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Journal of Fluorescence

Qing-Hao Liu, Jin-Chun Guo, Hong-Yu Lu, Yan-Nan Guo, Hai-Bin Wang, Zhi-Yong Hu, Hong-Yan Liu, Dong-Liang, Li-Gong Chen
Derivatives of oxazine dyes were synthesized on mulitigram scales via efficient synthetic strategies. One practical route was selected to prepare compounds 6, 9 and 10, especially water-soluble compound 6 was obtained in better yield than reported, and compound 10 was insoluble in aqueous media in absence of phenolic-OH. Compounds 3 and 9 were found to be clear pH-dependent between pH = 4.0 and 10.0, and could be used as acid-base indicators to measure intracellular pH. Compounds 6, 9, 10 all have carboxylic acid functionalities, which could be activated and used to conjugate the dyes to biomolecules...
September 21, 2018: Journal of Fluorescence
Dong Lu, Yiping Tang, Yuhui Zheng
Alcoholic strength is a fundamental variable in industry production and its determination is crucial in technological developments. This study offers a novel strategy for fluorescent sensing of alcoholic content based on a terbium coordination complex. In pure water, the emissive compound displays blue luminescence. However, the addition of ethanol into the aqueous solution has induced the recovery of terbium green emissions. In another case, the achieved Eu(III)-phenanthroline complex shows high sensitivity to solvent polarity and the detection of trace amount of water can be realized through an "on-off" change with a low detection limit of 32...
September 17, 2018: Journal of Fluorescence
Sreetama Pal, Roger E Koeppe, Amitabha Chattopadhyay
WALPs are prototypical, α-helical transmembrane peptides that represent a consensus sequence for transmembrane segments of integral membrane proteins and serve as excellent models for exploring peptide-lipid interactions and hydrophobic mismatch in membranes. Importantly, the WALP peptides are in direct contact with the lipids. They consist of a central stretch of alternating hydrophobic alanine and leucine residues capped at both ends by tryptophans. In this work, we employ wavelength-selective fluorescence approaches to explore the intrinsic fluorescence of tryptophan residues in WALP23 in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membranes...
September 17, 2018: Journal of Fluorescence
Maria Sadia, Robina Naz, Jehangir Khan, Rizwan Khan
Copper being an essential nutrient; also pose a risk for human health in excessive amount. A simple and convenient method for the detection of trace amount of copper was employed using an optical probe R1 based on Schiff base. The probe was synthesized by Schiff base condensation of benzyl amine and 2-hydroxy-1-napthaldehyde and characterized by single X-ray diffraction, 1 H NMR and FTIR. By screening its fluorescence response in a mixture of DMSO and H2 O (20:80, v/v) R1 displayed a pronounced enhancement in fluorescence only upon treatment with copper...
September 15, 2018: Journal of Fluorescence
Ahmet T Uzumcu, Orhan Guney, Oguz Okay
Here we report the monitoring the instant creation of a new fluorescent signal (FS) aroused from a positively charged water-soluble fluorogenic probe, ethidium bromide (EtBr) in the presence of a radical initiator, ammonium persulfate (APS) and an accelerator, tetraethylmetilendiamine (TEMED) for evaluation of deoxyribonucleic acid (DNA) conformation. The results revealed that the occurred FS (λex  = 430 nm; λmax  = 525 nm) is a reduced form of EtBr (λex  = 480 nm; λmax  = 617 nm) and it is completely distinct from hydroethidine (λex  = 350 nm; λmax  = 430 nm), which is two-electron reduced form of EtBr...
September 15, 2018: Journal of Fluorescence
Prasad G Mahajan, Nilam C Dige, Balasaheb D Vanjare, Hussain Raza, Mubashir Hassan, Sung-Yum Seo, Seong-Karp Hong, Ki Hwan Lee
Herein, we design and synthesized new fluorescein based derivatives by insitu formation of fluorescein ester and further treated with corresponding hydrazide and amine to yield respective compounds i.e. FB1, FB2, FB3 and FB4. The spectral purity and characterization was done by using IR, NMR and Mass spectroscopies. The synthesized derivatives were examined for their photophysical properties by using variety of organic solvents and results were discussed in details. The structural diversity of synthesized compounds motivate us to evaluate these compounds for urease inhibition...
September 15, 2018: Journal of Fluorescence
Lenka Slusna, Ludovit Haizer, Eduard Jane, Dmitrij Bondarev, Vojtech Szocs, Milan Drzik, Eva Noskovicova, Dusan Lorenc, Dusan Velic
A novel copolymer poly(thiophene-2,5-diyl-2,5-di-n-octyloxycarbonyl-1,4-phenylene), denoted as P33, is introduced as potential material for photovoltaics, polymer light-emitting diodes, and/or organic transistors. P33 dissolved in chloroform is investigated by steady-state absorption, linear/non-linear fluorescence spectroscopies and time-resolved fluorescence spectroscopy. Molar extinction coefficient, fluorescence quantum yield, and singlet fluorescence lifetime of P33 are determined to be 18,315 M-1  cm-1 , 0...
September 14, 2018: Journal of Fluorescence
Balasaheb D Vanjare, Prasad G Mahajan, Mubashir Hassan, Hussain Raza, Sung-Yum Seo, Seong-Karp Hong, Ki Hwan Lee
A quinoline functionalized two novel fluorescent Schiff bases, N-(quinolin-2-ylmethylene) anthracen-1-amine (SB1) and 2-(quinolin-2-ylmethyleneamino) benzene thiol (SB2) were synthesized and confirmed by using 1 H NMR, IR and GC-MS techniques. The spectroscopic properties were examined by absorption spectroscopy and fluorescence spectroscopy. The absorption and fluorescence spectra of the probes (SB1 and SB2) were measured in a variety of solvents. Both the compounds were tested for urease inhibitory activity...
September 13, 2018: Journal of Fluorescence
Muhammad Ayaz, Muhammad Ayaz, Farman Ali, Aamer Saeed, Asma Khurshid, Ghulam Shabir, Tanveer Ahmad, Syed Asad Raza Kazmi, Hassan Ali Khan
Our present investigation aims at the synthesis and application of new, symmetric bridged bis-pyrazolone based acid dyes. The bis-pyrazolone compounds were accomplished from bis- hydrazine of 4,4'-Diaminostilbene-2,2'-disulfonic acid and ethyl acetoacetate. The bis-pyrazolones have been coupled with diazonium salts of o-hydroxyl aromatic amines which resulted in ligand dyes. The intermediate ligand dyes were treated with 3d transition metals to achieve the targeted metal complex acid dyes. The structures of investigated compounds were confirmed with the help of spectroscopic techniques...
September 7, 2018: Journal of Fluorescence
Muhammad Idrees, Rafida Bibi, Muhammad Naeem Khan
In this work fluorescence quenching of phenanthrene by heavy metal ions (Fe3+ , Cu2+ , Cr3+ Pb2+ , Ni2+ ) was studied in aqueous solution of sodium dodecyl sulphate (SDS). Fluorescence quenching was higher in lower SDS concentration and decreased with the increase in SDS concentration. Phenanthrene quenching by heavy metal ions were explained by Stern-Volmer equations and the Stern-Volmer constants were observed in the order Fe3+  > Cu2+  > Cr3+  > Pb2+  > Ni2+ respectively. Stern-Volmer constants reflect the sensitivity of the method for the studied metal ions...
September 5, 2018: Journal of Fluorescence
Bipin Rooj, Ankita Dutta, Sahidul Islam, Ujjwal Mandal
In this work carbon quantum dots (CQDs) are synthesized via a simple, low cost and as well as green way using tuberose (Polianthes tuberose L.) petals as the carbon source for the first time. We have not done any surface modification to the prepared CQDs although we directly employed this as fluorescent probe for the sensitive and selective detection of Fe2+ and Cu2+ ions. Both these ions drastically quench the emission intensity of the CQDs; in case of Cu2+ ions quenched CQDs EDTA results in regaining the fluorescence property but for Fe2+ ions quenched CQDs no such effect of EDTA is found...
September 5, 2018: Journal of Fluorescence
C Shobha Devi, B Thulasiram, Rajeshwar Rao Aerva, Penumaka Nagababu
Copper is a part of various enzymes and helps them to function properly. It can be effectively used to produce promising anticancer drugs and presently, many studies are being pursued worldwide on the development of copper-based complexes as potential anticancer drugs. Herein, we briefly discuss the importance of reactive oxygen species in biological applications and copper(II) complexes as anticancer drugs. The anti-angiogenic properties of mono-nuclear copper(II) complexes have been demonstrated by in vivo chick embryo angiogenesis analysis...
August 31, 2018: Journal of Fluorescence
Gözde Murat Saltan, Deniz Aykut Kıymaz, Ceylan Zafer, Haluk Dinçalp
In this paper, we report design and synthesis of novel low bandgap small molecules, indigo-benzimidazole (Tyr-3) and indigo-schiff base (Tyr-4) type acceptors. In these structures, tert-butoxycarbonyl (t-BOC) group has been attached to indigo nitrogen atom in order to increase the solubility. UV-vis absorption spectra of Tyr-3 and Tyr-4 dyes exhibit wide absorption bands ranging from 350 to 600 nm, indicating the relatively low bandgap giving around 2.07 eV for each. Excitation of both Tyr-3 and Tyr-4 dyes at 485 nm displays characteristic emission features of indigo moiety and also intramolecular charge transfer complex (ICT) related with their subunits...
August 30, 2018: Journal of Fluorescence
Naresh Kumar, Mahalingavelar Paramasivam, Jagdeep Kumar, Anamika Gusain, Prasanta Kumar Hota
Various electron donor and acceptor substituted (NO2 , CN, Cl, H, OCH3 , NH2 ) p-phenyl ethenyl-E- thiophenes (1-6) were synthesized and substituent dependent optical properties (dipole moment, transition dipole moment, oscillator strength, optical band gap, hyperpolarizability) were studied using Solvatochromism and Density functional theory. It is shown that thiophene acts as a weak electron donor in presence of an electron withdrawing p-phenyl substituent (NO2 , CN, Cl), whereas thiophene acts as a weak electron acceptor in presence of an electron donating p-phenyl substituent (OCH3 , NH2 )...
August 27, 2018: Journal of Fluorescence
Hoa T Hoang, Toni Haubitz, Michael U Kumke
In the study a dyad (C6 probe), constructed of two dyes with highly different hydrophobicities, was investigated by steady-state and time-resolved spectroscopic techniques in chloroform, methanol, and in phospholipid vesicles, respectively. The dyad was built on two dyes: the lipophilic benzo[a]pyrene (BaP) and the hydrophilic sulforhodamine B (SRB). The dyes were linked via a short, but flexible alkyl chain (six C-atoms). Based on their spectroscopic properties, BaP and SRB showed a very efficient non-radiative resonance energy transfer in solution...
August 25, 2018: Journal of Fluorescence
Amirhossein Fallah, Hayrettin Ozan Gülcan, Mustafa Gazi
The development of simple, environmental friendly, and cheap reagents with metal binding properties are quite important not only for the treatment of environmental pollution but also for their application in medicine. Within this study, for the first time, we displayed a natural chromen analogue, Urolithin B, as a simple, selective, fluorescent iron (III) sensing probe. Following the synthesis and structure identification studies, the selective metal binding property of the compound was displayed employing fluorescence techniques...
August 25, 2018: Journal of Fluorescence
Mihaela Homocianu, Alina M Ipate, Corneliu Hamciuc, Anton Airinei
The photophysical properties of the three 1,3,4-oxadiazole derivatives containing fluorene (Ox-FL); fluorene and phenolphtaleine (Ox-FL-FF); or fluorene and bisphenol A (Ox-FL-BPA) moieties in the main chain were investigated by the fluorescence and absorption spectroscopy in different solvents and in the solid state. The electronic absorption spectra included a strong absorption band located in the 270-395 nm region, with a maxima around at 302 nm. The fluorescence excitation spectra were also characterized by one broad band, appearing in the wavelength range of 220-340 nm...
August 25, 2018: Journal of Fluorescence
Keshav Kumar
The present work successfully shows the application of novel chemometric approach constraint randomised non-negative factor analysis (CRNNFA) for the analyses of the composite multidimensional fluorescence data sets. The CRNNFA involves the initialisation of the spectral variables in a constraint fashion thus ensures that algorithm does not wander with chemically and spectro-chemically irrelevant variables. The CRNNFA approach does not require that there must be pure variables for each fluorophores of the multifluorophoric mixture...
August 20, 2018: Journal of Fluorescence
Eran Zahavy, Shahar Rotem, David Gur, Ronit Aloni-Grinstein, Moshe Aftalion, Raphael Ber
Rapid antimicrobial susceptibility tests (ASTs) are essential tool for proper treatment of patients infected by Yersinia pestis (Y. pestis), the causative agent of plague, or for post-exposure prophylaxis of a population exposed to a naturally acquired or deliberately prepared resistant variant. The standard AST of Y. pestis is based on bacterial growth and requires 24-48 h of incubation in addition to the time required for prior isolation of a bacterial culture from the clinical or environmental sample, which may take an additional 24-48 h...
August 16, 2018: Journal of Fluorescence
Keshav Kumar
Excitation emission matrix fluorescence (EEMF) spectroscopy is a multiparametric fluorescence technique where the fluorescence intensity of a fluorophore is a function of excitation wavelength, emission wavelength and its concentration. The manual analysis of large volume of highly correlated EEMF data sets towards developing a calibration model for quantifying each fluorophores present in multifluorophoric mixtures is a difficult and time-consuming task. Over the years, Partial least square (PLS) algorithm has found its application towards providing swift and efficient analyses of large volumes of highly correlated spectral data sets...
August 16, 2018: Journal of Fluorescence
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