[Show abstract][Hide abstract] ABSTRACT: A naphthalene derivative 2-hydroxy-α-naphthaldehyde-(2′-methylquinoline-4′-formyl) hydrazone (HL) as a fluorescent chemosensor for Al3+/Zn2+ in ethanol and water (9:1, v/v) has been designed and synthesized. The receptor shows a large fluorescence enhancement at 509 nm and 543 nm in the present of Al3+ and Zn2+, respectively. The excited-state intramolecular proton transfer (ESIPT) process, coupled with photoinduced electron transfer (PET) process are proposed to explain the observed spectral response.
[Show abstract][Hide abstract] ABSTRACT: A novel and simple chromone Schiff-base receptor 7-methoxychromone-3-carbaldehyde-(indole-2-formyl) hydrazone (MCIH) was prepared. Among the various metal ions, only Al3+ induces the fluorescence enhancement and results in “OFF–ON” type sensing with excellent selectivity and high sensitivity in ethanol system. Upon binding of Al3+, a significant fluorescence enhancement with an “OFF–ON” ratio over 500-fold was triggered and it features visible light excitation (423 nm) and emission (507 nm) profiles. However, other metal ions had no such significant effect on the fluorescence. Also, MCIH can severe as a highly selective chemodosimeter for Al3+ with “naked-eye” detection, which is easily observed from colorless to yellow–green. The detection limit of MCIH for Al3+ detection was as low as 5×10−8 M level.
Journal of Luminescence 11/2014; 155:84–88. DOI:10.1016/j.jlumin.2014.06.023 · 2.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A new fluorescent probe, which contains rhodamine and chromone moieties, was designed and synthesized for selective recognition Al3+ and Zn2+. The sensor showed immediate responses toward Al3+ and Zn2+ in different systems. The sensor exhibited highly selective and sensitive "off-on" fluorescent responses toward Al3+ based on the ring-opening mechanism of the rhodamine spirolactam in an acetonitrile: water solution (excitation 500 nm and emission 550 nm). Whereas, in an ethanol:water solution, the sensor showed a significant fluorescent enhancement for Zn2+ over a wide range of tested metal ions (excitation 424 nm and emission 496 nm), due to chelation-enhanced fluorescence process generated along with the photoinduced electron transfer process suppressed simultaneously. Moreover, the prepared zinc complex of the sensor could detect Al3+ on the basis of fluorescence resonance energy transfer mechanism and the detection limit for Al3+ was as low as 1.83 x 10(-7) M.
Sensors and Actuators B Chemical 11/2014; 203:550-556. DOI:10.1016/j.snb.2014.07.017 · 4.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: An efficient fluorescent Al3+ receptor, 4-N,N-diethylaminosalicylicaldehyde -(2'-methylquinoline-4-formyl) hydrazone (HL) has been synthesized and characterized by physico-chemical and spectroscopic tools. Upon addition of Al3+ to an aqueous solution of HL, it shows 125-fold enhancement of fluorescence intensity at 550 nm. Photoinduced electron transfer (PET) process, coupled with the intramolecular charge transfer (ICT) process, are proposed to explain the observed spectral response. The lowest detection limit for Al3+ is determined as 6 x 10(-7) M in ethanol and water (4:1, v/v).
[Show abstract][Hide abstract] ABSTRACT: A fluorescence probe, 8-formyl-7-hydroxyl-4-methyl coumarin - (2'-methylquinoline-4-formyl) hydrazone (L) has been synthesized. The chemosensor is found preferential binding to Al(3+) in presence of other competitive ions with associated changes in its optical and fluorescence spectra behavior. Upon addition of Al(3+) to a solution of L, it shows 200-fold enhancement of fluorescence intensity which might be attributed to form a 2:1 stoichiometry of the binding mode of LAl(III) and the chelation enhanced fluorescence (CHEF) process at 479nm in ethanol. The lowest detection limit for Al(3+) is determined as 8.2×10(-7)M.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 05/2014; 133C:38-43. DOI:10.1016/j.saa.2014.05.033 · 2.35 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A fluorescent Al3+ chemo-sensor, 1-phenyl-3-methyl-5-hydroxypyrazole-4-acetone-(3′,4′-dimethylpyrrole-2′-formyl) hydrazone (L), has been synthesized and characterized. L can detect Al3+ in ethanol solution with a significant fluorescence enhancement of a turn-on ratio over 155-fold due to the formation of a 1 : 1 complex which is based on the molar ratio between L and Al3+ ions, and the 1 : 1 stoichiometric complexation can be obtained from density functional theory calculations. No significant interference of other metal ions such as Na+, K+, Mg2+, Ca2+, Ni2+, Zn2+, Cd2+, Co2+, Cu2+, Fe3+, Cr3+, Pb2+, and Ag+ was found. The detection limit for Al3+ was 5 × 10−9 M in ethanol.
[Show abstract][Hide abstract] ABSTRACT: A new Schiff-base ligand (1) with good fluorescence response to Al(3+), derived from 2-oxo-quinoline-3-carbaldehyde and nicotinic hydrazide, had been synthesized and investigated in this paper. Spectroscopic investigation revealed that the compound 1 exhibited a high selectivity and sensitivity toward Al(III) ions over other commonly coexisting metal ions in ethanol, and the detection limit of Al(3+) ions is at the parts per billion level. The mass spectra and Job's plot confirmed the 1:1 stoichiometry between 1 and Al(3+). Potential utilization of 1 as intracellular sensors of Al(3+) ions in human cancer (HeLa) cells was also examined by confocal fluorescence microscopy.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 01/2014; 124C:59-63. DOI:10.1016/j.saa.2013.12.076 · 2.35 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A new Zn(ii) complex was synthesized based on a new Salen-type tetradentate N2O2 bisoxime chelate ligand (H2L) derived from 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) and 1,2-bis(aminooxy)ethane. Single-crystal X-ray diffraction analysis reveals that the structure of the Zn(ii) complex features a three-dimensional (3D) cyclic supramolecular system via intermolecular hydrogen bonds. Moreover, the solid-state photoluminescent properties demonstrate that the Zn(ii) complex exhibits unusual luminescence mechanochromism tuned by CH3OH.
[Show abstract][Hide abstract] ABSTRACT: A simple Schiff-base receptor 7-methoxychromone-3-carbaldehyde-(pyridylformyl) hydrazone (MCNH) was prepared. It exhibits an "off-on-type" mode with high sensitivity in the presence of Al(3+). This compound could be used as Al(3+) probe in ethanol and it features visible light excitation (433nm) and emission (503nm) profiles. Upon binding of Al(3+), a significant fluorescence enhancement with a turn-on ratio over 800-fold was triggered. However, other metal ions had no such significant effect on the fluorescence. MCNH can also be used as a colorimetric chemosensor for Al(3+), which is easily observed from colorless to yellow-green by the naked-eye. The detection limit of MCNH for Al(3+) was as low as 1.9×10(-7)M.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 10/2013; 118C:760-764. DOI:10.1016/j.saa.2013.09.062 · 2.35 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A novel fluorescent sensor, 7-hydroxy-4-methylcoumarin-8-carbaldehyde-(fluorescein) hydrazone was designed and synthesized for selective recognition of Zn2+ in HEPES buffer medium of PH 7.4. This reagent could be used as a probe for Zn2+ by monitoring changes in the absorption and the fluorescence spectral patterns. More importantly, this sensor displays an extreme selectivity, sensitivity and color change for Zn2+ over other earth- and transition metal ions, which was mainly due to the spirolactam ring-opening power of Zn2+. Upon the addition of Zn2+, an overall emission change of 33-fold was observed and the detection limit was low as 6.54 ppb. Photoinduced electron transfer process, coupled with the intramolecular charge transfer process, are proposed to explain the observed spectral response.
Dyes and Pigments 10/2013; 99(1):1–5. DOI:10.1016/j.dyepig.2013.04.018 · 3.97 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In the paper, a novel rhodamine6G based fluorescent chemosensor bearing 3-carbaldehyde chromone was designed and synthesized. According to the fluorescence behavior toward several metal ions, it showed highly selectivity and sensitivity to Zn(II) over other commonly coexistent metal ions (Cu(II), Cd(II), Hg(II), Mg(II), K(I), Pb(II), Fe(III) and Cr(III)) in aqueous environment (pH = 7.4). Meanwhile the binding constant between Zn(II) and chemosensor achieved 6.21 × 10(11) M(-1) in aqueous media. Moreover, according to the Job plot, 1:1 stoichiometry between Zn(II) and sensor was deduced in aqueous media (pH = 7.4). The good selectivity and sensitivity in aqueous media effectively enhanced the application value of the fluorescent chemosensor for Zn(II).
Journal of Fluorescence 07/2013; 23(6). DOI:10.1007/s10895-013-1255-1 · 1.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A novel sensor, 7-Hydroxy-4-methylcoumarin-8-carbaldehyde-(rhodamine) hydrazone (l) has been synthesized and investigated as a fluorescence chemosensor for Ca2+ in acetonitrile. The compound is found preferential binding to Ca2+ in presence of large excess of other competitive ions with associated changes in its optical and fluorescence spectral behavior. Upon the addition of Ca2+, an overall emission change of 64-fold was observed. Photoinduced electron transfer (PET) process, coupled with the intramolecular charge transfer (ICT) process, are proposed to explain the observed spectral response.
Journal of Luminescence 07/2013; 139:79–83. DOI:10.1016/j.jlumin.2013.02.019 · 2.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A fluorescent probe for Al3+, 4-(1′-phenyl-3′-methyl-5′-hydroxypyrazole)-1-acetone-(2′-hydroxybenzoyl) hydrazone (L), was prepared through a simple synthetic route. The fluorescent probe can detect Al3+ ions sensitively, in ethanol solution with the detection limit of 2.5 × 10−8 M via photoinduced electron transfer progress. The presence of interfering metal ions and chelators had little influence on the selectivity of Al3+. The probe could serve as an excellent chemodosimeter for Al3+ in ethanol.
[Show abstract][Hide abstract] ABSTRACT: A Schiff base derived from two similar pyrazolone derivatives 4-(1′-phenyl-3′-methyl-5′-hydroxypyrazol-4′-yl)methyleneiminophenazone and its Tb(III) and Dy(III) complexes were synthesized and characterized. The molecular structures of the ligand and Dy(III) complex were determined by X-ray crystal diffraction. The DNA-binding properties of the compounds were investigated by electronic absorption spectroscopy, fluorescence spectra, and viscosity measurements. The compounds interact with DNA through intercalation. The compounds also exhibit potential antioxidant activities in vitro and the antioxidant activity of the Ln(III)-complexes was stronger than that of the ligand alone and some standard antioxidants, such as mannitol and vitamin C.
[Show abstract][Hide abstract] ABSTRACT: In the article, a novel fluorescent probe for the copper cation based on fluorescence quenching mechanism was designed. It exhibited high selectivity for Cu(II) over other common metal ions in aqueous media. Furthermore the coordination between Cu(II) and the organic molecule sensor fabricated an interesting 1D chain coordination polymer framework.
[Show abstract][Hide abstract] ABSTRACT: A Schiff base derived from 2-oxo-quinoline-3-carbaldehyde-4-aminophenazone and its Cu(II), Zn(II) and Ni(II) complexes were
synthesized. The molecular structures of the Zn(II) and Ni(II) complexes were determined by X-ray crystal diffraction. The
DNA-binding modes of the compounds were investigated by spectroscopic methods, viscosity measurements and ethidium bromide-DNA
displacement experiments. The experimental evidence indicated the compounds interact with calf thymus DNA through intercalation.
Additionally, the compounds exhibited potential antioxidant properties in in vitro studies, and the Cu(II) complex was the
most effective. The solid-state fluorescence properties of the Zn(II) complex were studied.
Transition Metal Chemistry 08/2011; 36(5):489-498. DOI:10.1007/s11243-011-9494-y · 1.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In the paper, a novel fluorescent sensor (1) based on 8-hydroxyquinoline carbaldehyde Schiff-base was synthesized and characterized. This fluorescent sensor exhibited high selectivity for Al3+ over other metal ions with the detection limit reaching below 10− 7 M under weak acid aqueous conditions. These suggested that 1 could be served as a highly selective and sensitive fluorescence sensor for aluminum ion in acid medium.
[Show abstract][Hide abstract] ABSTRACT: A new fluorescent Zn2+ chemosensor, 8-(7′-Hydroxy-4′-methylcoumarin-8′-yl-) methyleneiminoquinoline (L) was designed and synthesized. This complex could act as highly sensitive and selective fluorescent probe for Zn2+ in THF (tetrahydrofuran). However, other metal ions gave little fluorescence change.