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Journal of Fluorescence

Zohreh Shomali, Mohsen Kompany-Zareh, Nematollah Omidikia
The 8-17E DNAzyme is a temperature-dependent DNA metalloenzyme catalyzing RNA trans esterification in the presence of Pb2+ metal ions. Labeling the stems of the substrate and DNAzyme with the Cy3 and Cy5 respectively, the considered DNAzyme was studied by the fluorescence spectroscopy. The temperature-dependent variability of the Pb2+ -specific 8-17E DNAzyme catalytic sensor was investigated trough a number of successive temperature fluctuations from 4 to 25 °C to obtain information. Investigating underlined biochemical system reveals that in this sensor, free single strands Enzyme (Cy5-E) and Substrate (Cy3-S) have higher fluorescence intensities than hybridized forms, suggesting that the fluorophores are in a contact quenched...
February 18, 2019: Journal of Fluorescence
Sherin Philip, Sunny Kuriakose
Pyrene butyric acid (PBA) is a well studied lumophore for its exciting fluorescent properties. The current study focussed on a dendritic modification of PBA with hyperbranched polyglycerols (HPG) by Steglich esterification and further doping with iron oxide nanoparticles (IONP) of α-Fe2 O3 phase. The covalent coupling between HPG and PBA was confirmed by FTIR and 1 H-NMR spectra. The main objective of the study was to monitor the fluorescent properties of the modified and doped products. Steady state PL emission studies showed a considerable decrease in fluorescence intensity on HPG modification which almost completely disappeared on doping with IONP...
February 13, 2019: Journal of Fluorescence
Farzaneh Jaberi, Saeed Ostad Movahed, Ali Ahmadpour
After proper stimulation, long afterglow phosphors formulated as pigment in waterborne paints can emit light after the removal of the excitation light source. The encapsulation of SrAl2 O4 : Eu2+ , Dy3+ phosphor by TiO2 and SiO2 individually, and in combination by a precipitation method was studied. The water resistance and photoluminescence behavior of the coated phosphors as a pigment for potential use in waterborne photoluminescence paints were evaluated. It revealed that the TiO2- SiO2 content coating layer was precipitated on the studied phosphor successfully...
February 8, 2019: Journal of Fluorescence
Xiaorui Cao, Feifei Zhang, Yinjuan Bai, Xiaohu Ding, Wei Sun
A new "turn-on" fluorescent probe Py based on rhodamine and piperonaldehyde was designed and synthesized for detecting Fe3+ in cells. The free probe Py was non-fluorescent. While only upon addition of Fe3+ , the significant increase of the fluorescence and color were observed which could be visible directly by "naked-eye". The probe Py shows high selectivity and sensitivity for Fe3+ over other common metal ions in EtOH-H2 O (3/2, v/v) mixed solution. The association constant and the detection limit were calculated to be 4...
February 6, 2019: Journal of Fluorescence
Suh Mi Hwang, Dongju Yun, Cheal Kim
A new fluorometric chemodosimeter 2-amino-3-(((E)-3-(1-phenylimidazo[1,5-α]pyridin-3-yl)benzylidene)amino)maleonitrile (BPI-MAL) has been designed and synthesized for sensing hypochlorite. BPI-MAL showed a selective turn-on fluorescence for ClO- through hypochlorite-promoted de-diaminomaleonitrile reaction. It also could detect ClO- in the presence of various competitive anions including reactive oxygen species. Interestingly, sensor BPI-MAL was successfully applied as a fluorescent test kit for ClO- determination...
February 2, 2019: Journal of Fluorescence
Tengxuan Tang, Wenbo Guo, Yuping Zhang, Dongmei Xu
A new fluorescent sensor was designed and synthesized from 5-nitro-1,2-dihydroacenaphthylene, n-butyl amine and 1-(2-pyridyl)piperazine. In DMF/H2 O (3:1, v/v), the sensor showed excellent selectivity and sensitivity to Fe3+ with fast fluorescence enhancement and good anti-interference ability. The maximal fluorescence intensity was linearly proportional to the Fe3+ concentration (60-140 μM). The detection limit was 81 nM. The sensor could work in a pH span of 5.0-8.0. A 1:1 complex was formed reversibly between the sensor and Fe3+ ...
February 1, 2019: Journal of Fluorescence
Pornpat Sam-Ang, Komthep Silpcharu, Mongkol Sukwattanasinitt, Paitoon Rashatasakhon
A new symmetrical truxene derivative (TP3) containing three dipicolylamino peripheral groups is successfully synthesized in four synthetic steps with an overall yield of 42%. This hydrophilic fluorescent compound exhibits a maximum absorption wavelength at 375 nm, an emission maximum at 474 nm with an outstanding 58% quantum efficiency in THF-HEPES buffer mixture. The compound shows a highly selective fluorescence quenching towards Cu(II) ion with a detection limit of 0.06 ppm. The results from mass spectrometry and Job plot indicate that a 1:1 complex between TP3 and Cu(II) ion is responsible for the signal quenching...
January 28, 2019: Journal of Fluorescence
Takhe Yaba, Ranjoy Wangkhem, N Shanta Singh
A multicolor tunable CaWO4 :xDy3+ nanophosphors have been synthesized via hydrothermal route. X-Ray Diffraction and Fourier transform infrared confirm the formation of CaWO4 :Dy3+ nanophosphors. Transmission electron microscopy image and selected area electron diffraction (SAED) reveal the formation of nanosize and crystalline CaWO4 :Dy3+ . Dependence of energy transfer rate from WO4 2- to the activator (Dy3+ ) is observed from the photoluminescence studies. An enhancement of energy transfer efficiency from 36% to 90% is observed after annealing the as-prepared samples at 800 °C...
January 26, 2019: Journal of Fluorescence
Ya Xie, Liqiang Yan, Yujian Tang, Minghui Tang, Shaoyang Wang, Li Bi, Wanying Sun, Jianping Li
Smart and versatile salicylaldehyde Schiff's bases have been proved their excellent performances including large shocks shift, dual emission wavelengths and sensitive to environment for fluorescence analysis. Herein, a simple salicylaldehyde Schiff's base molecular (PBAS) with aggregation-induced emission (AIE) and the excited-state intramolecular proton-transfer (ESIPT) effects was constructed for detecting N2 H4 and ClO- . The highly specific and sensitive response to N2 H4 was witnessed by the fast turn-on of the strong blue fluorescence and to ClO- was observed by the rapid turn off of the weak green fluorescence simultaneous decomposing of the probe...
January 24, 2019: Journal of Fluorescence
Xian-Fu Zhang, George Q Zhang, Jiale Zhu
We show that unsymmetric BODIPY compounds with one, two, and three methyl groups can be synthesized easily and efficiently by the unsymmetric reaction method. Their steady state and time-resolved fluorescence properties are examined in solvents of different polarity. These compounds show high fluorescence quantum yields (0.87 to 1.0), long fluorescence lifetimes (5.89 to 7.40 ns), and small Stokes shift (199 to 443 cm-1 ). The methyl substitution exhibits influence on the UV-Vis absorption and fluorescence properties, such as the blue shift in emission and absorption spectra...
January 23, 2019: Journal of Fluorescence
Einstein Gnanatheepam, Udayakumar Kanniyappan, Koteeswaran Dornadula, Aruna Prakasarao, Ganesan Singaravelu
High incidence of oral cancer is primarily due to ongoing tobacco epidemic. In this work, synchronous luminescence spectroscopy (SLS) has been used to characterize and discriminate oral cancer tissue. Spectral deconvolution method is employed to compute the fluorescence intensity, peak wavelength, and full width half maxima for different endogenous fluorophores. The fluorescence measurements were made on 21 normal and 88 oral squamous cell carcinoma biopsy tissues. Besides, variations in relative concentration of collagen, NADH, and FAD, peak shifts and broadening of peaks are observed for tryptophan, NADH, and FAD, in oral cancer tissues indicating both biochemical and micro environmental changes at cellular level...
January 23, 2019: Journal of Fluorescence
Aslihan Yilmaz Obali, Delak Kamal Ali Ali, Halil Ismet Ucan
Tripodal receptors, N-1,3,5-tris[2-(ethylamino)ethyl]benzene-1,3,5-tricarboxylamide (L1), N-1,3,5-tris[2-(phenylamino)ethyl]benzene-1,3,5tricarboxylamide (L2) and highly fluorescent N-1,3,5-tris[2(naphthalene-2-ylamino)-ethyl]benzene-1,3,5,tricarboxyl-amid)) (L3) were synthesized by the reaction of 1,3,5-benzene-tricarbonylchloride and different amine groups originally. Sensitivity measurements were performed with the addition of Fe(II), Cu(II), Hg(II), Zn(II), Ni(II), Mn(II), Cd(II), Ga(III), Co(II), Yb(III), Cr(III) and Ag(I) metals to the receptor solutions...
January 19, 2019: Journal of Fluorescence
Marwa Mahmoud, Enas Abdel-Salam, Mahmoud Abou-Elmagd, Shehab Sallam
Schiff-bases of metformin with each of salicylaldehyde (HL1 ); 2,3-dihydroxybenzaldehyde (H2 L2 ); 2,4-dihydroxybenzaldehyde (H2 L3 ); 2,5-dihydroxybenzaldehyde (H2 L4 ); 3,4-dihydroxybenzaldehyde (H2 L5 ) and 2-hydroxynaphthaldehyde (HL6 ) and their complexes with Pr(III) were synthesized by template reaction. The complexes were characterized through elemental analysis, conductivity and magnetic moment measurements, IR, UV-Vis., fluorescence, GC-MS and XRD spectroscopy. The complexes exhibit a series of characteristic emission bands for Pr3+ ion in the 481-472 and 590-580 nm range with a 318-332 nm excitation source...
January 16, 2019: Journal of Fluorescence
Ravi Shrivastava
This paper reports the preparation of CaTiO3 doped with various concentrations of Dysprosium (II) using solid state reaction technique. X-ray diffraction patterns of the sample were taken. Observed XRD pattern was matched using software match2!. The pattern was matched significantly with the crystallographic open database card (COD - 96-101-1212) which is a standard card for CaTiO3 . This matching exhibited that, the prepared sample is cubic in structure with space group P m - 3 m (221). Photoluminescence (PL) studies of the samples were also done...
January 15, 2019: Journal of Fluorescence
G S Amitha, Vijisha K Rajan, K Muraleedharan, Suni Vasudevan
A novel 4,4'-fluoresceinoxy bisphthalonitrile FPN is synthesized from fluorescein and 4-nitrophthalonitrile by aromatic nucleophilic ipso nitro substitution reaction. The structure of FPN constitutes phthalonitrile-fluorescein-phthalonitrile, acceptor-donor-acceptor, A-D-A form and the solvatochromic study of newly synthesized compound FPN was done in hexane, cyclohexane, CHCl3 , DCM, DMF, acetonitrile, ethanol and in methanol. The aggregation behavior of FPN was investigated in good-poor solvent mixture DMF-water in various proportions and the molecule was found to be exhibiting Aggregation Induced Emission Enhancement AIEE for volume percentage of water beyond 50% with a significant hypsochromic shift of 70 nm in the emission maxima from 458 to 388 nm...
January 9, 2019: Journal of Fluorescence
Togiti Uday Kumar, Shweta Pawar, Amit Nag, Anupam Bhattacharya
This paper reports development of an iron sensor, 2-(3H-pyrrolo[2,3-c]quinolin-4-yl)aniline (APQ). The fluorophore facilitates micromolar detection of Fe3+ /Fe2+ in the presence of various cations, including well-known interfering cations Co2+ and Cu2+ by the process of fluorescence quenching. Graphical Abstract ᅟ.
January 8, 2019: Journal of Fluorescence
Gala Chapman, Gabor Patonay
We have synthesized and characterized of a series of single and multidye copolymerized nanoparticles with large to very large Stokes shifts (100 to 255 nm) for versatile applications as standalone or multiplexed probes in biological matrices. Nanoparticles were prepared via the Stöber method and covalently copolymerized with various combinations of three dyes, including one novel aminocyanine dye. Covalently encapsulated dyes exhibited no significant leakage from the nanoparticle matrix after more than 200 days of storage in ethanol...
January 7, 2019: Journal of Fluorescence
Pydisetti Gurunadha Rao, Birudaraju Saritha, T Siva Rao
A new rhodamine 6G based fluorescent and colorimetric chemosensor, containing N-methyl imidazole nucleus, for the selective detection of Hg2+ ion was designed and synthesized. The results of UV-Vis and fluorescence spectral study indicated that the receptor is selective and sensitive towards Hg2+ with no noticeable interference with other competitive metal ions. The addition of Hg2+ to the receptor induced a rapid color change to pink from colorless and the turn-on fluorescence response toward Hg2+ among different cations was studied...
January 6, 2019: Journal of Fluorescence
Diana M A Crista, Guilherme P C Mello, Olena Shevchuk, Ricardo M S Sendão, Eliana F C Simões, João M M Leitão, Luís Pinto da Silva, Joaquim C G Esteves da Silva
The selective fluorescence sensing of fructose was achieved by fluorescence quenching of the emission of hydrothermal-synthesized carbon quantum dots prepared by 3-hydroxyphenylboronic acid. Quantification of fructose was possible in aqueous solutions with pH of 9 (Limit of Detection LOD and Limit of Quantification LOQ of 2.04 and 6.12 mM), by quenching of the emission at 376 nm and excitation ~380 nm with a linearity range of 0-150 mM. A Stern-Volmer constant (KSV ) of 2.11 × 10-2  mM-1 was obtained, while a fluorescent quantum yield of 31% was calculated...
January 5, 2019: Journal of Fluorescence
Digambara Patra, Nadine Al Homsi, Sara Jaafar, Zeina Neouchy, Jomana Elaridi, Ali Koubeissi, Kamal H Bouhadir
The synthesis and spectroscopic characterization of novel nucleobase (adenine/thymine)-conjugated naphthalenediimides (NDIs), namely, NDI-AA, NDI-TT, and NDI-AT have been successfully achieved. NDI-AA, NDI-TT and NDI-AT have similar absorption in the 300-400 nm region. The effect of solvent on the absorption spectrum indicates aggregation, either through intermolecular π-σ interaction among the main chromophore or through intermolecular hydrogen bonding between adenine and adenine group. Addition of water does not assist hydrogen bond formation between thymine-thymine, rather increasing the polarity of the solvent encourages π-σ interaction among NDI-TTs...
January 4, 2019: Journal of Fluorescence
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