10. 相似文献
4.
Studies on Interaction of Norfloxacin,Cu<Superscript>2+</Superscript>, and DNA by Spectral Methods 总被引:1,自引:0,他引:1
The interactions of norfloxacin (NFA), DNA, and Cu2+ are studied by fluorescence and UV-spectra method. According to the experimental results, it can be concluded that NFA can
form a steady binary complex with Cu2+. There is a linear relationship between the Fluorescence intensity of the norfloxacin–Cu2+–DNA system and the concentration of DNA. And when the concentration of the NFA is 1.95×10−5 mol L−1, they possess a good linearity in the concentration of DNA ranged from 4.7×10−6 to 2.8×10−5 mol L−1.It is a good method due to the high sensitivity and selectivity. 相似文献
5.
Zhuan Su Kangyu Chen Yuan Guo Haiping Qi Xiao-Feng Yang Minglei Zhao 《Journal of fluorescence》2010,20(4):851-856
A coumarin-based fluorescent chemosensor 1 for Zn2+ was designed and synthesized. Compound 1 exhibits lower background fluorescence due to intramolecular photoinduced electron transfer. However, upon mixing with Zn2+ in 30% (v/v) aqueous ethanol, a “turn-on” fluorescence emission is observed. The fluorescence emission increases linearly with Zn2+ 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 Zn2+ in water samples with satisfactory results. 相似文献
6.
Study on the New Fluorescence Enhancement System of Tb –N-(2 - Pyridinyl) Ketoacetamide-Et<Subscript>3</Subscript>N-Zn and its Application 总被引:1,自引:0,他引:1
A sensitive fluorescence enhancement system was developed for the determination of zinc (II). The fluorescence intensity of
the Tb- N- (2 - Pyridinyl) ketoacetamide (PKA) system was greatly enhanced by the addition of triethylamine (Et3N) and zinc nitrate in the methanol solution. The excitation and emission wavelengths were 329 nm and 546 nm, respectively.
Under optimal conditions, the fluorescence intensities varied linearly with the concentration of Zn2+ in the range of 8.0×10−7−5.0×10−6 M with a detection limit of 9.9×10−8 M. The interferences of some substances were described. This method was applied to the determination of amounts of Zn2+ in soybean, rice, and wheat, respectively. The results showed that the proposed procedure is a high selective, simple, and
rapid method to the determination of Zn2+ ion. The mechanism of fluorescence enhancement was also studied. 相似文献
7.
ABSTRACT A new multielement sensitive fluorescent probe, 1-(2-(phenylthio)ethyl)-2-(pyridin-2-yl)-1H-benzo[d]imidazole (L), has been synthesized by the reaction between 2-(pyridyl) benzimidazole and 2-chloroethyl phenyl sulfide. Excitation and emission wavelength of L are at 330 and 371 nm, respectively. Among various transition and nontransition metal ions, it can selectively read Zn2+ ion as the emission wavelength of L undergoes a red shift by 31 nm upon binding with Zn2+ in methanol. In the presence of Cd2+, Hg2+, and other common cations, the emission wavelength of L remains unchanged, and thus allows us to discriminate Zn2+ from its congeners. Both L and its Zn2+ complex are well characterized by different spectroscopic techniques like 1H-NMR, ESI-TOF (+) mass, FT-IR, and elemental analysis data. The binding constant value of the complexation reaction between L and Zn2+ is found as 724.6 M?1 in methanol. Density functional theoretical (DFT) studies nicely demonstrate the red shift in the emission wavelength of L upon binding with Zn2+. 相似文献
8.
Two highly photostable yellow–green emitting 1,8-naphthalimides 5 and 6, containing both N-linked hindered amine moiety and a secondary or tertiary cation receptor, were synthesized for the first time. Novel compounds
were configured as “fluorophore–spacer–receptor” systems based on photoinduced electron transfer. Photophysical characteristics
of the dyes were investigated in DMF and water/DMF (4:1, v/v) solution. The ability of the new compounds to detect cations was evaluated by the changes in their fluorescence intensity
in the presence of metal ions (Cu2+, Pb2+, Zn2+, Ni2+, Co2+) and protons. The presence of metal ions and protons was found to disallow a photoinduced electron transfer leading to an
enhancement in the dye fluorescence intensity. Compound 5, containing secondary amine receptor, displayed a good sensor activity towards metal ions and protons. However the sensor
activity of dye 6, containing a tertiary amine receptor and a shorter hydrocarbon spacer, was substantially higher. The results obtained indicate
the potential of the novel compounds as highly photostable and efficient “off–on” pH switchers and fluorescent detectors for
metal ions with pronounced selectivity towards Cu2+ ions. 相似文献
9.
Natalia A. Bumagina Elena V. Antina Anna Yu. Nikonova Mikhail B. Berezin Alexander A. Ksenofontov Anatoly I. Vyugin 《Journal of fluorescence》2016,26(6):1967-1974
3,3′,5,5′-Tetraphenyl-2,2′-dipyrromethene was described as a highly sensitive and selective Off-on fluorescent colorimetric chemosensor for Zn2+ based on the chelation-enhanced fluorescence (CHEF) effect. The reaction of dipyrromethene ligand with Zn2+ induces the formation of the [ZnL2] complex, which exhibits the increasing fluorescence in 120 fold compared with ligand in the propanol-1/cyclohexane (1:30) binary mixture. The Zn2+ detection limit was 1.4 × 10?7 М. The UV-Vis and fluorescence spectroscopic studies demonstrated that the dipyrromethene sensor was highly selective toward Zn2+ cations over other metal ions (Na+, Mg2+, Co2+, Ni2+, Fe3+, Cu2+, Mn2+, Cd2+ and Pb2+), excluding Hg2+. 相似文献
10.
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+, Mg2+, Ba2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Ag+, Zn2+, Cd2+ and Hg2+ 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 Co2+ 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