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Sample records for fluorescent conjugated pyrenes

  1. Coumarin–pyrene conjugate: Synthesis, structure and Cu-selective fluorescent sensing in mammalian kidney cells

    Energy Technology Data Exchange (ETDEWEB)

    Wani, Manzoor Ahmad [Department of Chemistry, Dr. H. S. Gour Central University Sagar, MP 470003 (India); Singh, Pankaj Kumar [Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Pandey, Rampal, E-mail: rpvimlesh@gmail.com [Department of Chemistry, Dr. H. S. Gour Central University Sagar, MP 470003 (India); Pandey, Mrituanjay D., E-mail: mdpandey@dhsgsu.ac.in [Department of Chemistry, Dr. H. S. Gour Central University Sagar, MP 470003 (India)

    2016-03-15

    In this work, we report a coumarin–pyrene based fluorescent probes (E)-7-(diethylamino)-3-((pyren-1-ylimino)methyl)-2H-chromen-2-one (1) and (E)-7-(diethylamino)-3-((pyren-1-ylmethylimino)methyl)-2H-chromen-2-one (2) for the selective detection of Cu{sup 2+} ion. Receptor 1 upon binding with Cu{sup 2+} exhibited substantial fluorescence quenching as a detection response. Probe 1 induces green fluorescence in a cell lines derived from monkey kidney tissue and subsequent quenching of fluorescence in these cells manifest that 1 can probably be used as a potential fluorescent sensor for the detection of Cu{sup 2+} in biological samples too. However, 2 does not reveal any significant fluorescence change in presence of different metal ions. It is assumed that conjugation might be accountable for the discrete fluorescent behavior of 1 and 2.

  2. A quencher-free molecular beacon design based on pyrene excimer fluorescence using pyrene-labeled UNA (unlocked nucleic acid)

    DEFF Research Database (Denmark)

    Karlsen, Kasper Kannegård; Okholm, Anders Hauge; Kjems, Jørgen

    2013-01-01

    A quencher-free molecular beacon capable of generating pyrene excimer fluorescence has been constructed using strategically positioned pyrene-UNA monomers. Hybridization of a fully complementary RNA target was accompanied by a pyrene excimer emission increase of more than 900%, and detection of RNA...

  3. Thermal properties and physicochemical behavior in aqueous solution of pyrene-labeled poly(ethylene glycol-polylactide conjugate

    Directory of Open Access Journals (Sweden)

    Chen WL

    2015-04-01

    Full Text Available Wei-Lin Chen,1,2 Yun-Fen Peng,1,3 Sheng-Kuo Chiang,1 Ming-Hsi Huang1–3 1National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan; 2Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan; 3PhD Program in Tissue Engineering and Regenerative Medicine, National Chung Hsing University, Taichung, Taiwan Abstract: A fluorescence-labeled bioresorbable polymer was prepared by a coupling reaction of poly(ethylene glycol-polylactide (PEG-PLA with carboxyl pyrene, using N,N’-diisopropylcarbodiimide/1-hydroxy-7-azabenzotriazole (DIC/HOAt as a coupling agent and 4-dimethylaminopyridine (DMAP as a catalyst. The obtained copolymer, termed PEG-PLA-pyrene, was characterized using various analytical techniques, such as gel permeation chromatography (GPC, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS, proton nuclear magnetic resonance (1H-NMR, infrared spectroscopy (IR, differential scanning calorimetry (DSC, and thermogravimetric analysis (TGA, to identify the molecular structure and to monitor the thermal property changes before and after the reaction. The presence of a pyrene moiety at the end of polylactide (PLA did not alter the crystallization ability of the poly(ethylene glycol (PEG blocks, indicating that the conjugate preserved the inherent thermal properties of PEG-PLA. However, the presence of PEG-PLA blocks strongly reduced the melting of pyrene, indicating that the thermal characteristics were sensitive to PEG-PLA incorporation. Regarding the physicochemical behavior in aqueous solution, a higher concentration of PEG-PLA-pyrene resulted in a higher ultraviolet-visible (UV-vis absorbance and fluorescence emission intensity. This is of great interest for the use of this conjugate as a fluorescence probe to study the in vivo distribution as well as the internalization and intracellular localization of polymeric micelles

  4. Pyrene-modified unlocked nucleic acids: synthesis, thermodynamic studies, and fluorescent properties

    DEFF Research Database (Denmark)

    Karlsen, Kasper K; Pasternak, Anna; Jensen, Troels B

    2012-01-01

    -UNA modifications were studied. It was found that incorporation of pyrene-UNA monomers increased duplex stability relative to UNA monomers, and thermodynamic studies revealed significant mismatch discriminative capabilities of the pyrene-UNA modified oligonucleotides. Furthermore, the steady-state fluorescence...... emission intensities of pyrene-UNA modified oligonucleotides were increased upon hybridization to DNA, which to the best of our knowledge is unprecedented for an acyclic pyrene modification in DNA. Interestingly, pyrene excimer emission was observed for single-stranded oligonucleotides containing three...

  5. A pyrene-benzthiazolium conjugate portraying aggregation induced emission, a ratiometric detection and live cell visualization of HSO_3"−

    International Nuclear Information System (INIS)

    Diwan, Uzra; Kumar, Virendra; Mishra, Rakesh K.; Rana, Nishant Kumar; Koch, Biplob; Singh, Manish Kumar; Upadhyay, K.K.

    2016-01-01

    The present study deals with the photophysical property of a pyrene-benzthiazolium conjugate R1, as a strong intramolecular charge transfer (ICT) probe exhibiting long wavelength emission in the red region. Unlike traditional planar polyaromatic hydrocarbons whose aggregation generally quenches the light emission, the pyrene based R1 was found to display aggregation-induced emission (AIE) property along with simultaneous increase in its quantum yield upon increasing the water content of the medium. The R1 exhibits high specificity towards HSO_3"−/SO_3"2"− by interrupting its own ICT producing there upon a large ratiometric blue shift of ∼220 nm in its emission spectrum. The lowest detection limit for the above measurement was found to be 8.90 × 10"−"8 M. The fluorescent detection of HSO_3"− was also demonstrated excellently by test paper strip and silica coated TLC plate incorporating R1. The live cell imaging of HSO_3"− through R1 in HeLa cells was studied using fluorescence microscopic studies. The particle size and morphological features of R1 and R1-HSO_3"− aggregates in aqueous solution were characterized by DLS along with SEM analysis.- Highlights: • A pyrene-benzthiazolium conjugate probe (R1) itself showed interesting phenomenon of an aggregation-induced emission (AIE). • R1 emits in the red channel and effectively utilized as a colorimetric and ratiometric fluorescent sensor for HSO_3"−. • The nano-dimensional spherical particles of R1 got enlarged upon its interaction with the HSO_3"−. • R1 can efficiently stain HSO_3"− in live cells and can be used for the on-spot detection of the same.

  6. Bis-pyrene-modified unlocked nucleic acids: synthesis, hybridization studies, and fluorescent properties

    DEFF Research Database (Denmark)

    Perlíková, Pavla; Ejlersen, Maria; Langkjaer, Niels

    2014-01-01

    Efficient synthesis of a building block for the incorporation of a bis-pyrene-modified unlocked nucleic acid (UNA) into oligonucleotides (DNA*) was developed. The presence of bis-pyrene-modified UNA within a duplex leads to duplex destabilization that is more profound in DNA*/RNA and less distinc......)uracil:pyrene exciplex emission in the single-stranded form. Such fluorescent properties enable the application of bis-pyrene-modified UNA in the development of fluorescence probes for DNA/RNA detection and for detection of deletions at specific positions....

  7. Synthesis, fluorescence properties and the promising cytotoxicity of pyrene-derived aminophosphonates.

    Science.gov (United States)

    Lewkowski, Jarosław; Rodriguez Moya, Maria; Wrona-Piotrowicz, Anna; Zakrzewski, Janusz; Kontek, Renata; Gajek, Gabriela

    2016-01-01

    A large series of variously substituted amino(pyren-1-yl)methylphosphonic acid derivatives was synthesized using a modified aza-Pudovik reaction in 20-97% yields. The fluorescence properties of the obtained compounds were investigated revealing that N-alkylamino(pyren-1-yl)methylphosphonic derivatives are stronger emissive compounds than the corresponding N-aryl derivatives. N-Benzylamino(pyren-1-yl)methylphosphonic acid displayed strong fluorescence (ΦF = 0.68) in phosphate-buffered saline (PBS). The influence of a series of derivatives on two colon cancer cell lines HT29 and HCT116 was also investigated. The most promising results were obtained for N-(4-methoxyphenyl)amino(pyren-1-yl)methylphosphonate, which was found to be cytotoxic for the HCT116 cancer cell line (IC50 = 20.8 μM), simultaneously showing weak toxicity towards normal lymphocytes (IC50 = 230.8 µM).

  8. Pyrene-Phosphonate Conjugate: Aggregation-Induced Enhanced Emission, and Selective Fe3+ Ions Sensing Properties

    Directory of Open Access Journals (Sweden)

    Sachin D. Padghan

    2017-08-01

    Full Text Available A new pyrene-phosphonate colorimetric receptor 1 has been designed and synthesized in a one-step process via amide bond formation between pyrene butyric acid chloride and phosphonate-appended aniline. The pyrene-phosphonate receptor 1 showed aggregation-induced enhanced emission (AIEE properties in water/acetonitrile (ACN solutions. Dynamic light scattering (DLS characterization revealed that the aggregates of receptor 1 at 80% water fraction have an average size of ≈142 nm. Field emission scanning electron microscopy (FE-SEM analysis confirmed the formation of spherical aggregates upon solvent evaporation. The sensing properties of receptor 1 were investigated by UV-vis, fluorescence emission spectroscopy, and other optical methods. Among the tested metal ions, receptor 1 is capable of recognizing the Fe3+ ion selectively. The changes in spectral measurements were explained on the basis of complex formation. The composition of receptor 1 and Fe3+ ions was determined by using Job’s plot and found to be 1:1. The receptor 1–Fe3+ complex showed a reversible UV-vis response in the presence of EDTA.

  9. A pyrene-benzthiazolium conjugate portraying aggregation induced emission, a ratiometric detection and live cell visualization of HSO{sub 3}{sup −}

    Energy Technology Data Exchange (ETDEWEB)

    Diwan, Uzra; Kumar, Virendra [Department of Chemistry (Centre of Advanced Study), Faculty of Science, Banaras Hindu University, Varanasi, Uttar Pradesh 221005 (India); Mishra, Rakesh K. [Photosciences and Photonics, Chemical Sciences and Technology Division, CSIR–National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019 (India); Rana, Nishant Kumar; Koch, Biplob; Singh, Manish Kumar [Department of Zoology (Centre of Advanced Study), Faculty of Science, Banaras Hindu University, Varanasi 221005 (India); Upadhyay, K.K., E-mail: drkaushalbhu@yahoo.co.in [Department of Chemistry (Centre of Advanced Study), Faculty of Science, Banaras Hindu University, Varanasi, Uttar Pradesh 221005 (India)

    2016-07-27

    The present study deals with the photophysical property of a pyrene-benzthiazolium conjugate R1, as a strong intramolecular charge transfer (ICT) probe exhibiting long wavelength emission in the red region. Unlike traditional planar polyaromatic hydrocarbons whose aggregation generally quenches the light emission, the pyrene based R1 was found to display aggregation-induced emission (AIE) property along with simultaneous increase in its quantum yield upon increasing the water content of the medium. The R1 exhibits high specificity towards HSO{sub 3}{sup −}/SO{sub 3}{sup 2−} by interrupting its own ICT producing there upon a large ratiometric blue shift of ∼220 nm in its emission spectrum. The lowest detection limit for the above measurement was found to be 8.90 × 10{sup −8} M. The fluorescent detection of HSO{sub 3}{sup −} was also demonstrated excellently by test paper strip and silica coated TLC plate incorporating R1. The live cell imaging of HSO{sub 3}{sup −} through R1 in HeLa cells was studied using fluorescence microscopic studies. The particle size and morphological features of R1 and R1-HSO{sub 3}{sup −} aggregates in aqueous solution were characterized by DLS along with SEM analysis.- Highlights: • A pyrene-benzthiazolium conjugate probe (R1) itself showed interesting phenomenon of an aggregation-induced emission (AIE). • R1 emits in the red channel and effectively utilized as a colorimetric and ratiometric fluorescent sensor for HSO{sub 3}{sup −}. • The nano-dimensional spherical particles of R1 got enlarged upon its interaction with the HSO{sub 3}{sup −}. • R1 can efficiently stain HSO{sub 3}{sup −} in live cells and can be used for the on-spot detection of the same.

  10. Bis-Pyrene-Modified Unlocked Nucleic Acids: Synthesis, Hybridization Studies, and Fluorescent Properties

    Czech Academy of Sciences Publication Activity Database

    Perlíková, Pavla; Ejlersen, M.; Langkjaer, N.; Wengel, J.

    2014-01-01

    Roč. 9, č. 9 (2014), s. 2120-2127 ISSN 1860-7179 Grant - others:European Research Council(XE) FP7-268776 Institutional support: RVO:61388963 Keywords : fluorescence * nucleic acid hybridization * oligonucleotides * pyrenes * unlocked nucleic acids Subject RIV: CC - Organic Chemistry Impact factor: 2.968, year: 2014

  11. Unlocked nucleic acids with a pyrene-modified uracil: Synthesis, hybridization studies, fluorescent properties and i-motif stability

    DEFF Research Database (Denmark)

    Perlíková, P.; Karlsen, K.K.; Pedersen, E.B.

    2014-01-01

    The synthesis of two new phosphoramidite building blocks for the incorporation of 5-(pyren-1-yl)uracilyl unlocked nucleic acid (UNA) monomers into oligonucleotides has been developed. Monomers containing a pyrene-modified nucleobase component were found to destabilize an i-motif structure at pH 5...... intensities upon hybridization to DNA or RNA. Efficient quenching of fluorescence of pyrene-modified UNA monomers was observed after formation of i-motif structures at pH 5.2. The stabilizing/destabilizing effect of pyrene-modified nucleic acids might be useful for designing antisense oligonucleotides...

  12. Pyrene conjugation and spectroscopic analysis of hydroxypropyl methylcellulose compounds successfully demonstrated a local dielectric difference associated with in vivo anti-prion activity.

    Directory of Open Access Journals (Sweden)

    Kenta Teruya

    Full Text Available Our previous study on prion-infected rodents revealed that hydroxypropyl methylcellulose compounds (HPMCs with different molecular weights but similar composition and degree of substitution have different levels of long-lasting anti-prion activity. In this study, we searched these HPMCs for a parameter specifically associated with in vivo anti-prion activity by analyzing in vitro chemical properties and in vivo tissue distributions. Infrared spectroscopic and thermal analyses revealed no differences among HPMCs, whereas pyrene conjugation and spectroscopic analysis revealed that the fluorescence intensity ratio of peak III/peak I correlated with anti-prion activity. This correlation was more clearly demonstrated in the anti-prion activity of the 1-year pre-infection treatment than that of the immediate post-infection treatment. In addition, the intensity ratio of peak III/peak I negatively correlated with the macrophage uptake level of HPMCs in our previous study. However, the in vivo distribution pattern was apparently not associated with anti-prion activity and was different in the representative tissues. These findings suggest that pyrene conjugation and spectroscopic analysis are powerful methods to successfully demonstrate local dielectric differences in HPMCs and provide a feasible parameter denoting the long-lasting anti-prion activity of HPMCs in vivo.

  13. Novel (Phenylethynyl)pyrene-LNA Constructs for Fluorescence SNP Sensing in Polymorphic Nucleic Acid Targets

    DEFF Research Database (Denmark)

    Astakhova, Irina Kira; Samokhina, Evgeniya; Babu, B Ravindra

    2012-01-01

    We describe fluorescent oligonucleotide probes labeled with novel (phenylethynyl)pyrene dyes attached to locked nucleic acids. Furthermore, we prove the utility of these probes for the effective detection of single-nucleotide polymorphisms in natural nucleic acids. High-affinity hybridization......DNA and RNA gene fragments. Target sequences were obtained by analysis of 200 clinical samples from patients currently receiving anti-HIV/AIDS combination therapy at the Russian Federal AIDS Center. Using these fluorescent oligonucleotides, we were able to detect the target mutation despite all the challenges...

  14. A Fluorescent Thermometer Based on a Pyrene-Labeled Thermoresponsive Polymer

    Directory of Open Access Journals (Sweden)

    Ulrich S. Schubert

    2010-08-01

    Full Text Available Thermoresponsive polymers that undergo a solubility transition by variation of the temperature are important materials for the development of ‘smart’ materials. In this contribution we exploit the solubility phase transition of poly(methoxy diethylene glycol methacrylate, which is accompanied by a transition from hydrophilic to hydrophobic, for the development of a fluorescent thermometer. To translate the polymer phase transition into a fluorescent response, the polymer was functionalized with pyrene resulting in a change of the emission based on the microenvironment. This approach led to a soluble polymeric fluorescent thermometer with a temperature range from 11 °C to 21 °C. The polymer phase transition that occurs during sensing is studied in detail by dynamic light scattering.

  15. Estimation of AOT and SDS CMC in a methanol using conductometry, viscometry and pyrene fluorescence spectroscopy methods

    Science.gov (United States)

    Mitsionis, Anastasios I.; Vaimakis, Tiverios C.

    2012-09-01

    Critical micelle concentration (CMC) of two anionic surfactants in methanol was estimated using conductometry, viscometry and pyrene fluorescence spectroscopy methods. The surfactants used, were sodium bis(2-ethylhexyl) sulfosuccinate (Aerosol-OT, AOT) and sodium dodecyl sulfate (SDS) dispersed in pure methanol. The CMC determination was evaluated in room temperature. The results have shown nearly similar concentrations.

  16. Long Range Polymer Chain Dynamics of Highly Flexible Polysiloxane in Solution Probed by Pyrene Excimer Fluorescence

    Directory of Open Access Journals (Sweden)

    Janine L. Thoma

    2018-03-01

    Full Text Available A poly(dimethylsiloxane-co-(3-aminopropylmethylsiloxane polymer (PDMS with 20.3 mol % of (3-aminopropylmethyl siloxane monomer has been labeled randomly with 1-pyreneacetyl groups to generate a series of polysiloxanes (Py-PDMS with pyrenyl contents ranging from 0.7 mol % to 5.2 mol % of the total number of structural units. The remainder of the amino groups were acetylated to avoid intra-chain quenching of the excited singlet states of pyrene via exciplex formation with free amino groups while allowing the formation of excimers to proceed. The fluorescence spectra and temporal decays of the Py-PDMS samples were acquired in tetrahydrofuran (THF, N,N-dimethylformamide (DMF, and dioxane. blob, the average rate constant for intra-chain pyrene excimer formation, was determined from the analysis of the fluorescence decays. blob was found to equal 1.16 (±0.13 × 109, 1.14 (±0.12 × 109, and 0.99 (±0.10 × 109 s−1 in THF, DMF, and dioxane, respectively, at room temperature. They are the largest values found to date for any polymeric backbone in these solvents. The qualitative relationship found here between blob and the chemical structures of the polymers indicates that the luminescence characteristics of randomly labeled polymers is a very useful method to probe the long range dynamics of chains of almost any polymer that is amenable to substitution by a lumophore.

  17. IRDye78 Conjugates for Near-Infrared Fluorescence Imaging

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    Atif Zaheer

    2002-10-01

    Full Text Available The detection of human malignancies by near-infrared (NIR fluorescence will require the conjugation of cancer-specific ligands to NIR fluorophores that have optimal photoproperties and pharmacokinetics. IRDye78, a tetra-sulfonated heptamethine indocyanine NIR fluorophore, meets most of the criteria for an in vivo imaging agent, and is available as an N-hydroxysuccinimide ester for conjugation to low-molecular-weight ligands. However, IRDye78 has a high charge-to-mass ratio, complicating purification of conjugates. It also has a potentially labile linkage between fluorophore and ligand. We have developed an ion-pairing purification strategy for IRDye78 that can be performed with a standard C18 column under neutral conditions, thus preserving the stability of fluorophore, ligand, and conjugate. By employing parallel evaporative light scatter and absorbance detectors, all reactants and products are identified, and conjugate purity is maximized. We describe reversible and irreversible conversions of IRDye78 that can occur during sample purification, and describe methods for preserving conjugate stability. Using seven ligands, spanning several classes of small molecules and peptides (neutral, charged, and/or hydrophobic, we illustrate the robustness of these methods, and confirm that IRDye78 conjugates so purified retain bioactivity and permit NIR fluorescence imaging of specific targets.

  18. Chemical sensing of Benzo[a]pyrene using Corchorus depressus fluorescent flavonoids.

    Science.gov (United States)

    Ahmad, Wajiha; Rana, Nosheen Fatima; Riaz, Sundus; Ahmad, Nasir Mehmood; Hameed, Maryam; Naeem, Ayesha; Tahir, Rabbiya

    2018-04-01

    Plant phytochemicals, such as flavonoids are in use for the development of optical biosensor. Benzo[a]pyrene (B[a]P), is a pervasive environmental and dietary carcinogen. A fluorescent assay is developed using plant isolated flavonoid for the detection of B[a]P. High content saponins are excluded from the flavonoid-containing methanolic extract of Corchorus depressus by implying reduction of silver ions by saponins resulting in formation of silver nanoparticles. Isolated plant flavonoids are used to develop a spectrofluorometric assay for the detection of B[a]P. Decrease in the flavonoid fluorescence intensity by B[a]P is found to be based on both static and dynamic quenching. Specificity of the assay for B[a]P was tested for other carcinogens belonging to different classes of compounds. Flavonoids-mediated sensing can be implied for the development of new generation of nanoparticle-based biosensors that can be more sensitive and less susceptible to external factors, such as temperature and humidity.

  19. Magnetic modulation of exciplex fluorescence of pyrene solutions with azacrown-ether excess in the presence of ions of alkali and alkaline earth metals

    International Nuclear Information System (INIS)

    Borisenko, V.N.; Petrov, N.Kh.; Gromov, S.P.; Alfimov, M.V.

    1997-01-01

    Photoexcitation of polar pyrene solutions with excess of phenylaza-15-crown-5 as a donor results to intermolecular electron transfer with formation of ion-radical pairs, recombination of which produces fluorescent exciplex. Charge exchange between molecules of crown ether and its cation-radicals is practically absent at that. Magnetic effect, observed for fluorescence, decreases, when adding diamagnetic lithium and calcium ions to exiplex pyrene/crown-ether system. This can be explained by formation of paramagnetic complexes. 15 refs., 5 figs

  20. Recombinogenic engineering of conjugative plasmids with fluorescent marker cassettes

    DEFF Research Database (Denmark)

    Reisner, A.; Molin, Søren; Zechner, E.L.

    2002-01-01

    An efficient approach for the insertion of fluorescent marker genes with sequence specificity into conjugative plasmids in Escherichia coli is described. For this purpose, homologous recombination of linear double-stranded targeting DNA was mediated by the bacteriophage lambda recombination...... resistance genes and fluorescent markers. The choice of 5' non-homologous extensions in primer pairs used for amplifying the marker cassettes determines the site specificity of the targeting DNA. This methodology is applicable to the modification of all plasmids that replicate in E coli and is not restricted...

  1. Novel poly(triphenylamine-alt-fluorene) with asymmetric hexaphenylbenzene and pyrene moieties: synthesis, fluorescence, flexible near-infrared electrochromic devices and theoretical investigation

    KAUST Repository

    Wang, Po-I.

    2016-01-13

    © The Royal Society of Chemistry 2016. In this study, a new triphenylamine-alt-fluorene conjugated copolymer, HPBPYFL6, with hexaphenylbenzene (HPB) and pyrene as asymmetrical pendant groups was synthesized via Suzuki coupling polymerization. The conjugated polymer had a weight-average molecular weight of 5.8 × 104 g mol-1 with a polydispersity index of 2.5 characterized by gel permeation chromatography (GPC). HPBPYFL6 showed good solubility in common organic solvents such as NMP, THF, toluene and dichloromethane at 25°C. In addition, HPBPYFL6 possessed a high glass transition temperature of 260°C and a 10% weight-loss temperature of 503°C in nitrogen. HPBPYFL6 bearing a pyrene moiety had a solvatochromic fluorescence shift from a green to an orange emission as the polarity of the solvent increased. Cyclic voltammetry of HPBPYFL6 films cast onto indium-tin oxide-coated glass (ITO-glass) exhibited two oxidation redox couples at an E1/2 value of 0.82 and 1.17 V versus Ag/Ag+ in an acetonitrile solution. The HPBPYFL6 film on graphene-coated PET had an E1/2 value of 0.24 and 1.12 V. Conjugated polymer films exhibited reversible electrochromic behaviour with a colour change from pale yellow to deep blue upon electrochemical oxidation and high absorbance in the near-infrared (NIR) region. The switching and bleaching times were 5.16 s and 3.12 s for 1231 nm and were 3.30 s and 3.74 s for 1030 nm of HPBPYFL6 on ITO-glass. The strong NIR electrochromic absorbance of HPBPYFL6 was attributed to intervalence charge transfer by the incorporation of the HPB moiety. This phenomenon was confirmed by chemical oxidation as the oxidant contents increased in the solution state. Furthermore, the electrochromic mechanism was interpreted by DFT calculation and the simulated NIR electrochromic spectra of model compound HPBPYFL are in good agreement with the experimental data.

  2. Photochemical products causing fluorescence enhancement for 6H-benzo[cd]pyren-6-one in de-aerated and pre-irradiated solutions

    Energy Technology Data Exchange (ETDEWEB)

    Yagishita, M., E-mail: yagishita.mayuko@nies.go.jp [Department of Environmental Science, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510 (Japan); National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba-City, Ibaraki 305-8506 (Japan); Nakajima, D. [National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba-City, Ibaraki 305-8506 (Japan); Ohshima, S. [Department of Environmental Science, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510 (Japan)

    2016-11-15

    Polycyclic aromatic ketones emit very weak fluorescence, but their fluorescence is significantly enhanced by about one hundred times after preliminary irradiation of their degassed solution. To investigate the mechanism of such fluorescence enhancement, liquid chromatography/time-of-flight mass spectrometry measurements were performed for degassed methanol, ethanol, and acetonitrile solutions of 6H-benzo[cd]pyren-6-one (naphthanthrone), in which fluorescence enhancement had been induced. As a result, two kinds of photochemical products were identified as the substance causing fluorescence enhancement: they were produced by dehydrogenation and dehydration of adducts of a solvent molecule to naphthanthrone. On the basis of the findings, the mechanism of the fluorescence enhancement of naphthanthrone was discussed. Fluorescence enhancement; 6H-benzo[cd]pyren-6-one; Polycyclic aromatic ketones; Liquid chromatography-mass spectrometry; Photochemical reaction.

  3. Photochemical products causing fluorescence enhancement for 6H-benzo[cd]pyren-6-one in de-aerated and pre-irradiated solutions

    International Nuclear Information System (INIS)

    Yagishita, M.; Nakajima, D.; Ohshima, S.

    2016-01-01

    Polycyclic aromatic ketones emit very weak fluorescence, but their fluorescence is significantly enhanced by about one hundred times after preliminary irradiation of their degassed solution. To investigate the mechanism of such fluorescence enhancement, liquid chromatography/time-of-flight mass spectrometry measurements were performed for degassed methanol, ethanol, and acetonitrile solutions of 6H-benzo[cd]pyren-6-one (naphthanthrone), in which fluorescence enhancement had been induced. As a result, two kinds of photochemical products were identified as the substance causing fluorescence enhancement: they were produced by dehydrogenation and dehydration of adducts of a solvent molecule to naphthanthrone. On the basis of the findings, the mechanism of the fluorescence enhancement of naphthanthrone was discussed. Fluorescence enhancement; 6H-benzo[cd]pyren-6-one; Polycyclic aromatic ketones; Liquid chromatography-mass spectrometry; Photochemical reaction

  4. Fluorescent nanodiamond-bacteriophage conjugates maintain host specificity.

    Science.gov (United States)

    Trinh, Jimmy T; Alkahtani, Masfer H; Rampersaud, Isaac; Rampersaud, Arfaan; Scully, Marlan; Young, Ryland F; Hemmer, Philip; Zeng, Lanying

    2018-06-01

    Rapid identification of specific bacterial strains within clinical, environmental, and food samples can facilitate the prevention and treatment of disease. Fluorescent nanodiamonds (FNDs) are being developed as biomarkers in biology and medicine, due to their excellent imaging properties, ability to accept surface modifications, and lack of toxicity. Bacteriophages, the viruses of bacteria, can have exquisite specificity for certain hosts. We propose to exploit the properties of FNDs and phages to develop phages conjugated with FNDs as long-lived fluorescent diagnostic reagents. In this study, we develop a simple procedure to create such fluorescent probes by functionalizing the FNDs and phages with streptavidin and biotin, respectively. We find that the FND-phage conjugates retain the favorable characteristics of the individual components and can discern their proper host within a mixture. This technology may be further explored using different phage/bacteria systems, different FND color centers and alternate chemical labeling schemes for additional means of bacterial identification and new single-cell/virus studies. © 2018 Wiley Periodicals, Inc.

  5. Charge recombination process in X-ray irradiated pyrene-doped polystyrene as studied by optically detected electron spin resonance and magnetic field dependence of the recombination fluorescence

    International Nuclear Information System (INIS)

    Okazaki, Masaharu; Tai, Yutaka; Toriyama, Kazumi

    1993-01-01

    The optically-detected ESR (ODESR) spectrum and magnetic field dependence on recombination fluorescence were observed for X-ray irradiated pyrene-doped polystyrene at temperatures of 242-348 K. The ODESR intensity as a function of the pyrene concentration, 0.1-8.9 wt%, showed an unusual minimum at about 1.0%. Two phases were separated in the magnetic field dependence of the fluorescence: one was sharp and saturates at fields of over 50 mT, while the other was broad with a dip at around 60-150 mT. The cause of this dip was naturally attributed to the ST -1 level crossing. The sharp magnetic field effect also showed a minimum at around a concentration of 1.0 wt%. These novel findings have been interpreted using a recombination model modified from the previous one for pyrene-doped ethylene-propylene rubber and polyethylene. The essential points of the present model are: (1) although electron hopping within the polystyrene molecule is rapid, electron transfer at the last step of recombination between the polystyrene anion and the pyrene cation proceeds at a moderate rate; (2) the hole-transfer rate in the polymer chain is moderate; (3) electron hopping between the doped pyrene molecules is very much dependent on the concentration; (4) hole hopping between the pyrenes is inhibited. (author)

  6. A Pyrene- and Phosphonate-Containing Fluorescent Probe as Guest Molecule in a Host Polymer Matrix

    Directory of Open Access Journals (Sweden)

    Jacqueline Marchand-Brynaert

    2013-02-01

    Full Text Available New host-guest materials have been prepared by incorporation of a home-made organic probe displaying a pyrene motif and a phosphonate function into a regular amphiphilic copolymer. Using powder X-Ray diffraction, photoluminescence and FT-IR spectroscopy, we have been able to study the non-covalent interactions between the host matrix and the guest molecule in the solid state. Interestingly, we have shown that the matrix directs the guest spatial localization and alters its properties. Thanks to the comparison of pyrene vs. N-pyrenylmaleimide derivatives, the influence of the chemical nature of the guest molecules on the non-covalent interactions with the host have been studied. In addition, using polyethylene glycol as a reference host, we have been able to evidence a true matrix effect within our new insertion materials. The phosphonated guest molecule appears to be a novel probe targeting the hydrophilic domain of the host copolymer.

  7. Flow-through sensor based on derivative synchronous fluorescence spectrometry for the simultaneous determination of pyrene, benzo(e)pyrene and benzo(ghi)perylene in water

    Energy Technology Data Exchange (ETDEWEB)

    Canizares, P. [Cordoba Univ. (Spain). Dept. of Anal. Chem.; Luque de Castro, M.D. [Cordoba Univ. (Spain). Dept. of Anal. Chem.

    1996-02-01

    A flow-through/first derivative synchronous spectrofluorimetric sensor for the determination of PAH has been described. This sensor has been used for the simultaneous determination of PAH mixtures (pyrene, benzo(e)pyrene and benzo(ghi)perylene). Linear calibration ranges between 10 and 500 ng/ml with acceptable precision (repeatability, expressed as relative standard deviation, smaller than 4.6%, and sampling frequency of 12 h{sup -1}) have been obtained. The method has been applied to the determination of the target analytes in spiked water samples with excellent results (recoveries between 94 and 108%). (orig.)

  8. Evaluation of chemical fluorescent dyes as a protein conjugation partner for live cell imaging.

    Directory of Open Access Journals (Sweden)

    Yoko Hayashi-Takanaka

    Full Text Available To optimize live cell fluorescence imaging, the choice of fluorescent substrate is a critical factor. Although genetically encoded fluorescent proteins have been used widely, chemical fluorescent dyes are still useful when conjugated to proteins or ligands. However, little information is available for the suitability of different fluorescent dyes for live imaging. We here systematically analyzed the property of a number of commercial fluorescent dyes when conjugated with antigen-binding (Fab fragments directed against specific histone modifications, in particular, phosphorylated H3S28 (H3S28ph and acetylated H3K9 (H3K9ac. These Fab fragments were conjugated with a fluorescent dye and loaded into living HeLa cells. H3S28ph-specific Fab fragments were expected to be enriched in condensed chromosomes, as H3S28 is phosphorylated during mitosis. However, the degree of Fab fragment enrichment on mitotic chromosomes varied depending on the conjugated dye. In general, green fluorescent dyes showed higher enrichment, compared to red and far-red fluorescent dyes, even when dye:protein conjugation ratios were similar. These differences are partly explained by an altered affinity of Fab fragment after dye-conjugation; some dyes have less effect on the affinity, while others can affect it more. Moreover, red and far-red fluorescent dyes tended to form aggregates in the cytoplasm. Similar results were observed when H3K9ac-specific Fab fragments were used, suggesting that the properties of each dye affect different Fab fragments similarly. According to our analysis, conjugation with green fluorescent dyes, like Alexa Fluor 488 and Dylight 488, has the least effect on Fab affinity and is the best for live cell imaging, although these dyes are less photostable than red fluorescent dyes. When multicolor imaging is required, we recommend the following dye combinations for optimal results: Alexa Fluor 488 (green, Cy3 (red, and Cy5 or CF640 (far-red.

  9. Photosensitizer conjugated iron oxide nanoparticles for simultaneous in vitro magneto-fluorescent imaging guided photodynamic therapy.

    Science.gov (United States)

    Nafiujjaman, Md; Revuri, Vishnu; Nurunnabi, Md; Cho, Kwang Jae; Lee, Yong-Kyu

    2015-04-04

    In this study, photosensitizer conjugated iron oxide nanoparticles were strategically designed and prepared for simultaneous PDT and dual-mode fluorescence/MR imaging. The MRI contrast agent Fe3O4 was modified by APTES to functionalize the surface and further to link with heparin-pheophorbide-A conjugates.

  10. Bio-degradable highly fluorescent conjugated polymer nanoparticles for bio-medical imaging applications.

    Science.gov (United States)

    Repenko, Tatjana; Rix, Anne; Ludwanowski, Simon; Go, Dennis; Kiessling, Fabian; Lederle, Wiltrud; Kuehne, Alexander J C

    2017-09-07

    Conjugated polymer nanoparticles exhibit strong fluorescence and have been applied for biological fluorescence imaging in cell culture and in small animals. However, conjugated polymer particles are hydrophobic and often chemically inert materials with diameters ranging from below 50 nm to several microns. As such, conjugated polymer nanoparticles cannot be excreted through the renal system. This drawback has prevented their application for clinical bio-medical imaging. Here, we present fully conjugated polymer nanoparticles based on imidazole units. These nanoparticles can be bio-degraded by activated macrophages. Reactive oxygen species induce scission of the conjugated polymer backbone at the imidazole unit, leading to complete decomposition of the particles into soluble low molecular weight fragments. Furthermore, the nanoparticles can be surface functionalized for directed targeting. The approach opens a wide range of opportunities for conjugated polymer particles in the fields of medical imaging, drug-delivery, and theranostics.Conjugated polymer nanoparticles have been applied for biological fluorescence imaging in cell culture and in small animals, but cannot readily be excreted through the renal system. Here the authors show fully conjugated polymer nanoparticles based on imidazole units that can be bio-degraded by activated macrophages.

  11. Comparative assay of fluorescent antibody test results among twelve European National Reference Laboratories using various anti-rabies conjugates

    DEFF Research Database (Denmark)

    Robardet, E.; Andrieu, S.; Rasmussen, Thomas Bruun

    2013-01-01

    Twelve National Reference Laboratories (NRLs) for rabies have undertaken a comparative assay to assess the comparison of fluorescent antibody test (FAT) results using five coded commercial anti-rabies conjugates (Biorad, Bioveta, Fujirebio, Millipore, and SIFIN conjugates). Homogenized positive...

  12. “Turn on” fluorescence enhancement of Zn octacarboxyphthaloyanine-graphene oxide conjugates by hydrogen peroxide

    Energy Technology Data Exchange (ETDEWEB)

    Shumba, Munyaradzi; Mashazi, Philani; Nyokong, Tebello, E-mail: t.nyokong@ru.ac.za

    2016-02-15

    Zn octacarboxy phthalocyanine-reduced graphene oxide or graphene oxide conjugates were characterized by absorption spectroscopy, transmission electron microscopy, fluorescence spectroscopy, X-ray diffraction, thermo gravimetric analysis and X-ray photon spectroscopy. The presence of reduced graphene oxide or graphene oxide resulted in the quenching (turn on) of Zn octacarboxy phthalocyanine fluorescence which can be explained by photoinduced electron transfer. Zn octacarboxy phthalocyanine-reduced graphene oxide or graphene oxide conjugates “turned on” fluorescence showed a linear response to hydrogen peroxide hence their potential to be used as sensors. The nanoprobe developed showed high selectivity towards hydrogen peroxide in the presence of physiological interferences.

  13. “Turn on” fluorescence enhancement of Zn octacarboxyphthaloyanine-graphene oxide conjugates by hydrogen peroxide

    International Nuclear Information System (INIS)

    Shumba, Munyaradzi; Mashazi, Philani; Nyokong, Tebello

    2016-01-01

    Zn octacarboxy phthalocyanine-reduced graphene oxide or graphene oxide conjugates were characterized by absorption spectroscopy, transmission electron microscopy, fluorescence spectroscopy, X-ray diffraction, thermo gravimetric analysis and X-ray photon spectroscopy. The presence of reduced graphene oxide or graphene oxide resulted in the quenching (turn on) of Zn octacarboxy phthalocyanine fluorescence which can be explained by photoinduced electron transfer. Zn octacarboxy phthalocyanine-reduced graphene oxide or graphene oxide conjugates “turned on” fluorescence showed a linear response to hydrogen peroxide hence their potential to be used as sensors. The nanoprobe developed showed high selectivity towards hydrogen peroxide in the presence of physiological interferences.

  14. Characterization of antibody-chelator conjugates: Determination of chelator content by terbium fluorescence titration

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, K.D.; Schnobrich, K.E.; Johnson, D.K. (Abbott Laboratories, Department 90M, Abbott Park, IL (United States))

    1991-01-01

    Fluorescence titrations were performed by adding varying mole ratios of terbium(III) to antibody conjugates formed by benzyl isothiocyanate derivatives of three different polyaminopolycarboxylate chelators (NTA, EDTA, and DTPA) and the results compared to values for average chelator content obtained by cobalt-57 binding assays. For two different murine monoclonal antibodies, the average chelator content obtained by terbium fluorescence titration correlated closely with that measured by the cobalt-57 binding assay. It is concluded that lanthanide fluorescence titrations provide a useful alternative to radiometal binding assays for the determination of chelator content in protein-chelator conjugates.

  15. Characterization of antibody-chelator conjugates: Determination of chelator content by terbium fluorescence titration

    International Nuclear Information System (INIS)

    Brandt, K.D.; Schnobrich, K.E.; Johnson, D.K.

    1991-01-01

    Fluorescence titrations were performed by adding varying mole ratios of terbium(III) to antibody conjugates formed by benzyl isothiocyanate derivatives of three different polyaminopolycarboxylate chelators (NTA, EDTA, and DTPA) and the results compared to values for average chelator content obtained by cobalt-57 binding assays. For two different murine monoclonal antibodies, the average chelator content obtained by terbium fluorescence titration correlated closely with that measured by the cobalt-57 binding assay. It is concluded that lanthanide fluorescence titrations provide a useful alternative to radiometal binding assays for the determination of chelator content in protein-chelator conjugates

  16. Selective fluorescent detection of aspartic acid and glutamic acid employing dansyl hydrazine dextran conjugate.

    Science.gov (United States)

    Nasomphan, Weerachai; Tangboriboonrat, Pramuan; Tanapongpipat, Sutipa; Smanmoo, Srung

    2014-01-01

    Highly water soluble polymer (DD) was prepared and evaluated for its fluorescence response towards various amino acids. The polymer consists of dansyl hydrazine unit conjugated into dextran template. The conjugation enhances higher water solubility of dansyl hydrazine moiety. Of screened amino acids, DD exhibited selective fluorescence quenching in the presence of aspartic acid (Asp) and glutamic acid (Glu). A plot of fluorescence intensity change of DD against the concentration of corresponding amino acids gave a good linear relationship in the range of 1 × 10(-4) M to 25 × 10(-3) M. This establishes DD as a potential polymeric sensor for selective sensing of Asp and Glu.

  17. A penalized linear and nonlinear combined conjugate gradient method for the reconstruction of fluorescence molecular tomography.

    Science.gov (United States)

    Shang, Shang; Bai, Jing; Song, Xiaolei; Wang, Hongkai; Lau, Jaclyn

    2007-01-01

    Conjugate gradient method is verified to be efficient for nonlinear optimization problems of large-dimension data. In this paper, a penalized linear and nonlinear combined conjugate gradient method for the reconstruction of fluorescence molecular tomography (FMT) is presented. The algorithm combines the linear conjugate gradient method and the nonlinear conjugate gradient method together based on a restart strategy, in order to take advantage of the two kinds of conjugate gradient methods and compensate for the disadvantages. A quadratic penalty method is adopted to gain a nonnegative constraint and reduce the illposedness of the problem. Simulation studies show that the presented algorithm is accurate, stable, and fast. It has a better performance than the conventional conjugate gradient-based reconstruction algorithms. It offers an effective approach to reconstruct fluorochrome information for FMT.

  18. pH-Sensitive polymer assisted self-aggregation of bis(pyrene) in living cells in situ with turn-on fluorescence

    International Nuclear Information System (INIS)

    Duan, Zhongyu; Gao, Yu-Juan; Wang, Yongmei; Hou, Chunyuan; Qiao, Zeng-Ying; Qiao, Shenglin; Wang, Lei; Wang, Hao

    2015-01-01

    Supramolecular self-assemblies with various nanostructures in organic and aqueous solutions have been prepared with desired functions. However, in situ construction of self-assembled superstructures in physiological conditions to achieve expected biological functions remains a challenge. Here, we report a supramolecular system to realize the in situ formation of nanoaggregates in living cells. The bis(pyrene) monomers were dispersed inside of hydrophobic domains of pH-sensitive polymeric micelles and delivered to the lysosomes of cells. In the acidic lysosomes, the bis(pyrene) monomers were released and self-aggregated with turn-on fluorescence. We envision this strategy for in situ construction of supramolecular nanostructures in living cells will pave the way for molecular diagnostics in the future. (paper)

  19. Dual-Color Fluorescence Imaging of Magnetic Nanoparticles in Live Cancer Cells Using Conjugated Polymer Probes

    Science.gov (United States)

    Sun, Minjie; Sun, Bin; Liu, Yun; Shen, Qun-Dong; Jiang, Shaojun

    2016-01-01

    Rapid growth in biological applications of nanomaterials brings about pressing needs for exploring nanomaterial-cell interactions. Cationic blue-emissive and anionic green-emissive conjugated polymers are applied as dual-color fluorescence probes to the surface of negatively charged magnetic nanoparticles through sequentially electrostatic adsorption. These conjugated polymers have large extinction coefficients and high fluorescence quantum yield (82% for PFN and 62% for ThPFS). Thereby, one can visualize trace amount (2.7 μg/mL) of fluorescence-labeled nanoparticles within cancer cells by confocal laser scanning microscopy. Fluorescence labeling by the conjugated polymers is also validated for quantitative determination of the internalized nanoparticles in each individual cell by flow cytometry analysis. Extensive overlap of blue and green fluorescence signals in the cytoplasm indicates that both conjugated polymer probes tightly bind to the surface of the nanoparticles during cellular internalization. The highly charged and fluorescence-labeled nanoparticles non-specifically bind to the cell membranes, followed by cellular uptake through endocytosis. The nanoparticles form aggregates inside endosomes, which yields a punctuated staining pattern. Cellular internalization of the nanoparticles is dependent on the dosage and time. Uptake efficiency can be enhanced three-fold by application of an external magnetic field. The nanoparticles are low cytotoxicity and suitable for simultaneously noninvasive fluorescence and magnetic resonance imaging application. PMID:26931282

  20. Effects of electric and magnetic fields on fluorescence in electron donor and acceptor pairs of pyrene and N-methylphthalimide doped in a polymer film

    Energy Technology Data Exchange (ETDEWEB)

    Yoshizawa, Tomokazu [Research Institute for Electronic Science (RIES), Hokkaido University, N12, W6 Sapporo 060-0812 (Japan); Graduate School of Environmental Earth Science, Hokkaido University, Sapporo 060-0810 (Japan); Mizoguchi, Miwako [Graduate School of Environmental Earth Science, Hokkaido University, Sapporo 060-0810 (Japan); Iimori, Toshifumi [Research Institute for Electronic Science (RIES), Hokkaido University, N12, W6 Sapporo 060-0812 (Japan); Graduate School of Environmental Earth Science, Hokkaido University, Sapporo 060-0810 (Japan); Nakabayashi, Takakazu [Research Institute for Electronic Science (RIES), Hokkaido University, N12, W6 Sapporo 060-0812 (Japan); Graduate School of Environmental Earth Science, Hokkaido University, Sapporo 060-0810 (Japan); Ohta, Nobuhiro [Research Institute for Electronic Science (RIES), Hokkaido University, N12, W6 Sapporo 060-0812 (Japan); Graduate School of Environmental Earth Science, Hokkaido University, Sapporo 060-0810 (Japan)], E-mail: nohta@es.hokudai.ac.jp

    2006-05-09

    External electric-field-induced change in fluorescence spectra as well as in fluorescence decay has been measured for electron donor and acceptor pairs of pyrene (PY) and N-methylphthalimide (NMPI) doped in a polymer film. Field-induced quenching and field-induced shortening of lifetime are observed for fluorescence emitted from the locally excited (LE) state of PY, indicating that intermolecular electron transfer from the excited state of PY to NMPI is enhanced by an electric field in a polymer film. A simulation has been made for the field effect on decay profile of the LE fluorescence of PY. Exciplex fluorescence is also quenched by an electric field because of the field-induced decrease in the initial population of the fluorescent exciplex. Both in LE fluorescence of PY and in exciplex fluorescence, electric-field-induced quenching becomes less efficient in the presence of a magnetic field. The mechanism of the synergy effect of electric and magnetic fields on fluorescence has been discussed.

  1. Effects of electric and magnetic fields on fluorescence in electron donor and acceptor pairs of pyrene and N-methylphthalimide doped in a polymer film

    International Nuclear Information System (INIS)

    Yoshizawa, Tomokazu; Mizoguchi, Miwako; Iimori, Toshifumi; Nakabayashi, Takakazu; Ohta, Nobuhiro

    2006-01-01

    External electric-field-induced change in fluorescence spectra as well as in fluorescence decay has been measured for electron donor and acceptor pairs of pyrene (PY) and N-methylphthalimide (NMPI) doped in a polymer film. Field-induced quenching and field-induced shortening of lifetime are observed for fluorescence emitted from the locally excited (LE) state of PY, indicating that intermolecular electron transfer from the excited state of PY to NMPI is enhanced by an electric field in a polymer film. A simulation has been made for the field effect on decay profile of the LE fluorescence of PY. Exciplex fluorescence is also quenched by an electric field because of the field-induced decrease in the initial population of the fluorescent exciplex. Both in LE fluorescence of PY and in exciplex fluorescence, electric-field-induced quenching becomes less efficient in the presence of a magnetic field. The mechanism of the synergy effect of electric and magnetic fields on fluorescence has been discussed

  2. Modulation of benzo[a]pyrene induced neurotoxicity in female mice actively immunized with a B[a]P–diphtheria toxoid conjugate

    International Nuclear Information System (INIS)

    Schellenberger, Mario T.; Grova, Nathalie; Farinelle, Sophie; Willième, Stéphanie; Schroeder, Henri; Muller, Claude P.

    2013-01-01

    Benzo[a]pyrene (B[a]P) is a small molecular weight carcinogen and the prototype of polycyclic aromatic hydrocarbons (PAHs). While these compounds are primarily known for their carcinogenicity, B[a]P and its metabolites are also neurotoxic for mammalian species. To develop a prophylactic immune strategy against detrimental effects of B[a]P, female Balb/c mice immunized with a B[a]P–diphtheria toxoid (B[a]P–DT) conjugate vaccine were sub-acutely exposed to 2 mg/kg B[a]P and behavioral performances were monitored in tests related to learning and memory, anxiety and motor coordination. mRNA expression of the NMDA receptor (NR1, 2A and 2B subunits) involved in the above behavioral functions was measured in 5 brain regions. B[a]P induced NMDA1 expression in three (hippocampus, amygdala and cerebellum) of five brain regions investigated, and modulated NMDA2 in two of the five brain regions (frontal cortex and cerebellum). Each one of these B[a]P-effects was reversed in mice that were immunized against this PAH, with measurable consequences on behavior such as anxiety, short term learning and memory. Thus active immunization against B[a]P with a B[a]P–DT conjugate vaccine had a protective effect and attenuated the pharmacological and neurotoxic effects even of high concentrations of B[a]P. - Highlights: • B[a]P-antibodies attenuated B[a]P induced NMDA expression in several brain regions. • B[a]P had measurable consequences on anxiety, short term learning and memory. • B[a]P immunization attenuated the pharmacological and neurotoxic effects of B[a]P. • Vaccination may also provide some protection against chemical carcinogenesis

  3. Modulation of benzo[a]pyrene induced neurotoxicity in female mice actively immunized with a B[a]P–diphtheria toxoid conjugate

    Energy Technology Data Exchange (ETDEWEB)

    Schellenberger, Mario T.; Grova, Nathalie; Farinelle, Sophie; Willième, Stéphanie [Institute of Immunology, Centre de Recherche Public de la Santé/Laboratoire National de Santé, 20A rue Auguste Lumière, L-1950 Luxembourg, Grand-Duchy of Luxembourg (Luxembourg); Schroeder, Henri [University of Nancy, URAFPA, INRA UC340, F-54500 Vandoeuvre-lès-Nancy (France); Muller, Claude P., E-mail: claude.muller@crp-sante.lu [Institute of Immunology, Centre de Recherche Public de la Santé/Laboratoire National de Santé, 20A rue Auguste Lumière, L-1950 Luxembourg, Grand-Duchy of Luxembourg (Luxembourg)

    2013-09-01

    Benzo[a]pyrene (B[a]P) is a small molecular weight carcinogen and the prototype of polycyclic aromatic hydrocarbons (PAHs). While these compounds are primarily known for their carcinogenicity, B[a]P and its metabolites are also neurotoxic for mammalian species. To develop a prophylactic immune strategy against detrimental effects of B[a]P, female Balb/c mice immunized with a B[a]P–diphtheria toxoid (B[a]P–DT) conjugate vaccine were sub-acutely exposed to 2 mg/kg B[a]P and behavioral performances were monitored in tests related to learning and memory, anxiety and motor coordination. mRNA expression of the NMDA receptor (NR1, 2A and 2B subunits) involved in the above behavioral functions was measured in 5 brain regions. B[a]P induced NMDA1 expression in three (hippocampus, amygdala and cerebellum) of five brain regions investigated, and modulated NMDA2 in two of the five brain regions (frontal cortex and cerebellum). Each one of these B[a]P-effects was reversed in mice that were immunized against this PAH, with measurable consequences on behavior such as anxiety, short term learning and memory. Thus active immunization against B[a]P with a B[a]P–DT conjugate vaccine had a protective effect and attenuated the pharmacological and neurotoxic effects even of high concentrations of B[a]P. - Highlights: • B[a]P-antibodies attenuated B[a]P induced NMDA expression in several brain regions. • B[a]P had measurable consequences on anxiety, short term learning and memory. • B[a]P immunization attenuated the pharmacological and neurotoxic effects of B[a]P. • Vaccination may also provide some protection against chemical carcinogenesis.

  4. Modulation of Benzo[a]pyrene induced immunotoxicity in mice actively immunized with a B[a]P-diphtheria toxoid conjugate

    International Nuclear Information System (INIS)

    Schellenberger, Mario T.; Grova, Nathalie; Willieme, Stephanie; Farinelle, Sophie; Prodhomme, Emmanuel J.F.; Muller, Claude P.

    2009-01-01

    Benzo[a]pyrene (B[a]P) is a small molecular weight carcinogen and the prototype of polycyclic aromatic hydrocarbons (PAHs). While these compounds are primarily known for their carcinogenicity, B[a]P and its metabolites are also toxic for mammalian immune cells. To develop a prophylactic immune strategy against detrimental effects of B[a]P, we have immunized mice with a B[a]P-diphtheria toxoid conjugate vaccine. We showed that high levels of antibodies against B[a]P and its metabolites modulate the redistribution of these PAHs in the blood. After immunization, increased levels of B[a]P and its metabolites were recovered in the blood. B[a]P significantly suppressed the proliferative response of both T and B cells after a sub-acute administration, an effect that was completely reversed by vaccination. In immunized mice also the immunotoxic effect of B[a]P on IFN-γ, IL-12, TNF-α production and the reduced B cell activation was restored. Finally, our results showed that specific antibodies inhibited the induction of Cyp1a1 by B[a]P in lymphocytes and Cyp1b1 in the liver, enzymes that are known to convert the procarcinogen B[a]P to the ultimate DNA-adduct forming metabolite, a major risk factor of chemical carcinogenesis. Thus, we demonstrate that vaccination with a B[a]P conjugate vaccine based on a carrier protein used in licensed human vaccines reduces immunotoxicity and possibly other detrimental effects associated with B[a]P.

  5. Spectroscopic and TD-DFT studies on the dual mode fluorescent chemosensors based on pyrene thiosemicarbazones, and its application as molecular-scale logic devices

    Energy Technology Data Exchange (ETDEWEB)

    Basheer, Sabeel M. [Department of Chemistry, National Institute of Technology, Tiruchirappalli 620 015 (India); Willis, Anthony C. [Research School of Chemistry, The Australian National University, Canberra, ACT 2601 (Australia); Sreekanth, Anandaram, E-mail: sreekanth@nitt.edu [Department of Chemistry, National Institute of Technology, Tiruchirappalli 620 015 (India)

    2017-03-15

    Two newly synthesised pyrene based molecules are hereby reported as molecular switches. The absorption and emission response for receptors with and without F{sup −}, CN{sup −} and Cu{sup 2+} ions can mimic multiple logic gate such as AND, NOR, XNOR, OR, XOR, INHIBITION and TRANSFER gates. The fluorescence reversibility was checked with the alternative addition of fluoride and calcium ions, which can be explained by the “Read-Erase-Read-Write” logic loop. The calculated binding constant value show PyBTSC is better chemosensor than PyCTSC, and the binding affinity is in the order of Cu{sup 2+}Г‹Ж’F{sup -}Г‹Ж’CN{sup −.} The detailed mechanism was investigated using DFT and TD-DFT calculations. The fluorescence quenching behaviour of receptor-F complex can be explained by PET mechanism along with ESPT process. The proton attached to the nitrogen which is adjacent to pyrene moiety is first make the hydrogen bond with fluoride ion at the excited state, which has confirmed by natural bond orbital (NBO) and potential energy surface (PES) analysis. - Graphical abstract: The newly synthesised thiocarbazone derivates used as an effective and selective colourimetric and “turn on” fluorescence sensor for copper ion and ‘turn off’ for fluoride and cyanide anion. The presence and absence of ions were considered as input signals and the corresponding absorption and emission responses were consired as output. The proton transfer from the nitrogen adjacent to pyrene moiety, and which takes place at the excited state (ESPT).

  6. A sulfhydryl-reactive ruthenium (II complex and its conjugation to protein G as a universal reagent for fluorescent immunoassays.

    Directory of Open Access Journals (Sweden)

    Jing-Tang Lin

    Full Text Available To develop a fluorescent ruthenium complex for biosensing, we synthesized a novel sulfhydryl-reactive compound, 4-bromophenanthroline bis-2,2'-dipyridine Ruthenium bis (hexafluorophosphate. The synthesized Ru(II complex was crosslinked with thiol-modified protein G to form a universal reagent for fluorescent immunoassays. The resulting Ru(II-protein G conjugates were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE. The emission peak wavelength of the Ru(II-protein G conjugate was 602 nm at the excitation of 452 nm which is similar to the spectra of the Ru(II complex, indicating that Ru(II-protein G conjugates still remain the same fluorescence after conjugation. To test the usefulness of the conjugate for biosensing, immunoglobulin G (IgG binding assay was conducted. The result showed that Ru(II-protein G conjugates were capable of binding IgG and the more cross-linkers to modify protein G, the higher conjugation efficiency. To demonstrate the feasibility of Ru(II-protein G conjugates for fluorescent immunoassays, the detection of recombinant histidine-tagged protein using the conjugates and anti-histidine antibody was developed. The results showed that the histidine-tagged protein was successfully detected with dose-response, indicating that Ru(II-protein G conjugate is a useful universal fluorescent reagent for quantitative immunoassays.

  7. Fluorescence and confocal imaging of mammalian cells using conjugated oligoelectrolytes with phenylenevinylene core

    Energy Technology Data Exchange (ETDEWEB)

    Milczarek, Justyna; Pawlowska, Roza; Zurawinski, Remigiusz; Lukasik, Beata; Garner, Logan E.; Chworos, Arkadiusz

    2017-05-01

    Over the last few years, considerable efforts are taken, in order to find a molecular fluorescent probe fulfilling their applicability requirements. Due to a good optical properties and affinity to biological structures conjugated oligoelectrolytes (COEs) can be considered as a promising dyes for application in fluorescence-based bioimaging. In this work, we synthetized COEs with phenylenevinylene core (PV-COEs) and applied as fluorescent membranous-specific probes. Cytotoxicity effects of each COE were probed on cancerous and non-cancerous cell types and little to no toxicity effects were observed at the high range of concentrations. The intensity of cell fluorescence following the COE staining was determined by the photoluminescence analysis and fluorescence activated cell sorting method (FACS). Intercalation of tested COEs into mammalian cell membranes was revealed by fluorescent and confocal microscopy colocalization with commercial dyes specific for cellular structures including mitochondria, Golgi apparatus and endoplasmic reticulum. The phenylenevinylene conjugated oligoelectrolytes have been found to be suitable for fluorescent bioimaging of mammalian cells and membrane-rich organelles. Due to their water solubility coupled with spontaneous intercalation into cells, favorable photophysical features, ease of cell staining, low cytotoxicity and selectivity for membranous structures, PV-COEs can be applied as markers for fluorescence imaging of a variety of cell types.

  8. Characterizing the glymphatic influx by utilizing intracisternal infusion of fluorescently conjugated cadaverine.

    Science.gov (United States)

    Zhang, Cui; Lin, Jun; Wei, Fang; Song, Jian; Chen, Wenyue; Shan, Lidong; Xue, Rong; Wang, Guoqing; Tao, Jin; Zhang, Guoxing; Xu, Guang-Yin; Wang, Linhui

    2018-05-15

    Accumulating evidence supports that cerebrospinal fluid (CSF) in the subarachnoid space (SAS) could reenter the brain parenchyma via the glymphatic influx. The present study was designed to characterize the detailed pathway of subarachnoid CSF influx by using a novel CSF tracer. Fluorescently conjugated cadaverine (A488-ca), for the first time, was employed to investigate CSF movement in the brain. Following intracisternal infusion of CSF tracers, mice brain was sliced and prepared for fluorescence imaging. Some brain sections were immunostained in order to observe tracer distribution and cellular uptake. A488-ca moved into the brain parenchyma rapidly, and the influx was time and region dependent. A488-ca entered the mice brain more readily and spread more widely than another commonly used CSF tracer-fluorescently conjugated ovalbumin (OA-45). Furthermore, A488-ca could enter the brain parenchyma either along the paravascular space or across the pial surface. Suppression of glymphatic transport by administration with acetazolamide strikingly reduced the influx of A488-ca. More importantly, relative to OA-45 largely remained in the extracellular space, A488-ca exhibited obvious cellular uptake by astrocytes surrounding the blood vessels and neurons in the cerebral cortex. Subarachnoid CSF could flow into the brain parenchyma via the glymphatic influx, in which the transcellular pathway was faithfully traced by intracisternal infusion with fluorescently conjugated cadaverine. These observations extend our comprehension on the glymphatic influx pathway. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Separation of water-soluble metabolites of benzo[a]pyrene formed by cultured human colon

    DEFF Research Database (Denmark)

    Autrup, Herman

    1979-01-01

    A method has been developed to separate conjugated metabolites of benzo[a]pyrene into three major fractions: sulfate esters, glucuronides and glutathione conjugates. In cultured human colon, formation of sulfate esters and glutathione conjugates is the major conjugation pathway, while formation......-hydroxybenzo[a]pyrene were the major substrates for sulfotransferase in cultured human colon....

  10. Determination of benzo[a]pyrene in edible oils using phase-transfer-catalyst-assisted saponification and supramolecular solvent microextraction coupled to HPLC with fluorescence detection.

    Science.gov (United States)

    Wang, Jin; Liu, Laping; Shi, Ludi; Yi, Tingquan; Wen, Yuxia; Wang, Juanli; Liu, Shuhui

    2017-01-01

    For the analysis of edible oils, saponification is well known as a useful method for eliminating oil matrices. The conventional approach is conducted with alcoholic alkali; it consumes a large volume of organic solvents and impedes the retrieval of analytes by microextraction. In this study, a low-organic-solvent-consuming method has been developed for the analysis of benzo[a]pyrene in edible oils by high-performance liquid chromatography with fluorescence detection. Sample treatment involves aqueous alkaline saponification, assisted by a phase-transfer catalyst, and selective in situ extraction of the analyte with a supramolecular solvent. Comparison of the chromatograms of the oil extracts obtained by different microextraction methods showed that the supramolecular solvent has a better clean-up effect for the unsaponifiable matter from oil matrices. The method offered excellent linearity over a range of 0.03- 5.0 ng mL -1 (r > 0.999). Recovery rates varied from 94 to 102% (RSDs <5.0%). The detection limit and quantification limit were 0.06 and 0.19 μg kg -1 , respectively. The proposed method was applied for the analysis of 52 edible oils collected online in China; the analyte contents of 23 tested oil samples exceeded the maximum limit of 2 μg kg -1 for benzo[a]pyrene set by the Commission Regulation of the European Union. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. pH-responsive fluorescence chemical sensor constituted by conjugated polymers containing pyridine rings.

    Science.gov (United States)

    Adachi, Naoya; Kaneko, Yuki; Sekiguchi, Kazuki; Sugiyama, Hiroki; Sugeno, Masafumi

    2015-12-01

    Poly(p-pyridinium phenylene ethynylene)s (PPyPE) functionalized with alternating donor-acceptor repeat units were synthesized by a Pd-catalyzed Sonogashira coupling reaction between diethynyl monomer and di-iodopyridine for use as a pH-responsive fluorescence chemical sensor. The synthesized PPyPE, containing pyridine units, was characterized by FT-IR, (1)H and (13)C NMR, UV-visible and fluorescence spectroscopies. We investigated the relationship between changes of optical properties and protonation/deprotonation of PPyPE containing pyridine units in solution. Addition of HCl decreased and red-shifted the fluorescence intensity of the conjugated polymers that contained pyridine rings; fluorescence intensity of the polymers increased upon addition of NaOH solution. The synthesized PPyPE was found to be an effective and reusable chemical sensor for pH sensing. Copyright © 2015 John Wiley & Sons, Ltd.

  12. Liquid chromatographic determination of microcystins in water samples following pre-column excimer fluorescence derivatization with 4-(1-pyrene)butanoic acid hydrazide.

    Science.gov (United States)

    Hayama, Tadashi; Katoh, Kenji; Aoki, Takayoshi; Itoyama, Miki; Todoroki, Kenichiro; Yoshida, Hideyuki; Yamaguchi, Masatoshi; Nohta, Hitoshi

    2012-11-28

    A method to measure the concentrations of microcystins (MCs) in water samples has been developed by incorporating pre-column fluorescence derivatization and liquid chromatography (LC). A solid-phase extraction for pretreatment was used to extract the MCs in water samples. The MCs were derivatized with excimer-forming 4-(1-pyrene)butanoic acid hydrazide (PBH). The MCs could then be detected by fluorescence after separation with a pentafluorophenyl (PFP)-modified superficially porous (core shell) particle LC column. The derivatization reactions of MCs with PBH proceeded easily in the presence of 4,6-dimethoxy-1,3,5-triazin-2-yl-4-methylmorpholinium (DMT-MM) as a condensation reagent, and the resulting derivatives could be easily separated on the PFP column. The derivatives were selectively detected at excimer fluorescence wavelengths (440-540 nm). The instrument detection limit and the instrument quantification limit of the MCs standards were 0.4-1.2 μg L(-1) and 1.4-3.9 μg L(-1), respectively. The method was validated at 0.1 and 1.0 μg L(-1) levels in tap and pond water samples, and the recovery of MCs was between 67 and 101% with a relative standard deviation of 11%. The proposed method can be used to quantify trace amounts of MCs in water samples. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. A novel fluorescent retrograde neural tracer: cholera toxin B conjugated carbon dots

    Science.gov (United States)

    Zhou, Nan; Hao, Zeyu; Zhao, Xiaohuan; Maharjan, Suraj; Zhu, Shoujun; Song, Yubin; Yang, Bai; Lu, Laijin

    2015-09-01

    The retrograde neuroanatomical tracing method is a key technique to study the complex interconnections of the nervous system. Traditional tracers have several drawbacks, including time-consuming immunohistochemical or immunofluorescent staining procedures, rapid fluorescence quenching and low fluorescence intensity. Carbon dots (CDs) have been widely used as a fluorescent bio-probe due to their ultrasmall size, excellent optical properties, chemical stability, biocompatibility and low toxicity. Herein, we develop a novel fluorescent neural tracer: cholera toxin B-carbon dot conjugates (CTB-CDs). It can be taken up and retrogradely transported by neurons in the peripheral nervous system of rats. Our results show that CTB-CDs possess high photoluminescence intensity, good optical stability, a long shelf-life and non-toxicity. Tracing with CTB-CDs is a direct and more economical way of performing retrograde labelling experiments. Therefore, CTB-CDs are reliable fluorescent retrograde tracers.The retrograde neuroanatomical tracing method is a key technique to study the complex interconnections of the nervous system. Traditional tracers have several drawbacks, including time-consuming immunohistochemical or immunofluorescent staining procedures, rapid fluorescence quenching and low fluorescence intensity. Carbon dots (CDs) have been widely used as a fluorescent bio-probe due to their ultrasmall size, excellent optical properties, chemical stability, biocompatibility and low toxicity. Herein, we develop a novel fluorescent neural tracer: cholera toxin B-carbon dot conjugates (CTB-CDs). It can be taken up and retrogradely transported by neurons in the peripheral nervous system of rats. Our results show that CTB-CDs possess high photoluminescence intensity, good optical stability, a long shelf-life and non-toxicity. Tracing with CTB-CDs is a direct and more economical way of performing retrograde labelling experiments. Therefore, CTB-CDs are reliable fluorescent retrograde

  14. Luminescent conjugated oligothiophenes for sensitive fluorescent assignment of protein inclusion bodies.

    Science.gov (United States)

    Klingstedt, Therése; Blechschmidt, Cristiane; Nogalska, Anna; Prokop, Stefan; Häggqvist, Bo; Danielsson, Olof; Engel, W King; Askanas, Valerie; Heppner, Frank L; Nilsson, K Peter R

    2013-03-18

    Small hydrophobic ligands identifying intracellular protein deposits are of great interest, as protein inclusion bodies are the pathological hallmark of several degenerative diseases. Here we report that fluorescent amyloid ligands, termed luminescent conjugated oligothiophenes (LCOs), rapidly and with high sensitivity detect protein inclusion bodies in skeletal muscle tissue from patients with sporadic inclusion body myositis (s-IBM). LCOs having a conjugated backbone of at least five thiophene units emitted strong fluorescence upon binding, and showed co-localization with proteins reported to accumulate in s-IBM protein inclusion bodies. Compared with conventional amyloid ligands, LCOs identified a larger fraction of immunopositive inclusion bodies. When the conjugated thiophene backbone was extended with terminal carboxyl groups, the LCO revealed striking spectral differences between distinct protein inclusion bodies. We conclude that 1) LCOs are sensitive, rapid and powerful tools for identifying protein inclusion bodies and 2) LCOs identify a wider range of protein inclusion bodies than conventional amyloid ligands. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Fluorescent Binary Ensemble Based on Pyrene Derivative and Sodium Dodecyl Sulfate Assemblies as a Chemical Tongue for Discriminating Metal Ions and Brand Water.

    Science.gov (United States)

    Zhang, Lijun; Huang, Xinyan; Cao, Yuan; Xin, Yunhong; Ding, Liping

    2017-12-22

    Enormous effort has been put to the detection and recognition of various heavy metal ions due to their involvement in serious environmental pollution and many major diseases. The present work has developed a single fluorescent sensor ensemble that can distinguish and identify a variety of heavy metal ions. A pyrene-based fluorophore (PB) containing a metal ion receptor group was specially designed and synthesized. Anionic surfactant sodium dodecyl sulfate (SDS) assemblies can effectively adjust its fluorescence behavior. The selected binary ensemble based on PB/SDS assemblies can exhibit multiple emission bands and provide wavelength-based cross-reactive responses to a series of metal ions to realize pattern recognition ability. The combination of surfactant assembly modulation and the receptor for metal ions empowers the present sensor ensemble with strong discrimination power, which could well differentiate 13 metal ions, including Cu 2+ , Co 2+ , Ni 2+ , Cr 3+ , Hg 2+ , Fe 3+ , Zn 2+ , Cd 2+ , Al 3+ , Pb 2+ , Ca 2+ , Mg 2+ , and Ba 2+ . Moreover, this single sensing ensemble could be further applied for identifying different brands of drinking water.

  16. Evaluation of Antigen-Conjugated Fluorescent Beads to Identify Antigen-Specific B Cells.

    Science.gov (United States)

    Correa, Isabel; Ilieva, Kristina M; Crescioli, Silvia; Lombardi, Sara; Figini, Mariangela; Cheung, Anthony; Spicer, James F; Tutt, Andrew N J; Nestle, Frank O; Karagiannis, Panagiotis; Lacy, Katie E; Karagiannis, Sophia N

    2018-01-01

    Selection of single antigen-specific B cells to identify their expressed antibodies is of considerable interest for evaluating human immune responses. Here, we present a method to identify single antibody-expressing cells using antigen-conjugated fluorescent beads. To establish this, we selected Folate Receptor alpha (FRα) as a model antigen and a mouse B cell line, expressing both the soluble and the membrane-bound forms of a human/mouse chimeric antibody (MOv18 IgG1) specific for FRα, as test antibody-expressing cells. Beads were conjugated to FRα using streptavidin/avidin-biotin bridges and used to select single cells expressing the membrane-bound form of anti-FRα. Bead-bound cells were single cell-sorted and processed for single cell RNA retrotranscription and PCR to isolate antibody heavy and light chain variable regions. Variable regions were then cloned and expressed as human IgG1/k antibodies. Like the original clone, engineered antibodies from single cells recognized native FRα. To evaluate whether antigen-coated beads could identify specific antibody-expressing cells in mixed immune cell populations, human peripheral blood mononuclear cells (PBMCs) were spiked with test antibody-expressing cells. Antigen-specific cells could comprise up to 75% of cells selected with antigen-conjugated beads when the frequency of the antigen-positive cells was 1:100 or higher. In PBMC pools, beads conjugated to recombinant antigens FRα and HER2 bound antigen-specific anti-FRα MOv18 and anti-HER2 Trastuzumab antibody-expressing cells, respectively. From melanoma patient-derived B cells selected with melanoma cell line-derived protein-coated fluorescent beads, we generated a monoclonal antibody that recognized melanoma antigen-coated beads. This approach may be further developed to facilitate analysis of B cells and their antibody profiles at the single cell level and to help unravel humoral immune repertoires.

  17. Evaluation of Antigen-Conjugated Fluorescent Beads to Identify Antigen-Specific B Cells

    Directory of Open Access Journals (Sweden)

    Isabel Correa

    2018-03-01

    Full Text Available Selection of single antigen-specific B cells to identify their expressed antibodies is of considerable interest for evaluating human immune responses. Here, we present a method to identify single antibody-expressing cells using antigen-conjugated fluorescent beads. To establish this, we selected Folate Receptor alpha (FRα as a model antigen and a mouse B cell line, expressing both the soluble and the membrane-bound forms of a human/mouse chimeric antibody (MOv18 IgG1 specific for FRα, as test antibody-expressing cells. Beads were conjugated to FRα using streptavidin/avidin-biotin bridges and used to select single cells expressing the membrane-bound form of anti-FRα. Bead-bound cells were single cell-sorted and processed for single cell RNA retrotranscription and PCR to isolate antibody heavy and light chain variable regions. Variable regions were then cloned and expressed as human IgG1/k antibodies. Like the original clone, engineered antibodies from single cells recognized native FRα. To evaluate whether antigen-coated beads could identify specific antibody-expressing cells in mixed immune cell populations, human peripheral blood mononuclear cells (PBMCs were spiked with test antibody-expressing cells. Antigen-specific cells could comprise up to 75% of cells selected with antigen-conjugated beads when the frequency of the antigen-positive cells was 1:100 or higher. In PBMC pools, beads conjugated to recombinant antigens FRα and HER2 bound antigen-specific anti-FRα MOv18 and anti-HER2 Trastuzumab antibody-expressing cells, respectively. From melanoma patient-derived B cells selected with melanoma cell line-derived protein-coated fluorescent beads, we generated a monoclonal antibody that recognized melanoma antigen-coated beads. This approach may be further developed to facilitate analysis of B cells and their antibody profiles at the single cell level and to help unravel humoral immune repertoires.

  18. Evaluation of Antigen-Conjugated Fluorescent Beads to Identify Antigen-Specific B Cells

    Science.gov (United States)

    Correa, Isabel; Ilieva, Kristina M.; Crescioli, Silvia; Lombardi, Sara; Figini, Mariangela; Cheung, Anthony; Spicer, James F.; Tutt, Andrew N. J.; Nestle, Frank O.; Karagiannis, Panagiotis; Lacy, Katie E.; Karagiannis, Sophia N.

    2018-01-01

    Selection of single antigen-specific B cells to identify their expressed antibodies is of considerable interest for evaluating human immune responses. Here, we present a method to identify single antibody-expressing cells using antigen-conjugated fluorescent beads. To establish this, we selected Folate Receptor alpha (FRα) as a model antigen and a mouse B cell line, expressing both the soluble and the membrane-bound forms of a human/mouse chimeric antibody (MOv18 IgG1) specific for FRα, as test antibody-expressing cells. Beads were conjugated to FRα using streptavidin/avidin-biotin bridges and used to select single cells expressing the membrane-bound form of anti-FRα. Bead-bound cells were single cell-sorted and processed for single cell RNA retrotranscription and PCR to isolate antibody heavy and light chain variable regions. Variable regions were then cloned and expressed as human IgG1/k antibodies. Like the original clone, engineered antibodies from single cells recognized native FRα. To evaluate whether antigen-coated beads could identify specific antibody-expressing cells in mixed immune cell populations, human peripheral blood mononuclear cells (PBMCs) were spiked with test antibody-expressing cells. Antigen-specific cells could comprise up to 75% of cells selected with antigen-conjugated beads when the frequency of the antigen-positive cells was 1:100 or higher. In PBMC pools, beads conjugated to recombinant antigens FRα and HER2 bound antigen-specific anti-FRα MOv18 and anti-HER2 Trastuzumab antibody-expressing cells, respectively. From melanoma patient-derived B cells selected with melanoma cell line-derived protein-coated fluorescent beads, we generated a monoclonal antibody that recognized melanoma antigen-coated beads. This approach may be further developed to facilitate analysis of B cells and their antibody profiles at the single cell level and to help unravel humoral immune repertoires. PMID:29628923

  19. A fluorescent sensor based on dansyl-diethylenetriamine-thiourea conjugate: a through theoretical investigation

    International Nuclear Information System (INIS)

    Nguyen Khoa Hien; Nguyen Thi Ai Nhung; Duong Tuan Quang; Ho Quoc Dai; Nguyen Tien Trung

    2015-01-01

    A new dansyl-diethylenetriamine-thiourea conjugate (DT) for detection of Hg 2+ ions in aqueous solution has been theoretically designed and compared to our previously published results. The synthetic path, the optimized geometric structure and the characteristics of the DT were found by the theoretical calculations at the B3LYP/LanL2DZ level. Accordingly, the DT can react with Hg 2+ ion to form a product with quenched fluorescence. It is remarkable that the experimental results are in an excellent agreement with the theoretically evaluated data. (author)

  20. Reconstruction for limited-projection fluorescence molecular tomography based on projected restarted conjugate gradient normal residual.

    Science.gov (United States)

    Cao, Xu; Zhang, Bin; Liu, Fei; Wang, Xin; Bai, Jing

    2011-12-01

    Limited-projection fluorescence molecular tomography (FMT) can greatly reduce the acquisition time, which is suitable for resolving fast biology processes in vivo but suffers from severe ill-posedness because of the reconstruction using only limited projections. To overcome the severe ill-posedness, we report a reconstruction method based on the projected restarted conjugate gradient normal residual. The reconstruction results of two phantom experiments demonstrate that the proposed method is feasible for limited-projection FMT. © 2011 Optical Society of America

  1. Pyrene based D-π-A architectures: synthesis, density functional theory, photophysics and electron transfer dynamics.

    Science.gov (United States)

    Kathiravan, Arunkumar; Srinivasan, Venkatesan; Khamrang, Themmila; Velusamy, Marappan; Jaccob, Madhavan; Pavithra, Nagaraj; Anandan, Sambandam; Velappan, Kandavelu

    2017-01-25

    Pyrene derivatives show immense potential as sensitizers for dye-sensitized solar cells (DSCs). Therefore, this work focuses on the impact of π-spacers on the photophysical, electrochemical and photovoltaic properties of pyrene based D-π-A dyes, since the insertion of π-spacers is one of the doable strategies to improve the light harvesting properties of the dye. In this respect, three new pyrene based D-π-A dyes have been synthesized and characterized by 1 H, 13 C NMR, and elemental analyses and EI-MS spectrometry. The selected π-spacers are benzene, thiophene and furan. Compared with a benzene spacer, the introduction of a heterocyclic ring spacer reduces the band gap of the dye and brings about the broadening of the absorption spectra to the longer wavelength region through intramolecular charge-transfer (ICT). Combined experimental and theoretical studies were performed to investigate the ICT process involved in the pyrene derivatives. The profound solvatochromism with increased nonradiative rate constants (k nr ) has been construed in terms of ICT from the pyrene core to rhodanine-3-acetic acid via conjugated π-spacers. Electrochemical data also reveal that the HOMO and LUMO energy levels are fine-tuned by incorporating different π-spacers between pyrene and rhodanine-3-acetic acid. On the basis of the optimized DSC test conditions, the best performance was found for PBRA, in which a benzene group is the conjugated π-spacer. The divergence in the photovoltaic behaviors of these dyes was further explicated by femtosecond fluorescence and electrochemical impedance spectroscopy.

  2. Fluorescence resonance energy transfer between conjugated molecules infiltrated in three-dimensional opal photonic crystals

    International Nuclear Information System (INIS)

    Zou, Lu; Sui, Ning; Wang, Ying-Hui; Qian, Cheng; Ma, Yu-Guang; Zhang, Han-Zhuang

    2015-01-01

    Fluorescence resonance energy transfer (FRET) from Coumarin 6 (C-6) to Sulforhodamine B (S-B) infiltrated into opal PMMA (poly-methyl-methacrylate) photonic crystals (PCs) has been studied in detail. The intrinsic mesh micro-porous structure of opal PCs could increase the luminescent efficiency through inhibiting the intermolecular interaction. Meanwhile, its structure of periodically varying refractive indices could also modify the FRET through affecting the luminescence characteristics of energy donor or energy acceptor. The results demonstrate that the FRET efficiency between conjugated dyes was easily modified by opal PCs. - Highlights: • We investigate the fluorescence resonance energy transfer between two kinds of dyes. • These two kinds of dyes are infiltrated in PMMA opal photonic crystals. • The structure of opal PCs could improve the luminescent characteristics. • The structure of opal PCs could improve the energy transfer characteristics

  3. Efficient L1 regularization-based reconstruction for fluorescent molecular tomography using restarted nonlinear conjugate gradient.

    Science.gov (United States)

    Shi, Junwei; Zhang, Bin; Liu, Fei; Luo, Jianwen; Bai, Jing

    2013-09-15

    For the ill-posed fluorescent molecular tomography (FMT) inverse problem, the L1 regularization can protect the high-frequency information like edges while effectively reduce the image noise. However, the state-of-the-art L1 regularization-based algorithms for FMT reconstruction are expensive in memory, especially for large-scale problems. An efficient L1 regularization-based reconstruction algorithm based on nonlinear conjugate gradient with restarted strategy is proposed to increase the computational speed with low memory consumption. The reconstruction results from phantom experiments demonstrate that the proposed algorithm can obtain high spatial resolution and high signal-to-noise ratio, as well as high localization accuracy for fluorescence targets.

  4. HAI-178 antibody-conjugated fluorescent magnetic nanoparticles for targeted imaging and simultaneous therapy of gastric cancer

    Science.gov (United States)

    Wang, Can; Bao, Chenchen; Liang, Shujing; Zhang, Lingxia; Fu, Hualin; Wang, Yutian; Wang, Kan; Li, Chao; Deng, Min; Liao, Qiande; Ni, Jian; Cui, Daxiang

    2014-05-01

    The successful development of safe and highly effective nanoprobes for targeted imaging and simultaneous therapy of in vivo gastric cancer is a great challenge. Herein we reported for the first time that anti-α-subunit of ATP synthase antibody, HAI-178 monoclonal antibody-conjugated fluorescent magnetic nanoparticles, was successfully used for targeted imaging and simultaneous therapy of in vivo gastric cancer. A total of 172 specimens of gastric cancer tissues were collected, and the expression of α-subunit of ATP synthase in gastric cancer tissues was investigated by immunohistochemistry method. Fluorescent magnetic nanoparticles were prepared and conjugated with HAI-178 monoclonal antibody, and the resultant HAI-178 antibody-conjugated fluorescent magnetic nanoparticles (HAI-178-FMNPs) were co-incubated with gastric cancer MGC803 cells and gastric mucous GES-1 cells. Gastric cancer-bearing nude mice models were established, were injected with prepared HAI-178-FMNPs via tail vein, and were imaged by magnetic resonance imaging and small animal fluorescent imaging system. The results showed that the α-subunit of ATP synthase exhibited high expression in 94.7% of the gastric cancer tissues. The prepared HAI-178-FMNPs could target actively MGC803 cells, realized fluorescent imaging and magnetic resonance imaging of in vivo gastric cancer, and actively inhibited growth of gastric cancer cells. In conclusion, HAI-178 antibody-conjugated fluorescent magnetic nanoparticles have a great potential in applications such as targeted imaging and simultaneous therapy of in vivo early gastric cancer cells in the near future.

  5. Unlocked Nucleic Acids with a Pyrene-Modified Uracil: Synthesis, Hybridization Studies, Fluorescent Properties and i-Motif Stability

    Czech Academy of Sciences Publication Activity Database

    Perlíková, Pavla; Karlsen, K. K.; Pedersen, E. B.; Wengel, J.

    2014-01-01

    Roč. 15, č. 1 (2014), s. 146-156 ISSN 1439-4227 Grant - others:European Research Council(XE) FP7-268776 Institutional support: RVO:61388963 Keywords : fluorescence * i-motifs * nucleic acid hybridization * oligonucleotides * unlocked nucleic acids Subject RIV: CE - Biochemistry Impact factor: 3.088, year: 2014

  6. Aptamer conjugated paclitaxel and magnetic fluid loaded fluorescently tagged PLGA nanoparticles for targeted cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Aravind, Athulya; Nair, Remya; Raveendran, Sreejith; Veeranarayanan, Srivani; Nagaoka, Yutaka; Fukuda, Takahiro; Hasumura, Takahashi; Morimoto, Hisao; Yoshida, Yasuhiko; Maekawa, Toru; Sakthi Kumar, D., E-mail: sakthi@toyo.jp

    2013-10-15

    Controlled and targeted drug delivery is an essential criterion in cancer therapy to reduce the side effects caused by non-specific drug release and toxicity. Targeted chemotherapy, sustained drug release and optical imaging have been achieved using a multifunctional nanocarrier constructed from poly (D, L-lactide-co-glycolide) nanoparticles (PLGA NPs), an anticancer drug paclitaxel (PTX), a fluorescent dye Nile red (NR), magnetic fluid (MF) and aptamers (Apt, AS1411, anti-nucleolin aptamer). The magnetic fluid and paclitaxel loaded fluorescently labeled PLGA NPs (MF-PTX-NR-PLGA NPs) were synthesized by a single-emulsion technique/solvent evaporation method using a chemical cross linker bis (sulfosuccinimidyl) suberate (BS3) to enable binding of aptamer on to the surface of the nanoparticles. Targeting aptamers were then introduced to the particles through the reaction with the cross linker to target the nucleolin receptors over expressed on the cancer cell surface. Specific binding and uptake of the aptamer conjugated magnetic fluid loaded fluorescently tagged PLGA NPs (Apt-MF-NR-PLGA NPs) to the target cancer cells induced by aptamers was observed using confocal microscopy. Cytotoxicity assay conducted in two cell lines (L929 and MCF-7) confirmed that targeted MCF-7 cancer cells were killed while control cells were unharmed. In addition, aptamer mediated delivery resulting in enhanced binding and uptake to the target cancer cells exhibited increased therapeutic effect of the drug. Moreover, these aptamer conjugated magnetic polymer vehicles apart from actively transporting drugs into specifically targeted tumor regions can also be used to induce hyperthermia or for facilitating magnetic guiding of particles to the tumor regions. - Highlights: • Aptamer escorted, theranostic biodegradable PLGA carriers were developed. • Can target cancer cells, control drug release, image and magnetically guide. • Highly specific to the targeted cancer cells thus delivering

  7. Distinct Interfacial Fluorescence in Oil-in-Water Emulsions via Exciton Migration of Conjugated Polymers.

    Science.gov (United States)

    Koo, Byungjin; Swager, Timothy M

    2017-09-01

    Commercial dyes are extensively utilized to stain specific phases for the visualization applications in emulsions and bioimaging. In general, dyes emit only one specific fluorescence signal and thus, in order to stain various phases and/or interfaces, one needs to incorporate multiple dyes and carefully consider their compatibility to avoid undesirable interactions with each other and with the components in the system. Herein, surfactant-type, perylene-endcapped fluorescent conjugated polymers that exhibit two different emissions are reported, which are cyan in water and red at oil-water interfaces. The interfacially distinct red emission results from enhanced exciton migration from the higher-bandgap polymer backbone to the lower-bandgap perylene endgroup. The confocal microscopy images exhibit the localized red emission exclusively from the circumference of oil droplets. This exciton migration and dual fluorescence of the polymers in different physical environments can provide a new concept of visualization methods in many amphiphilic colloidal systems and bioimaging. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Structural Modifications and Photophysical Studies of Fluorescent Conjugated Polymers for Solid State Sensor Development

    Science.gov (United States)

    Chen, Anting

    Fluorescent conjugated polymers (FCPs) represent an exciting area of research in chemosensors and biosensors. Previously, the polymer tmeda-PPETE, N,N,N'-trimethylethylenediamino (tmeda) receptors on a poly[2,5-thiophenediyl-1,2-ethynediyl-1,4-phenylenediyl-1,2-ethynediyl] (PPETE) backbone, showed significant quenching when copper(II) was added. Tmeda-PPETE polymer preloaded with copper(II) was found to be a fluorescent "turn-on" sensor for iron cations. Additional investigation of this metallopolymer revealed a selective sensory system toward carbonate and phosphorus anions through a competitive binding of copper(II) between the polymer tmeda-PPETE and the anions. Fluorescent turn-on response under systematically varied pH was affected by the equilibrium shift of the ionization of polyprotic ions. A sterically hindered pentiptycene group was introduced to the PPETE polymer backbone aiming to reduce aggregation and self-quenching in the solid state. A new FCP, tmeda-PPpETE (poly[(pentiptycene ethynylene)-alt-(thienylene ethynylene)] with tmeda receptors, has been designed and synthesized via Sonogashira cross-coupling reaction. Absorption and emission spectra of tmeda-PPpETE showed blue shifting from tmeda-PPETE, suggesting increased rigidity of polymer backbone. Tmeda-PPpETE showed a high selectivity towards copper(II) with improved sensitivity compared to tmeda-PPETE. The fluorescent quenching response is over 120-fold at emission maximum, and the detection limit is 1.04 ppb, significantly lower than the EPA action level of 1.3 ppm for copper(II). A small turn-off fluorescent response of tmeda-PPpETE was also observed upon addition of iron cations. To further investigate the interaction between pentiptycene containing polymers and iron cations, tmpda-PPpETE containing N,N,N'-trimethylpropylenediamino (tmpda) receptors was designed and synthesized. The absorption and emission spectra for tmpda-PPpETE were analogous to those of tmeda-PPpETE, with a higher quantum

  9. Spectral characterization of the fluorescent components present in humic substances, fulvic acid and humic acid mixed with pure benzo(a)pyrene solution

    Science.gov (United States)

    El Fallah, Rawa; Rouillon, Régis; Vouvé, Florence

    2018-06-01

    The fate of benzo(a)pyrene (BaP), a ubiquitous contaminant reported to be persistent in the environment, is largely controlled by its interactions with the soil organic matter. In the present study, the spectral characteristics of fluorophores present in the physical fractions of the soil organic matter were investigated in the presence of pure BaP solution. After extraction of humic substances (HSs), and their fractionation into fluvic acid (FA) and humic acid (HA), two fluorescent compounds (C1 and C2) were identified and characterized in each physical soil fraction, by means of fluorescence excitation-emission matrices (FEEMs) and Parallel Factor Analysis (PARAFAC). Then, to each type of fraction having similar DOC content, was added an increasing volume of pure BaP solution in attempt to assess the behavior of BaP with the fluorophores present in each one. The application of FEEMs-PARAFAC method validated a three-component model that consisted of the two resulted fluorophores from HSs, FA and HA (C1 and C2) and a BaP-like fluorophore (C3). Spectral modifications were noted for components C2HSs (C2 in humic substances fraction) (λex/λem: 420/490-520 nm), C2FA (C2 in fulvic acid fraction) (λex/λem: 400/487(517) nm) and C1HA (C1 in humic acid fraction) (λex/λem: 350/452(520) nm). We explored the impact of increasing the volume of the added pure BaP solution on the scores of the fluorophores present in the soil fractions. It was found that the scores of C2HSs, C2FA, and C1HA increased when the volume of the added pure BaP solution increased. Superposition of the excitation spectra of these fluorophores with the emission spectrum of BaP showed significant overlaps that might explain the observed interactions between BaP and the fluorescent compounds present in SOM physical fractions.

  10. Design of near-infrared fluorescent bioactive conjugated functional iron oxide nanoparticles for optical detection of colon cancer

    Directory of Open Access Journals (Sweden)

    Corem-Salkmon E

    2012-10-01

    Full Text Available Enav Corem-Salkmon, Benny Perlstein, Shlomo MargelThe Institute of Nanotechnology and Advanced Materials, Department of Chemistry, Bar-Ilan University, Ramat-Gan, IsraelBackground: Colon cancer is one of the major causes of death in the Western world. Early detection significantly improves long-term survival for patients with the disease. Near-infrared (NIR fluorescent nanoparticles hold great promise as contrast agents for tumor detection. NIR offers several advantages for bioimaging compared with fluorescence in the visible spectrum, ie, lower autofluorescence of biological tissues, lower absorbance, and consequently deeper penetration into biomatrices.Methods and results: NIR fluorescent iron oxide nanoparticles with a narrow size distribution were prepared by nucleation, followed by controlled growth of thin iron oxide films onto cyanine NIR dye conjugated gelatin-iron oxide nuclei. For functionalization, and in order to increase the NIR fluorescence intensity, the NIR fluorescent iron oxide nanoparticles obtained were coated with human serum albumin containing cyanine NIR dye. Leakage of the NIR dye from these nanoparticles into phosphate-buffered saline solution containing 4% albumin was not detected. The work presented here is a feasibility study to test the suitability of iron oxide-human serum albumin NIR fluorescent nanoparticles for optical detection of colon cancer. It demonstrates that encapsulation of NIR fluorescent dye within these nanoparticles significantly reduces photobleaching of the dye. Tumor-targeting ligands, peanut agglutinin and anticarcinoembryonic antigen antibodies (αCEA, were covalently conjugated with the NIR fluorescent iron oxide-human serum albumin nanoparticles via a poly(ethylene glycol spacer. Specific colon tumor detection was demonstrated in chicken embryo and mouse models for both nonconjugated and the peanut agglutinin-conjugated or αCEA-conjugated NIR fluorescent iron oxide-human serum albumin

  11. The effect of near-infrared fluorescence conjugation on the anti-cancer potential of cetuximab.

    Science.gov (United States)

    Yun, Ji Young; Hyun, Byung-Hwa; Nam, Sang Yoon; Yun, Young Won; Lee, Hu-Jang; Lee, Beom-Jun

    2018-03-01

    This study investigated the anti-cancer potential of a near-infrared fluorescence (NIRF) molecule conjugated with Cetuximab (Cetuximab-NIRF) in six-week-old female BALB/c athymic (nu+/nu+) nude mice. A431 cells were cultured and injected into the animals to induce solid tumors. Paclitaxel (30 mg/kg body weight (BW)), Cetuximab (1 mg/kg BW), and Cetuximab-NIRF (0.25, 0.5 and 1.0 mg/kg BW) were intraperitoneally injected twice a week into the A431 cell xenografts of the nude mice. Changes in BW, tumor volume and weight, fat and lean mass, and diameter of the peri-tumoral blood vessel were determined after two weeks. Tumor volumes and weights were significantly decreased in the Cetuximab-NIRF (1 mg/kg BW) group compared with the control group ( P <0.001). Lean mass and total body water content were also conspicuously reduced in the Cetuximab-NIRF (1 mg/kg BW) group compared with the vehicle control group. Peri-tumoral blood vessel diameters were very thin in the Cetuximab-NIRF groups compared with those of the paclitaxel group. These results indicate that the conjugation of Cetuximab with NIRF does not affect the anti-cancer potential of Cetuximab and NIRF can be used for molecular imaging in cancer treatments.

  12. Fabrication of multicolor fluorescent polyvinyl alcohol through surface modification with conjugated polymers by oxidative polymerization

    Science.gov (United States)

    Hai, Thien An Phung; Sugimoto, Ryuichi

    2018-06-01

    A simple method for the preparation of multicolor polyvinyl alcohol (PVA) by chemical oxidative polymerization is introduced. The PVA surface was successfully modified with conjugated polymers composed of 3-hexylthiophene (3HT) and fluorene (F). The incorporation of the 3HT/F copolymer onto the PVA surface was confirmed by Fourier-transform infrared (FT-IR), ultraviolet-visible (UV-vis), and fluorescence spectroscopies, X-ray diffraction (XRD), as well as thermogravimetric analysis (TGA), contact angle, and field-emission scanning electron microscopy (FE-SEM) coupled with energy dispersive X-ray (EDX) analysis. Different 3HT/F ratios on the PVA surface result in optical properties that include multicolor-emission and absorption behavior. The color of the resultant (3HT/F)-g-PVA shifted from red to blue, and the quantum yield increased with increasing F content. The surface hydrophobicity of the modified PVA increased significantly through grafting with the conjugated polymers, with the water contact angle increasing by 30° compared to pristine PVA. The PVA XRD peaks were less intense following surface modification. Thermogravimetric analyses reveal that the thermal stability of the PVA decreases as a result of grafting with the 3HT/F copolymers.

  13. Enhanced spatial resolution in fluorescence molecular tomography using restarted L1-regularized nonlinear conjugate gradient algorithm.

    Science.gov (United States)

    Shi, Junwei; Liu, Fei; Zhang, Guanglei; Luo, Jianwen; Bai, Jing

    2014-04-01

    Owing to the high degree of scattering of light through tissues, the ill-posedness of fluorescence molecular tomography (FMT) inverse problem causes relatively low spatial resolution in the reconstruction results. Unlike L2 regularization, L1 regularization can preserve the details and reduce the noise effectively. Reconstruction is obtained through a restarted L1 regularization-based nonlinear conjugate gradient (re-L1-NCG) algorithm, which has been proven to be able to increase the computational speed with low memory consumption. The algorithm consists of inner and outer iterations. In the inner iteration, L1-NCG is used to obtain the L1-regularized results. In the outer iteration, the restarted strategy is used to increase the convergence speed of L1-NCG. To demonstrate the performance of re-L1-NCG in terms of spatial resolution, simulation and physical phantom studies with fluorescent targets located with different edge-to-edge distances were carried out. The reconstruction results show that the re-L1-NCG algorithm has the ability to resolve targets with an edge-to-edge distance of 0.1 cm at a depth of 1.5 cm, which is a significant improvement for FMT.

  14. Anti-VEGF antibody conjugated CdHgTe quantum dots as a fluorescent probe for imaging in living mouse

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Lili; Cui, Hongjing [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing (China); Liu, Yu [Department of Biochemistry, School of Life Science and Technology, China Pharmaceutical University, Nanjing (China); Zhong, Wenying, E-mail: wyzhong@cpu.edu.cn [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing (China); Key laboratory of Biomedical Functional Materials, China Pharmaceutical University, Nanjing (China)

    2016-05-15

    The dual-function anti-VEGF antibody conjugated CdHgTe quantum dots with good targeting property was successfully prepared. In this system, anti-VEGF antibody is not only a target agent but also a therapeutic drug. The anti-VEGF antibody conjugated near-infrared quantum dots can achieve the purposes of detection and treatment at the same time. As-prepared dual-function fluorescent probe in this work has been successfully applied for in vivo and in vitro imaging, which is promising in rapid tumor detection.

  15. Development and characterization of glutathione-conjugated albumin nanoparticles for improved brain delivery of hydrophilic fluorescent marker.

    Science.gov (United States)

    Patel, Prerak J; Acharya, Niyati S; Acharya, Sanjeev R

    2013-01-01

    The glutathione-conjugated bovine serum albumin (BSA) nanoparticles were constructed in the present exploration as a novel biodegradable carrier for brain-specific drug delivery with evaluation of its in vitro and in vivo delivery properties. BSA nanocarriers were activated and conjugated to the distal amine functions of the glutathione via carbodiimide chemistry using EDAC as a mediator. These nanoparticles were characterized for particle shape, average size, SPAN value, drug entrapment and in vitro drug release. Further, presence of glutathione on the surface of BSA nanoparticles was confirmed by Ellman's assay, which has suggested that approximately 750 units of glutathione were conjugated per BSA nanoparticle. To evaluate the brain delivery properties of the glutathione-conjugated BSA nanoparticles fluorescein sodium was used as a model hydrophilic compound. Permeability and neuronal uptake properties of developed formulations were evaluated against the MDCK-MDR1 endothelial and neuro-glial cells, respectively. The permeability of glutathione-conjugated BSA nanoparticles across the monolayer of MDCK-MDR1 endothelial tight junction was shown significantly higher than that of unconjugated nanoparticles and fluorescein sodium solution. Similarly, glutathione-conjugated nanoparticles exhibited considerably higher uptake by neuro-glial cells which was inferred by high fluorescence intensity under microscope in comparison to unconjugated nanoparticles and fluorescein sodium solution. Following an intravenous administration, nearly three folds higher fluorescein sodium was carried to the rat brain by glutathione-conjugated nanoparticles as compared to unconjugated nanoparticles. The significant in vitro and in vivo results suggest that glutathione-conjugated BSA nanoparticles is a promising brain drug delivery system with low toxicity.

  16. Fluorescent polystyrene photonic crystals self-assembled with water-soluble conjugated polyrotaxanes

    Directory of Open Access Journals (Sweden)

    Francesco Di Stasio

    2013-10-01

    Full Text Available We demonstrate control of the photoluminescence spectra and decay rates of water-soluble green-emitting conjugated polyrotaxanes by incorporating them in polystyrene opals with a stop-band spectrally tuned on the rotaxane emission (405–650 nm. We observe a suppression of the luminescence within the photonic stop-band and a corresponding enhancement of the high-energy edge (405–447 nm. Time-resolved measurements reveal a wavelength-dependent modification of the emission lifetime, which is shortened at the high-energy edge (by ∼11%, in the range 405–447 nm, but elongated within the stop-band (by ∼13%, in the range 448–482 nm. We assign both effects to the modification of the density of photonic states induced by the photonic crystal band structure. We propose the growth of fluorescent composite photonic crystals from blends of “solvent-compatible” non-covalently bonded nanosphere-polymer systems as a general method for achieving a uniform distribution of polymeric dopants in three-dimensional self-assembling photonic structures.

  17. Antibiotic Conjugated Fluorescent Carbon Dots as a Theranostic Agent for Controlled Drug Release, Bioimaging, and Enhanced Antimicrobial Activity

    Directory of Open Access Journals (Sweden)

    Mukeshchand Thakur

    2014-01-01

    Full Text Available A novel report on microwave assisted synthesis of bright carbon dots (C-dots using gum arabic (GA and its use as molecular vehicle to ferry ciprofloxacin hydrochloride, a broad spectrum antibiotic, is reported in the present work. Density gradient centrifugation (DGC was used to separate different types of C-dots. After careful analysis of the fractions obtained after centrifugation, ciprofloxacin was attached to synthesize ciprofloxacin conjugated with C-dots (Cipro@C-dots conjugate. Release of ciprofloxacin was found to be extremely regulated under physiological conditions. Cipro@C-dots were found to be biocompatible on Vero cells as compared to free ciprofloxacin (1.2 mM even at very high concentrations. Bare C-dots (∼13 mg mL−1 were used for microbial imaging of the simplest eukaryotic model—Saccharomyces cerevisiae (yeast. Bright green fluorescent was obtained when live imaging was performed to view yeast cells under fluorescent microscope suggesting C-dots incorporation inside the cells. Cipro@C-dots conjugate also showed enhanced antimicrobial activity against both model gram positive and gram negative microorganisms. Thus, the Cipro@C-dots conjugate paves not only a way for bioimaging but also an efficient new nanocarrier for controlled drug release with high antimicrobial activity, thereby serving potential tool for theranostics.

  18. Label-Free Fluorescent Detection of Trypsin Activity Based on DNA-Stabilized Silver Nanocluster-Peptide Conjugates

    Directory of Open Access Journals (Sweden)

    Cai-Xia Zhuo

    2016-11-01

    Full Text Available Trypsin is important during the regulation of pancreatic exocrine function. The detection of trypsin activity is currently limited because of the need for the substrate to be labeled with a fluorescent tag. A label-free fluorescent method has been developed to monitor trypsin activity. The designed peptide probe consists of six arginine molecules and a cysteine terminus and can be conjugated to DNA-stabilized silver nanoclusters (DNA-AgNCs by Ag-S bonding to enhance fluorescence. The peptide probe can also be adsorbed to the surface of graphene oxide (GO, thus resulting in the fluorescence quenching of DNA-AgNCs-peptide conjugate because of Förster resonance energy transfer. Once trypsin had degraded the peptide probe into amino acid residues, the DNA-AgNCs were released from the surface of GO, and the enhanced fluorescence of DNA-AgNCs was restored. Trypsin can be determined with a linear range of 0.0–50.0 ng/mL with a concentration as low as 1 ng/mL. This label-free method is simple and sensitive and has been successfully used for the determination of trypsin in serum. The method can also be modified to detect other proteases.

  19. Synthesis of highly water-soluble fluorescent conjugated glycopoly(p-phenylene)s for lectin and Escherichia coli.

    Science.gov (United States)

    Xue, Cuihua; Jog, Sonali P; Murthy, Pushpalatha; Liu, Haiying

    2006-09-01

    Two facile, convenient, and versatile synthetic approaches are used to covalently attach carbohydrate residues to conjugated poly(p-phenylene)s (PPPs) for highly water-soluble PPPs bearing alpha-mannopyranosyl and beta-glucopyranosyl pendants (polymers A and B), which highly fluoresce in phosphate buffer (pH 7.0). The post-polymerization functionalization approach is to treat bromo-bearing PPP (polymer 1) with 1-thiolethyl-alpha-D-mannose tetraacetate or 1-thiol-beta-D-glucose tetraacetate in THF solution in the presence of K(2)CO(3) at room temperature through formation of thioether bridges, affording polymer 2a or 2b. The prepolymerization functionalization approach is to polymerize a well-defined sugar-carrying monomer, affording polymer 2a. Polymers 2a and 2b were deacetylated under Zemplén conditions in methanol and methylene chloride containing sodium methoxide, affording polymers A and B, respectively. The multivalent display of carbohydrates on the fluorescent conjugated glycopolymer overcomes the characteristic low binding affinity of the individual carbohydrates to their receptor proteins. Titration of concanavalin A (Con A) to alpha-mannose-bearing polymer A resulted in significant fluorescent quenching of the polymer with Stern-Volmer quenching constant of 4.5 x 10(7). Incubation of polymer A with Escherichia coli (E. coli) lead to formation of fluorescently stained bacterial clusters. Beta-glucose-bearing polymer B displayed no response to Con A and E. coli.

  20. Imaging Amyloid Tissues Stained with Luminescent Conjugated Oligothiophenes by Hyperspectral Confocal Microscopy and Fluorescence Lifetime Imaging.

    Science.gov (United States)

    Nyström, Sofie; Bäck, Marcus; Nilsson, K Peter R; Hammarström, Per

    2017-10-20

    Proteins that deposit as amyloid in tissues throughout the body can be the cause or consequence of a large number of diseases. Among these we find neurodegenerative diseases such as Alzheimer's and Parkinson's disease afflicting primarily the central nervous system, and systemic amyloidosis where serum amyloid A, transthyretin and IgG light chains deposit as amyloid in liver, carpal tunnel, spleen, kidney, heart, and other peripheral tissues. Amyloid has been known and studied for more than a century, often using amyloid specific dyes such as Congo red and Thioflavin T (ThT) or Thioflavin (ThS). In this paper, we present heptamer-formyl thiophene acetic acid (hFTAA) as an example of recently developed complements to these dyes called luminescent conjugated oligothiophenes (LCOs). hFTAA is easy to use and is compatible with co-staining in immunofluorescence or with other cellular markers. Extensive research has proven that hFTAA detects a wider range of disease associated protein aggregates than conventional amyloid dyes. In addition, hFTAA can also be applied for optical assignment of distinct aggregated morphotypes to allow studies of amyloid fibril polymorphism. While the imaging methodology applied is optional, we here demonstrate hyperspectral imaging (HIS), laser scanning confocal microscopy and fluorescence lifetime imaging (FLIM). These examples show some of the imaging techniques where LCOs can be used as tools to gain more detailed knowledge of the formation and structural properties of amyloids. An important limitation to the technique is, as for all conventional optical microscopy techniques, the requirement for microscopic size of aggregates to allow detection. Furthermore, the aggregate should comprise a repetitive β-sheet structure to allow for hFTAA binding. Excessive fixation and/or epitope exposure that modify the aggregate structure or conformation can render poor hFTAA binding and hence pose limitations to accurate imaging.

  1. A Pyrene-Linked Cavity within a β-Barrel Protein Promotes an Asymmetric Diels-Alder Reaction.

    Science.gov (United States)

    Himiyama, Tomoki; Taniguchi, Naomasa; Kato, Shunsuke; Onoda, Akira; Hayashi, Takashi

    2017-10-23

    A unique π-expanded reaction cavity tethering a polycyclic moiety which provides a platform for substrate binding was constructed within the robust β-barrel structure of nitrobindin (NB). NB variants with cavities of different sizes and shapes are coupled with N-(1-pyrenyl)maleimide (Pyr) to prepare a series of NB-Pyr conjugates. The orientation of the pyrene moiety is fixed within the cavity by the coupling reaction. The fluorescent quenching analysis of NB-Pyr indicates that azachalcone (aza), which is a dienophile for a Diels-Alder (DA) reaction, is efficiently incorporated within the pyrene-linked reaction cavity by the aromatic interaction. The DA reaction between aza and cyclopentadiene proceeds within the reaction cavity of NB-Pyr in the presence of Cu II ion in high yield and high enantio- and regioselectivity. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Goat anti-rabbit IgG conjugated fluorescent dye-doped silica nanoparticles for human breast carcinoma cell recognition.

    Science.gov (United States)

    Chen, Min-Yan; Chen, Ze-Zhong; Wu, Ling-Ling; Tang, Hong-Wu; Pang, Dai-Wen

    2013-11-12

    We report an indirect method for cancer cell recognition using photostable fluorescent silica nanoprobes as biological labels. The dye-doped fluorescent silica nanoparticles were synthesized using the water-in-oil (W/O) reverse microemulsion method. The silica matrix was produced by the controlled hydrolysis of tetraethylorthosilicate (TEOS) in water nanodroplets with the initiation of ammonia (NH3·H2O). Fluorescein isothiocyanate (FITC) or rhodamine B isothiocyanate conjugated with dextran (RBITC-Dextran) was doped in silica nanoparticles (NPs) with a size of 60 ± 5 nm as a fluorescent signal element by covalent bonding and steric hindrance, respectively. The secondary antibody, goat anti-rabbit IgG, was conjugated on the surface of the PEG-terminated modified FITC-doped or RBITC-Dextran-doped silica nanoparticles (PFSiNPs or PBSiNPs) by covalent binding to the PEG linkers using the cyanogen bromide method. The concentrations of goat anti-rabbit IgG covering the nanoprobes were quantified via the Bradford method. In the proof-of-concept experiment, an epithelial cell adhesion molecule (EpCAM) on the human breast cancer SK-Br-3 cell surface was used as the tumor marker, and the nanoparticle functionalized with rabbit anti-EpCAM antibody was employed as the nanoprobe for cancer cell recognition. Compared with fluorescent dye labeled IgG (FITC-IgG and RBITC-IgG), the designed nanoprobes display dramatically increased stability of fluorescence as well as photostability under continuous irradiation.

  3. Pyrene As a New Detector for Determining the Composition of Silver Nanoparticle Dispersions in Aqueous Solutions

    Science.gov (United States)

    Romanovskaya, G. I.; Kazakova, S. Yu.; Koroleva, M. V.; Zuev, B. K.

    2018-03-01

    It is proposed that the fluorescence of monomeric molecules of pyrene in solid matrices or in concentrated micellar solutions be used as a detector for determining the compositional homogeneity of silver nanoparticle (NP) dispersions in aqueous solutions synthesized in different ways. It is found that the morphology of silver NPs affects the change in the fluorescence intensity of monomeric molecules of pyrene in a certain (violet or blue) region of the pyrene optical spectrum. The observed phenomenon is attributed to the resonance of electronic transitions in the monomeric molecules of pyrene in regions with plasmon oscillations in silver nanoparticles. A new way of obtaining fluorescent silver NPs is found.

  4. Conjugated polymer dots for ultra-stable full-color fluorescence patterning.

    Science.gov (United States)

    Chang, Kaiwen; Liu, Zhihe; Chen, Haobin; Sheng, Lan; Zhang, Sean Xiao-An; Chiu, Daniel T; Yin, Shengyan; Wu, Changfeng; Qin, Weiping

    2014-11-12

    Stable full-color fluorescence patterning are achieved by multicolor polymer-dot inks. The fluorescent patterns show extraordinary stability upon various treatments, offering a superior combination of bright fluorescence, excellent photostability, chemical resistance, and eco-friendship. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Micellar enhanced spectrofluorimetric methods: application to the determination of pyrene

    Energy Technology Data Exchange (ETDEWEB)

    Singh, H.; Hinze, W.L.

    1982-01-01

    The effects of cationic hexadecyltrimethylammonium chloride (CTAC), nonionic polyoxyethylene(9.5)p-1,1,3,3-tetramethylbutylphenol, Triton X-100 (TX-100), and anionic sodium dodecylsulfate (NaLS) surfactant micelles upon the spectrofluorimetric determination of pyrene is described. It was found that the intensity of the pyrene fluorescence is enhanced from 3 to 16 times in the presence of the micellar systems. Possible reasons for this micellar induced enhanced fluorescence are discussed. The spectral parameters, fluorescence lifetimes, quantum yields, lower detection limits, and analytical figures of merit for pyrene in CTAC, NaLS, TX-100, ethanol, and water are compared. The detection limit of pyrene in the presence of micelles (approx. 1.0 x 10/sup -10/ M) is about an order of magnitude lower than that possible in alcohol alone. A brief discussion on the predicted general applicability of this new technique in fluorimetric analysis is also given. 4 figures, 2 tables.

  6. FRET based integrated pyrene-AgNPs system for detection of Hg (II) and pyrene dimer: Applications to environmental analysis

    Science.gov (United States)

    Walekar, Laxman S.; Hu, Peidong; Vafaei Molamahmood, Hamed; Long, Mingce

    2018-06-01

    The integrated system of pyrene and cetyltrimethyl ammonium bromide (CTAB) capped silver nanoparticles (AgNPs) with a distance (r) of 2.78 nm has been developed for the detection of Hg (II) and pyrene dimer. The interaction between pyrene and AgNPs results in the fluorescence quenching of pyrene due to the energy transfer, whose mechanism can be attributed to the Forster Resonance Energy Transfer (FRET) supported by experimental observation and theoretical calculations. The developed probe shows a highly selective and sensitive response towards Hg (II) probably due to the amalgam formation, which results in the fluorescence recovery (90%) of pyrene and color change of solution from yellowish brown to colorless. The addition of Hg (II) may increase the distance between pyrene and AgNPs undergoes the 'FRET OFF' process. This system gives a selective response towards Hg (II) over other competing metal ions. Under the optimal condition, the system offers good linearity between 0.1 and 0.6 μg mL-1 with a detection limit of 62 ng mL-1. In addition, the system also provides an effective platform for detection of pyrene in its dimer form even at very low concentrations (10 ng mL-1) on the surface of AgNPs. Therefore, it could be used as effective alternatives for the detection of Hg (II) as well as pyrene simultaneously.

  7. Detection of bisphenol A in food packaging based on fluorescent conjugated polymer PPESO3 and enzyme system.

    Science.gov (United States)

    Huang, Hui; Li, Yongxin; Liu, Jintong; Tong, Jin; Su, Xingguang

    2015-10-15

    Bisphenol A (BPA) is a kind of carcinogen, which can interfere with the body's endocrine system. In this paper, a new kind of fluorescent sensor for BPA detection was established based on the fluorescent conjugated polymer PPESO3. The oxidative product of BPA is able to quench PPESO3 in the presence of HRP and H2O2, and the quenched PL intensity of PPESO3 was proportionally to the concentration of BPA in the range of 1-100 μmol/L with a detection limit of 4 × 10(-7) mol/L. The proposed method has been applied to detect BPA in eight food packaging samples with satisfactory results. The proposed method has the potential for the assay of BPA in food or food packaging samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Design of peptide-conjugated glycol chitosan nanoparticles for near infrared fluorescent (NIRF) in vivo imaging of bladder tumors

    Science.gov (United States)

    Key, Jaehong; Dhawan, Deepika; Knapp, Deborah W.; Kim, Kwangmeyung; Kwon, Ick Chan; Choi, Kuiwon; Leary, James F.

    2012-03-01

    Enhanced permeability and retention (EPR) effects for tumor treatment have been utilized as a representative strategy to accumulate untargeted nanoparticles in the blood vessels around tumors. However, the EPR effect itself was not sufficient for the nanoparticles to penetrate into cancer cells. For the improvement of diagnosis and treatment of cancer using nanoparticles, many more nanoparticles need to specifically enter cancer cells. Otherwise, can leave the tumor area and not contribute to treatment. In order to enhance the internalization process, specific ligands on nanoparticles can help their specific internalization in cancer cells by receptor-mediated endocytosis. We previously developed glycol chitosan based nanoparticles that suggested a promising possibility for in vivo tumor imaging using the EPR effect. The glycol chitosan nanoparticles showed a long circulation time beyond 1 day and they were accumulated predominantly in tumor. In this study, we evaluated two peptides for specific targeting and better internalization into urinary bladder cancer cells. We conjugated the peptides on to the glycol chitosan nanoparticles; the peptide-conjugated nanoparticles were also labeling with near infrared fluorescent (NIRF) dye, Cy5.5, to visualize them by optical imaging in vivo. Importantly real-time NIRF imaging can also be used for fluorescence (NIRF)-guided surgery of tumors beyond normal optical penetration depths. The peptide conjugated glycol chitosan nanoparticles were characterized with respect to size, stability and zeta-potential and compared with previous nanoparticles without ligands in terms of their internalization into bladder cancer cells. This study demonstrated the possibility of our nanoparticles for tumor imaging and emphasized the importance of specific targeting peptides.

  9. Novel poly(triphenylamine-alt-fluorene) with asymmetric hexaphenylbenzene and pyrene moieties: synthesis, fluorescence, flexible near-infrared electrochromic devices and theoretical investigation

    KAUST Repository

    Wang, Po-I.; Shie, Wan-Ru; Jiang, Jyh-Chiang; Li, Lain-Jong; Liaw, Der-Jang

    2016-01-01

    . The conjugated polymer had a weight-average molecular weight of 5.8 × 104 g mol-1 with a polydispersity index of 2.5 characterized by gel permeation chromatography (GPC). HPBPYFL6 showed good solubility in common organic solvents such as NMP, THF, toluene

  10. A Conjugated Aptamer-Gold Nanoparticle Fluorescent Probe for Highly Sensitive Detection of rHuEPO-α

    Directory of Open Access Journals (Sweden)

    Zhaoyang Zhang

    2011-11-01

    Full Text Available We present here a novel conjugated aptamer-gold nanoparticle (Apt-AuNPs fluorescent probe and its application for specific detection of recombinant human erythropoietin-α (rHuEPO-α. In this nanobiosensor, 12 nm AuNPs function as both a nano-scaffold and a nano-quencher (fluorescent energy acceptor, on the surface of which the complementary sequences are linked (as cODN-AuNPs and pre-hybridized with carboxymethylfluorescein (FAM-labeled anti-rHuEPO-α aptamers. Upon target protein binding, the aptamers can be released from the AuNP surface and the fluorescence signal is restored. Key variables such as the length of linker, the hybridization site and length have been designed and optimized. Full performance evaluation including sensitivity, linear range and interference substances are also described. This nanobiosensor provides a promising approach for a simple and direct quantification of rHuEPO-α concentrations as low as 0.92 nM within a few hours.

  11. Reactions of the hydrated electron with pyrene in lipid bilayer vesicles

    International Nuclear Information System (INIS)

    Schnecke, W.; Graetzel, M.; Henglein, A.

    1977-01-01

    Pyrene and some pyrene derivatives were solubilized in bilayer vesicles of lecithin and the rates of lecithin and the rates of reaction with the hydrated electron investigated. The concentration of the vesicles was 1.3 x 10 -7 M, that of pyrene 10 -6 - 10 -4 M. The rate constant decreases with increasing pyrene concentration. The effect is explained by the highly inhomogeneous distribution of pyrene molecules in the solutions. Only those pyrene molicules are reactive that reside close to the outer surface of the vesicles. The anions of pyrene formed disappear in a second order process. It is concluded that the anions are rapidly detached from their vesicular carriers and react with each other in the aqueous phase. Fluorescence, light scattering and electron microscopic investigations were also carried out to obtain information about the properties of the vesicles used. (orig.) [de

  12. Determination of catecholamine in human serum by a fluorescent quenching method based on a water-soluble fluorescent conjugated polymer-enzyme hybrid system.

    Science.gov (United States)

    Huang, Hui; Gao, Yuan; Shi, Fanping; Wang, Guannan; Shah, Syed Mazhar; Su, Xingguang

    2012-03-21

    In this paper, a sensitive water-soluble fluorescent conjugated polymer biosensor for catecholamine (dopamine DA, adrenaline AD and norepinephrine NE) was developed. In the presence of horse radish peroxidase (HRP) and H(2)O(2), catecholamine could be oxidized and the oxidation product of catecholamine could quench the photoluminescence (PL) intensity of poly(2,5-bis(3-sulfonatopropoxy)-1,4-phenylethynylenealt-1,4-poly(phenylene ethynylene)) (PPESO(3)). The quenching PL intensity of PPESO(3) (I(0)/I) was proportional to the concentration of DA, AD and NE in the concentration ranges of 5.0 × 10(-7) to 1.4 × 10(-4), 5.0 × 10(-6) to 5.0 × 10(-4), and 5.0 × 10(-6) to 5.0 × 10(-4) mol L(-1), respectively. The detection limit for DA, AD and NE was 1.4 × 10(-7) mol L(-1), 1.0 × 10(-6) and 1.0 × 10(-6) mol L(-1), respectively. The PPESO(3)-enzyme hybrid system based on the fluorescence quenching method was successfully applied for the determination of catecholamine in human serum samples with good accuracy and satisfactory recovery. The results were in good agreement with those provided by the HPLC-MS method.

  13. Cholesterol-conjugated supramolecular assemblies of low generations polyamidoamine dendrimers for enhanced EGFP plasmid DNA transfection

    Energy Technology Data Exchange (ETDEWEB)

    Golkar, Nasim; Samani, Soliman Mohammadi; Tamaddon, Ali Mohammad, E-mail: amtamadon@gmail.com [Shiraz University of Medical Sciences, Department of Pharmaceutics, School of Pharmacy (Iran, Islamic Republic of)

    2016-05-15

    Aimed to prepare an enhanced gene delivery system with low cytotoxicity and high transfection efficiency, various cholesterol-conjugated derivates of low generation polyamidoamine (PAMAM) dendrimers were prepared. The conjugates were characterized by TNBS assay, FTIR, and {sup 1}H-NMR spectroscopy. Self-assembly of the dendrimer conjugates (G1-Chol, G2-Chol, and G3-Chol) was investigated by pyrene assay. Following formation of the complexes between enhanced green fluorescence protein plasmid and the dendrimer conjugates at various N (primary amine)/P (phosphate) mole ratios, plasmid condensation, biologic stability, cytotoxicity, and protein expression were investigated. The conjugates self-assembled into micellar dispersions with the critical micelle concentration values (<50 µg/ml) depending on the dendrimer generation and cholesterol/amine mole ratio. Cholesterol conjugation resulted in higher resistance of the condensed plasmid DNA in a competition assay with heparin sulfate. Also, the transfection efficiency was determined higher for the cholesterol conjugates than unmodified dendrimers in HepG2 cells, showing the highest for G2-Chol at 40 % degree of cholesterol modification (G2-Chol{sub 40 %}) among various dendrimer generations. Interestingly, such conjugate showed a complete protection of plasmid against serum nucleases. Our results confirmed that the cholesterol conjugation to PAMAM dendrimers of low generations bearing little cytotoxicity improves their several physicochemical and biological characteristics required for an enhanced delivery of plasmid DNA into cells.

  14. Dual partitioning and attachment effects of rhamnolipid on pyrene biodegradation under bioavailability restrictions

    International Nuclear Information System (INIS)

    Congiu, Eleonora; Parsons, John R.; Ortega-Calvo, José-Julio

    2015-01-01

    We investigated the effects of different bioavailability scenarios on the rhamnolipid-enhanced biodegradation of pyrene by the representative polycyclic aromatic hydrocarbon degrader Mycobacterium gilvum VM552. This biosurfactant enhanced biodegradation when pyrene was provided in the form of solid crystals; no effect was observed when the same amount of the chemical was preloaded on polydimethylsiloxane (PDMS). An enhanced effect was observed when pyrene was sorbed into soil but not with the dissolved compound. Synchronous fluorescence spectrophotometry and liquid scintillation were used to determine the phase exchange of pyrene. We also investigated the phase distribution of bacteria. Our results suggest that the rhamnolipid can enhance the biodegradation of pyrene by micellar solubilization and increase diffusive uptake. These mechanisms increase substrate acquisition by bacterial cells at exposure concentrations well above the half-saturation constant for active uptake. The moderate solubilization of pyrene from PDMS by the rhamnolipid and the prevention of cell attachment may explain the lack of enhancement for pyrene-preloaded PDMS. - Highlights: • Rhamnolipid biosurfactant can enhance the biodegradation of pyrene. • The enhancement depends on how the bacteria are exposed to the pollutant. • Rhamnolipid stimulates if pyrene is provided by dissolution from crystals. • No effect is observed if pyrene is provided by partitioning from a silicone polymer. • This lack of effect is due to the balance between enhanced dissolution and decreased cell attachment. - Rhamnolipid-enhanced biodegradation of pyrene may depend on the exposure regime. Moderate solubilization from difficult matrices and prevention of cell attachment may have no effect

  15. A Novel Molecular Fluorescent Technique for Imaging the Somatostatin Receptor 2, Using a DOTATOC Lanthanide Conjugate

    DEFF Research Database (Denmark)

    Andersen, Rune Wiik; Prakash, Vineet; Stensballe, Allan

    -functional DOTATOC component.                       METHOD AND MATERIALS            The chelation of Europium and Samarium to DOTATOC was proven using MALDI-TOF Mass Spectrometry. The rise in quantum yield between unchelated lanthanides and those bound by DOTATOC was examined using fluorescence spectroscopy...

  16. 3'-Pyrene-modified unlocked nucleic acids

    DEFF Research Database (Denmark)

    Ejlersen, Maria; Langkjær, Niels; Wengel, Jesper

    2017-01-01

    in the minor groove of DNA:DNA duplexes as confirmed by CD and UV/Vis absorption studies. Upon multiple incorporations of the monomer in single-stranded ONs, steady-state fluorescence emission studies revealed the formation of a pyrene excimer which in most cases was quenched upon duplex hybridization......, and fluorescence-based detection of mismatched hybridization was observed for some modified strand constitutions. Incorporation of the monomer in a triplex-forming oligonucleotide (TFO) strand lead to an increase of triplex melting temperature both at pH 6.0 and pH 7.0 for parallel triplexes - again an effect...

  17. Part-per-trillion level detection of estradiol by competitive fluorescence immunoassay using DNA/dye conjugate as antibody multiple labels.

    Science.gov (United States)

    Zhu, Shengchao; Zhang, Qin; Guo, Liang-Hong

    2008-08-22

    Fluorescent organic dyes are currently the standard signal-generating labels used in microarray quantification. However, new labeling strategies are needed to meet the demand for high sensitivity in the detection of low-abundance proteins and small molecules. In this report, a long-chain DNA/dye conjugate was used to attach multiple fluorescence labels on antibodies to improve signal intensity and immunoassay sensitivity. Compared with the 30 base-pair (bp) oligonucleotide used in our previous work [Q. Zhang, L.-H. Guo, Bioconjugate Chem. 18 (2007) 1668-1672], conjugation of a 219 bp DNA in solution with a fluorescent DNA binder SYBR Green I resulted in more than sixfold increase in signal intensity, consistent with the increase in bp number. In a direct immunoassay for the detection of goat anti-mouse IgG in a mouse IgG-coated 96-well plate, the long DNA conjugate label also produced higher fluorescence than the short one, accompanied by about 15-fold improvement in the detection limit. To demonstrate its advantage in real applications, the DNA/dye conjugate was employed in the competitive immunoassay of 17beta-estradiol, a clinically and environmentally important analyte. The biotin-terminated DNA was attached to biotinylated anti-estradiol antibody through the biotin/streptavidin/biotin bridge after the immuno-reaction was completed, followed by conjugation with SYBR Green I. The limit of detection for 17beta-estradiol is 1.9 pg mL(-1), which is 200-fold lower than the assay using fluorescein-labeled antibodies. The new multiple labeling strategy uses readily available reagents, and is also compatible with current biochip platform. It has great potential in the sensitive detection of protein and antibody microarrays.

  18. Fluorescent strategy based on cationic conjugated polymer fluorescence resonance energy transfer for the quantification of 5-(hydroxymethyl)cytosine in genomic DNA.

    Science.gov (United States)

    Hong, Tingting; Wang, Tianlu; Guo, Pu; Xing, Xiwen; Ding, Fei; Chen, Yuqi; Wu, Jinjun; Ma, Jingwei; Wu, Fan; Zhou, Xiang

    2013-11-19

    DNA methylation is dynamically reprogrammed during early embryonic development in mammals. It can be explained partially by the discovery of 5-(hydroxymethyl)cytosine (5-hmC), 5-formylcytosine (5-fC), and 5-carboxylcytosine (5-caC), which are identified as key players involved in both active and passive demethylation pathways. As one of the ten-eleven translocation oxidation products, 5-hmC was found relatively abundant in neuron cells and embryonic stem cells. Herein we report a new method for 5-hmC quantification in genomic DNA based on CCP-FRET (cationic conjugated polymers act as the energy donor and induce fluorescence resonance energy transfer) assay combined with KRuO4 oxidation. 5-hmC in genomic DNA can be selectively transformed into 5-fC by the oxidation of KRuO4 and then labeled with hydroxylamine-BODIPY (BODIPY = 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) fluorophore through the reaction between 5-fC and hydroxylamine-BODIPY. After the fluorescently labeled DNA was captured by CCP through electrostatic interactions, a significant FRET between CCP and hydroxylamine-BODIPY fluorophore was observed. This CCP-FRET-based assay benefits from light-harvesting, large Stokes shift, and optical signal amplification properties of the CCP. Furthermore, this CCP-FRET-based assay was quite successfully demonstrated for the 5-hmC quantification in three types of cells (mESc, HeLa, HEK 293T), providing a much more convenient choice for 5-hmC quantification in genomic DNA.

  19. Aggregation behavior of sodium lauryl ether sulfate with a positively bicharged organic salt and effects of the mixture on fluorescent properties of conjugated polyelectrolytes.

    Science.gov (United States)

    Tang, Yongqiang; Liu, Zhang; Zhu, Linyi; Han, Yuchun; Wang, Yilin

    2015-02-24

    The aggregation behavior of anionic single-chain surfactant sodium lauryl ether sulfate containing three ether groups (SLE3S) with positively bicharged organic salt 1,2-bis(2-benzylammoniumethoxy)ethane dichloride (BEO) has been investigated in aqueous solution, and the effects of the BEO/SLE3S aggregate transitions on the fluorescent properties of anionic conjugated polyelectrolyte MPS-PPV with a larger molecular weight and cationic conjugated oligoelectrolyte DAB have been evaluated. Without BEO, SLE3S does not affect the fluorescent properties of MPS-PPV and only affects the fluorescent properties of DAB at a higher SLE3S concentration. With the addition of BEO, SLE3S and BEO form gemini-like surfactant (SLE3S)2-BEO. When the BEO/SLE3S molar ratio is fixed at 0.25, with increasing the BEO/SLE3S concentration, the BEO/SLE3S mixture forms large, loosely arranged aggregates and then transforms to closely packed spherical aggregates and finally to long thread-like micelles. The photoluminescence (PL) intensity of MPS-PPV varies with the morphologies of the BEO/SLE3S aggregates, while the PL intensity of DAB is almost independent of the aggregate morphologies. The results demonstrate that gemini-like surfactants formed through intermolecular interactions can effectively adjust the fluorescent properties of conjugated polyelectrolytes.

  20. Light-Induced Fluorescence Modulation of Quantum Dot-Crystal Violet Conjugates: Stochastic Off-On-Off Cycles for Multicolor Patterning and Super-Resolution.

    Science.gov (United States)

    Jung, Sungwook; Park, Joonhyuck; Bang, Jiwon; Kim, Jae-Yeol; Kim, Cheolhee; Jeon, Yongmoon; Lee, Seung Hwan; Jin, Ho; Choi, Sukyung; Kim, Bomi; Lee, Woo Jin; Pack, Chan-Gi; Lee, Jong-Bong; Lee, Nam Ki; Kim, Sungjee

    2017-06-07

    Photoswitching or modulation of quantum dots (QDs) can be promising for many fields that include display, memory, and super-resolution imaging. However, such modulations have mostly relied on photomodulations of conjugated molecules in QD vicinity, which typically require high power of high energy photons at UV. We report a visible light-induced facile modulation route for QD-dye conjugates. QD crystal violets conjugates (QD-CVs) were prepared and the crystal violet (CV) molecules on QD quenched the fluorescence efficiently. The fluorescence of QD-CVs showed a single cycle of emission burst as they go through three stages of (i) initially quenched "off" to (ii) photoactivated "on" as the result of chemical change of CVs induced by photoelectrons from QD and (iii) back to photodarkened "off" by radical-associated reactions. Multicolor on-demand photopatterning was demonstrated using QD-CV solid films. QD-CVs were introduced into cells, and excitation with visible light yielded photomodulation from "off" to "on" and "off" by nearly ten fold. Individual photoluminescence dynamics of QD-CVs was investigated using fluorescence correlation spectroscopy and single QD emission analysis, which revealed temporally stochastic photoactivations and photodarkenings. Exploiting the stochastic fluorescence burst of QD-CVs, simultaneous multicolor super-resolution localizations were demonstrated.

  1. Aptamer-conjugated PEGylated quantum dots targeting epidermal growth factor receptor variant III for fluorescence imaging of glioma.

    Science.gov (United States)

    Tang, Jiaze; Huang, Ning; Zhang, Xiang; Zhou, Tao; Tan, Ying; Pi, Jiangli; Pi, Li; Cheng, Si; Zheng, Huzhi; Cheng, Yuan

    2017-01-01

    The extent of resection is a significant prognostic factor in glioma patients. However, the maximum safe resection level is difficult to determine due to the inherent infiltrative character of tumors. Recently, fluorescence-guided surgery has emerged as a new technique that allows safe resection of glioma. In this study, we constructed a new kind of quantum dot (QD)-labeled aptamer (QD-Apt) nanoprobe by conjugating aptamer 32 (A32) to the QDs surface, which can specially bind to the tumors. A32 is a single-stranded DNA capable of binding to the epidermal growth factor receptor variant III (EGFRvIII) specially distributed on the surface of glioma cells. To detect the expression of EGFRvIII in human brain tissues, 120 specimens, including 110 glioma tissues and 10 normal brain tissues, were examined by immunohistochemistry, and the results showed that the rate of positive expression of EGFRvIII in the glioma tissues was 41.82%, and 0.00% in normal brain tissues. Besides, the physiochemical properties of QD-Apt nanoparticles (NPs) were thoroughly characterized. Biocompatibility of the NPs was evaluated, and the results suggested that the QD-Apt was nontoxic in vivo and vitro. Furthermore, the use of the QD-Apt in labeling glioma cell lines and human brain glioma tissues, and target gliomas in situ was also investigated. We found that not only could QD-Apt specially bind to the U87-EGFRvIII glioma cells but also bind to human glioma tissues in vitro. Fluorescence imaging in vivo with orthotopic glioma model mice bearing U87-EGFRvIII showed that QD-Apt could penetrate the blood-brain barrier and then selectively accumulate in the tumors through binding to EGFRvIII, and consequently, generate a strong fluorescence, which contributed to the margins of gliomas that were visualized clearly, and thus, help the surgeons realize the maximum safe resection of glioma. In addition, QD-Apt can also be applied in preoperative diagnosis and postoperative examination of glioma

  2. Fluorescence Chemosensory Determination of Cu2+ Using a New Rhodamine–Morpholine Conjugate

    Directory of Open Access Journals (Sweden)

    Zeinab Shekari

    2017-09-01

    Full Text Available A new rhodamine-B carbonyl-morpholine derivative (denoted as RECM was prepared by a two-step synthesis procedure. The employed method allowed a lactam ring development of rhodamine-B and ethylenediamine to demonstrate a facile amide bond formation. The obtained RECM was confirmed by 1H NMR, 13C NMR, and mass spectrometry analysis. RECM was formed to detect copper ion (Cu2+ due to its problematic toxicity features in aquatic ecosystems. It showed a high selectivity toward Cu2+ in comparison with some environmentally relevant alkali, alkaline earth, and transition metal cations at 50 µM in acetonitrile. Moreover, non-fluorescent RECM showed fluorescence intensity and UV-Vis absorbance increases in the presence of Cu2+ with high linear dependent coefficients (R2 = 0.964 and R2 = 0.982 respectively as well as a color change from colorless to pink owing to the ring opening of the rhodamine spirolactam form. Binding capability experiments presented a clear 1:1 stoichiometry of RECM–Cu2+ complex with the binding constant (Ka as 2.25 × 104 M−1. The calculation of limits of detection (LOD was 0.21 µM based on the linear regression method, which is below the maximum contaminant level goal (MCLG value of Cu2+ (1.3 ppm equals to 20.46 µM in drinking water. These characteristics make the RECM a promising candidate for the real-time detection of toxic Cu2+ in environmental monitoring applications.

  3. Synthesis and Characterization of Anti-HER2 Antibody Conjugated CdSe/CdZnS Quantum Dots for Fluorescence Imaging of Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Takashi Jin

    2009-11-01

    Full Text Available The early detection of HER2 (human epidermal growth factor receptor 2 status in breast cancer patients is very important for the effective implementation of anti-HER2 antibody therapy. Recently, HER2 detections using antibody conjugated quantum dots (QDs have attracted much attention. QDs are a new class of fluorescent materials that have superior properties such as high brightness, high resistance to photo-bleaching, and multi-colored emission by a single-light source excitation. In this study, we synthesized three types of anti-HER2 antibody conjugated QDs (HER2Ab-QDs using different coupling agents (EDC/sulfo-NHS, iminothiolane/sulfo-SMCC, and sulfo-SMCC. As water-soluble QDs for the conjugation of antibody, we used glutathione coated CdSe/CdZnS QDs (GSH-QDs with fluorescence quantum yields of 0.23~0.39 in aqueous solution. Dispersibility, hydrodynamic size, and apparent molecular weights of the GSH-QDs and HER2Ab-QDs were characterized by using dynamic light scattering, fluorescence correlation spectroscopy, atomic force microscope, and size-exclusion HPLC. Fluorescence imaging of HER2 overexpressing cells (KPL-4 human breast cancer cell line was performed by using HER2Ab-QDs as fluorescent probes. We found that the HER2Ab-QD prepared by using SMCC coupling with partially reduced antibody is a most effective probe for the detection of HER2 expression in KPL-4 cells. We have also studied the size dependency of HER2Ab-QDs (with green, orange, and red emission on the fluorescence image of KPL-4 cells.

  4. Synthesis, characterization and photophysical study of ethynyl pyrene derivatives as promising materials for organic optoelectronics

    Energy Technology Data Exchange (ETDEWEB)

    Gama, Paola E.; Corrêa, Rodrigo J.; Garden, Simon J., E-mail: garden@iq.ufrj.br

    2015-05-15

    Two series of pyrene derivatives, phenylethynyl (4–6) and the previously unknown ethynylcyclohexanol (7–9), were prepared by Sonogashira cross-coupling reactions. The introduction of an increasing number of ethynyl substituents resulted in a progressive bathochromic shift in the absorption and emission spectra which culminated in an inversion of the nature of the first two excited states ({sup 1}L{sub a} and {sup 1}L{sub b}) of the tetra-substituted derivatives (6 and 9) relative to pyrene. In solution, only for the mono-cyclohexanolethynyl pyrene (7) a sufficiently concentrated solution could be obtained so as to observe the excimer. Additionally, the emission band ratio I{sub 1}/I{sub 3} for 7 was found to be moderately sensitive to the nature of the solvent and the ratio directly correlated with the Py scale. TDDFT calculations were used to explore the variation of the properties of the low lying excited states. Fluorescence emission in the solid state, with the appropriate choice of materials, covers the entire visible region of the electromagnetic spectrum due to static excimer emission. A massive red-shift for solid state photoluminescence from 9 resulted in emission at longer wavelength than the more highly conjugated 6. - Highlights: • Phenyl and cyclohexanol ethynylpyrene derivatives: photophysically compared. • Excimer formation and solvent dependent emission from cyclohexanolethynylpyrene. • Systematic red shifting of solid state photoluminescence from static excimers. • Massive red-shift in the solid state photoluminescence of 9. • TDDFT calculations: properties of the lowest singlet states, systematic comparison.

  5. Hybrid fluorescent nanoparticles fabricated from pyridine-functionalized polyfluorene-based conjugated polymer as reversible pH probes over a broad range of acidity-alkalinity

    International Nuclear Information System (INIS)

    Cui, Haijun; Chen, Ying; Li, Lianshan; Tang, Zhiyong; Wu, Yishi; Fu, Hongbing; Tian, Zhiyuan

    2014-01-01

    Conjugated polymer nanoparticles (CPNs) were developed based on a polyfluorene-based conjugated polymer with thiophene units carrying pyridyl moieties incorporated in the backbone of polymer chains (PFPyT). Hybrid CPNs fabricated from PFPyT and an amphiphilic polymer (NP1) displayed pH-sensitive fluorescence emission features in the range from pH 4.8 to 13, which makes them an attractive nanomaterial for wide range optical sensing of pH values. The fluorescence of hybrid CPNs based on chemically close polyfluorene derivatives without pyridyl moieties (NP3), in contrast, remains virtually unperturbed by pH values in the same range. The fluorescence emission features of NP1 underwent fully reversible changes upon alternating acidification/basification of aqueous dispersions of the CPNs and also displayed excellent repeatability. The observed pH sensing properties of NP1 are attributed to protonation/deprotonation of the nitrogen atoms of the pyridine moieties. This, in turn, leads to the redistribution of electron density of pyridine moieties and their participation in the π-conjugation within the polymer main chains. The optically transparent amphiphilic polymers also exerted significant influence on the pH sensing features of the CPNs, likely by acting as proton sponge and/or acid chaperone. (author)

  6. Labeling the oily core of nanocapsules and lipid-core nanocapsules with a triglyceride conjugated to a fluorescent dye as a strategy to particle tracking in biological studies

    Science.gov (United States)

    Fiel, Luana Almeida; Contri, Renata Vidor; Bica, Juliane Freitas; Figueiró, Fabrício; Battastini, Ana Maria Oliveira; Guterres, Sílvia Stanisçuaski; Pohlmann, Adriana Raffin

    2014-05-01

    The synthesis of novel fluorescent materials represents a very important step to obtain labeled nanoformulations in order to evaluate their biological behavior. The strategy of conjugating a fluorescent dye with triacylglycerol allows that either particles differing regarding supramolecular structure, i.e., nanoemulsions, nanocapsules, lipid-core nanocapsules, or surface charge, i.e., cationic nanocapsules and anionic nanocapsules, can be tracked using the same labeled material. In this way, a rhodamine B-conjugated triglyceride was obtained to prepare fluorescent polymeric nanocapsules. Different formulations were obtained, nanocapsules (NC) or lipid-core nanocapsules (LNC), using the labeled oil and Eudragit RS100, Eudragit S100, or poly(caprolactone) (PCL), respectively. The rhodamine B was coupled with the ricinolein by activating the carboxylic function using a carbodiimide derivative. Thin layer chromatography, proton nuclear magnetic resonance (1H-NMR), Fourier transform infrared spectroscopy (FTIR), UV-vis, and fluorescence spectroscopy were used to identify the new product. Fluorescent nanocapsule aqueous suspensions were prepared by the solvent displacement method. Their pH values were 4.6 (NC-RS100), 3.5 (NC-S100), and 5.0 (LNC-PCL). The volume-weighted mean diameter ( D 4.3) and polydispersity values were 150 nm and 1.05 (NC-RS100), 350 nm and 2.28 (NC-S100), and 270 nm and 1.67 (LNC-PCL). The mean diameters determined by photon correlation spectroscopy (PCS) ( z-average) were around 200 nm. The zeta potential values were +5.85 mV (NC-RS100), -21.12 mV (NC-S100), and -19.25 mV (LNC-PCL). The wavelengths of maximum fluorescence emission were 567 nm (NC-RS100 and LNC-PCL) and 574 nm (NC-S100). Fluorescence microscopy was used to evaluate the cell uptake (human macrophage cell line) of the fluorescent nanocapsules in order to show the applicability of the approach. When the cells were treated with the fluorescent nanocapsules, red emission was detected

  7. PYRENE INTERCALATING NUCLEIC ACIDS WITH A CARBON LINKER

    DEFF Research Database (Denmark)

    Østergaard, Michael E.; Wamberg, Michael Chr.; Pedersen, Erik Bjerregaard

    2011-01-01

    geminally attached. Fluorescence studies of this intercalating nucleic acid with the pyrene moieties inserted as a bulge showed formation of an excimer band. When a mismatch was introduced at the site of the intercalator, an excimer band was formed for the destabilized duplexes whereas an exciplex band...

  8. Conjugated polymer with carboxylate groups-Hg2 + system as a turn-on fluorescence probe for label-free detection of cysteine-containing compounds

    Science.gov (United States)

    Mi, Hongyu; Guan, Mingming; Liu, Jilin; Shan, Hongyan; Fei, Qiang; Huan, Yanfu; Feng, Guodong

    2017-04-01

    In this work, a turn on fluorescent sensor, based on Hg2 + coordination conjugated polymer, was developed to detect cysteine-containing compounds. The fluorescence of conjugated polymer (poly(2,5-bis (sodium 4-oxybutyrate) -1,4 - phenylethynylene-alt-1,4-phenyleneethynylene; PPE-OBS) would be quenched by Hg2 + because of the coordination-induced aggregation and electron transfers of PPE-OBS toward Hg2 +. When there were some cysteine-containing compounds in PPE-OBS-Hg2 + system, the fluorescence of PPE-OBS would be recovered. It indicated that the PPE-OBS-Hg2 + system could be used to detect cysteine-containing compounds. Under the optimized conditions, the experiment results showed that there were particularly linear range, high sensitivity and selectivity over other amino acids. The limit of detection (LOD) of cysteine (Cys), homocysteine (Hcy) and glutathione (GSH) were 0.725 μmol L- 1, 0.982 μmol L- 1 and 1.21 μmol L- 1 by using this sensor. In addition, Cys standard recovery in several green tea drink and honey samples was also demonstrated. The recovery of Cys was range from 96.3 to 105.0% and RSD was less than 3.25%. The satisfactory results demonstrated that the proposed method could be as a potential fluorescent method for determining cysteine-containing compounds in real samples.

  9. Aptamer-conjugated PEGylated quantum dots targeting epidermal growth factor receptor variant III for fluorescence imaging of glioma

    Directory of Open Access Journals (Sweden)

    Tang J

    2017-05-01

    Full Text Available Jiaze Tang,1 Ning Huang,1 Xiang Zhang,1,2 Tao Zhou,3 Ying Tan,1,4 Jiangli Pi,5 Li Pi,1 Si Cheng,6 Huzhi Zheng,5 Yuan Cheng1 1Department of Neurosurgery, The Second Affiliated Hospital of Chongqing Medical University, 2Chongqing Key Laboratory of Ultrasound Molecular Imaging, Institute of Ultrasound Imaging, 3Chongqing Key Laboratory of Biochemistry and Molecular Pharmacology, 4Institute of Life Sciences, Chongqing Medical University, 5Key Laboratory on Luminescent and Real-Time Analytical Chemistry, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, 6Department of Orthopaedics, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of China Abstract: The extent of resection is a significant prognostic factor in glioma patients. However, the maximum safe resection level is difficult to determine due to the inherent infiltrative character of tumors. Recently, fluorescence-guided surgery has emerged as a new technique that allows safe resection of glioma. In this study, we constructed a new kind of quantum dot (QD-labeled aptamer (QD-Apt nanoprobe by conjugating aptamer 32 (A32 to the QDs surface, which can specially bind to the tumors. A32 is a single-stranded DNA capable of binding to the epidermal growth factor receptor variant III (EGFRvIII specially distributed on the surface of glioma cells. To detect the expression of EGFRvIII in human brain tissues, 120 specimens, including 110 glioma tissues and 10 normal brain tissues, were examined by immunohistochemistry, and the results showed that the rate of positive expression of EGFRvIII in the glioma tissues was 41.82%, and 0.00% in normal brain tissues. Besides, the physiochemical properties of QD-Apt nanoparticles (NPs were thoroughly characterized. Biocompatibility of the NPs was evaluated, and the results suggested that the QD-Apt was nontoxic in vivo and vitro. Furthermore, the use of the QD-Apt in labeling

  10. Circularly polarized luminescence of helically assembled pyrene π-stacks on RNA and DNA duplexes.

    Science.gov (United States)

    Nakamura, Mitsunobu; Ota, Fuyuki; Takada, Tadao; Akagi, Kazuo; Yamana, Kazushige

    2018-05-01

    In this report, we describe the circularly polarized luminescence (CPL) of the RNA duplexes having one to four 2'-O-pyrene modified uridines (Upy) and the DNA duplexes having two, four, and six pyrene modified non-nucleosidic linkers (Py). Both the pyrene π-stack arrays formed on the RNA and DNA double helical structures exhibited pyrene excimer fluorescence. In the pyrene-modified RNA systems, the RNA duplex having four Upys gives CPL emission with g lum value of <0.01 at 480 nm. The structure of pyrene stacks on the RNA duplex may be rigidly regulated with increase in the Upy domains, which resulted in the CPL emission. In the DNA systems, the pyrene-modified duplexes containing two and four Pys exhibited CPL emission with g lum values of <0.001 at 505 nm. The pyrene π-stack arrays presented here show CPL emission. However, the g lum values are relatively small when compared with our previous system consisting of the pyrene-zipper arrays on RNA. © 2018 Wiley Periodicals, Inc.

  11. High-performance liquid chromatography-fluorescence assay of pyruvic acid to determine cysteine conjugate beta-lyase activity : application to S-1,2-dichlorovinyl-L-cysteine and S-2-benzothiazolyl-L-cysteine

    NARCIS (Netherlands)

    Stijntjes, G.J.; te Koppele, J.M.; Vermeulen, N P

    1992-01-01

    An HPLC-fluorescence assay has been developed for the determination of the activity of rat renal cytosolic cysteine conjugate beta-lyase. The method is based on isocratic HPLC separation and fluorescence detection of pyruvic acid, derivatized with o-phenylenediamine (OPD), and is shown to be rapid,

  12. Absorption and emission spectroscopic characterisation of a pyrene-flavin dyad

    International Nuclear Information System (INIS)

    Shirdel, J.; Penzkofer, A.; Prochazka, R.; Shen, Z.; Strauss, J.; Daub, J.

    2007-01-01

    The pyrene-flavin (isoalloxazine) dyad, PFD {C 44 H 31 N 5 O 5 ; CA Index name: 1-pyrenepropanoic acid, α-[[4,10-dihydro-2,4-dioxo-10- phenylbenzo[g]pteridin-3(2H)-yl)acetyl]amino]-, phenylmethyl ester (αR)-(9Cl); CA Registry number: 618907-57-6}, dissolved in either dichloromethane or acetonitrile is characterized by absorption and emission spectroscopy. Absorption cross-section spectra, stimulated emission cross-section spectra, fluorescence quantum distributions, quantum yields, and degrees of fluorescence polarisation are determined. The fluorescence decay after femtosecond pulse excitation is determined by fluorescence up-conversion. The ground-state absorption recovery is determined by picosecond pump and probe transmission measurements. The dye photo-stability is investigated by observation of absorption spectral changes due to prolonged blue-light excitation. The absorption spectrum of PFD dyad resembles the superposition of the absorption of isoalloxazine (flavin) and 1-methylpyrene. Long-wavelength photo-excitation of the flavin moiety causes fluorescence quenching by ground-state electron transfer from pyrene to isoalloxazine. Short-wavelength photo-excitation of the pyrene moiety causes (i) excited-state electron transfer from pyrene to isoalloxazine, and (ii) Foerster-type energy transfer from pyrene to flavin followed by ground-state electron transfer from pyrene to flavin.

  13. Fluorescent molecularly imprinted polymer thin films for specific protein detection prepared with dansyl ethylenediamine-conjugated O-acryloyl L-hydroxyproline.

    Science.gov (United States)

    Inoue, Yuki; Kuwahara, Atsushi; Ohmori, Kohei; Sunayama, Hirobumi; Ooya, Tooru; Takeuchi, Toshifumi

    2013-10-15

    Protein-imprinted polymers, capable of specific transduction of protein binding events into fluorescent signal change, were designed and synthesized by using dansyl ethylenediamine-conjugated O-acryloyl L-hydroxyproline (Hyp-En-Dans). Human serum albumin (HSA) was used as a model target protein and HSA-imprinted polymers (HSA-IP) were prepared on glass substrates. Specific fluorescence change was observed for HSA binding on the imprinted polymer thin film, whereas a weaker response was observed for other proteins, including bovine serum albumin, chymotrypsin, lysozyme, and avidin. The binding specificity was found to derive from the rigid structure of the hydrogen-bondable pyrrolidine moiety. Compared with SPR measurements, the non-specific binding caused by the polymer matrix and/or randomly located fluorescent monomer residues that did not compose specific binding sites did not contribute to the observed fluorescence change. These results revealed that the proposed protein-imprinting technique using Hyp-En-Dans could provide a highly selective protein-sensing platform, in which only specific binding events would be detected by fluorescent measurements. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Fluorescent CdSe/ZnS nanocrystal-peptide conjugates for long-term, nontoxic imaging and nuclear targeting in living cells

    International Nuclear Information System (INIS)

    Chen, Fanqing; Gerion, Daniele

    2004-01-01

    One of the biggest challenges in cell biology is the imaging of living cells. For this purpose, the most commonly used visualization tool is fluorescent markers. However, conventional labels, such as organic fluorescent dyes or green fluorescent proteins (GFP), lack the photostability to allow the tracking of cellular events that happen over minutes to days. In addition, they are either toxic to cells (dyes), or difficult to construct and manipulate (GFP). We report here the use of a new class of fluorescent labels, silanized CdSe/ZnS nanocrystal-peptide conjugates, for imaging the nuclei of living cells. CdSe/ZnS nanocrystals, or so called quantum dots (qdots), are extremely photostable, and have been used extensively in cellular imaging of fixed cells. However, most of the studies about living cells so far have been concerned only with particle entry into the cytoplasm or the localization of receptors on the cell membrane. Specific targeting of qdots to the nucleus of living cells ha s not been reported in previous studies, due to the lack of a targeting mechanism and proper particle size. Here we demonstrate for the first time the construction of a CdSe/ZnS nanocrystal-peptide conjugate that carries the SV40 large T antigen nuclear localization signal (NLS), and the transfection of the complex into living cells. By a novel adaptation of commonly used cell transfection techniques for qdots, we were able to introduce and retain the NLS-qdots conjugate in living cells for up to a week without detectable negative cellular effects. Moreover, we can visualize the movement of the CdSe/ZnS nanocrystal-peptide conjugates from cytoplasm to the nucleus, and the accumulation of the complex in the cell nucleus, over a long observation time period. This report opens the door for using qdots to visualize long-term biological events that happen in the cell nucleus, and provides a new nontoxic, long-term imaging platform for cell nuclear processes

  15. Vibrational Coupling in Conjugated π Systems with a view to Optimization of Fluorescence Yield through Phonon Confinement

    OpenAIRE

    O'Neill, Luke; Lynch, Patrick; McNamara, Mary; Byrne, Hugh J.

    2005-01-01

    A series of π conjugated systems were studied by absorption, photoluminescence and vibrational spectroscopy. As is common for these systems, a linear relationship between the positioning of the absorption and photoluminescence maxima plotted against inverse conjugation length is observed. The relationships are in good agreement with the simple particle in a box method, one of the earliest descriptions of the properties of one-dimensional organic molecules. In addition to the electronic transi...

  16. Cyanine 5.5 conjugated nanobubbles as a tumor selective contrast agent for dual ultrasound-fluorescence imaging in a mouse model.

    Directory of Open Access Journals (Sweden)

    Liyi Mai

    Full Text Available Nanobubbles and microbubbles are non-invasive ultrasound imaging contrast agents that may potentially enhance diagnosis of tumors. However, to date, both nanobubbles and microbubbles display poor in vivo tumor-selectivity over non-targeted organs such as liver. We report here cyanine 5.5 conjugated nanobubbles (cy5.5-nanobubbles of a biocompatible chitosan-vitamin C lipid system as a dual ultrasound-fluorescence contrast agent that achieved tumor-selective imaging in a mouse tumor model. Cy5.5-nanobubble suspension contained single bubble spheres and clusters of bubble spheres with the size ranging between 400-800 nm. In the in vivo mouse study, enhancement of ultrasound signals at tumor site was found to persist over 2 h while tumor-selective fluorescence emission was persistently observed over 24 h with intravenous injection of cy5.5-nanobubbles. In vitro cell study indicated that cy5.5-flurescence dye was able to accumulate in cancer cells due to the unique conjugated nanobubble structure. Further in vivo fluorescence study suggested that cy5.5-nanobubbles were mainly located at tumor site and in the bladder of mice. Subsequent analysis confirmed that accumulation of high fluorescence was present at the intact subcutaneous tumor site and in isolated tumor tissue but not in liver tissue post intravenous injection of cy5.5-nanobubbles. All these results led to the conclusion that cy5.5-nanobubbles with unique crosslinked chitosan-vitamin C lipid system have achieved tumor-selective imaging in vivo.

  17. Terbium(III)/gold nanocluster conjugates: the development of a novel ratiometric fluorescent probe for mercury(II) and a paper-based visual sensor.

    Science.gov (United States)

    Qi, Yan-Xia; Zhang, Min; Zhu, Anwei; Shi, Guoyue

    2015-08-21

    In this work, a novel ratiometric fluorescent probe was developed for rapid, highly accurate, sensitive and selective detection of mercury(II) (Hg(2+)) based on terbium(III)/gold nanocluster conjugates (Tb(3+)/BSA-AuNCs), in which bovine serum albumin capped gold nanoclusters (BSA-AuNCs) acted as the signal indicator and terbium(III) (Tb(3+)) was used as the build-in reference. Our proposed ratiometric fluorescent probe exhibited unique specificity toward Hg(2+) against other common environmentally and biologically important metal ions, and had high accuracy and sensitivity with a low detection limit of 1 nM. In addition, our proposed probe was effectively employed to detect Hg(2+) in the biological samples from the artificial Hg(2+)-infected rats. More significantly, an appealing paper-based visual sensor for Hg(2+) was designed by using filter paper embedded with Tb(3+)/BSA-AuNC conjugates, and we have further demonstrated its feasibility for facile fluorescent sensing of Hg(2+) in a visual format, in which only a handheld UV lamp is used. In the presence of Hg(2+), the paper-based visual sensor, illuminated by a handheld UV lamp, would undergo a distinct fluorescence color change from red to green, which can be readily observed with naked eyes even in trace Hg(2+) concentrations. The Tb(3+)/BSA-AuNC-derived paper-based visual sensor is cost-effective, portable, disposable and easy-to-use. This work unveiled a facile approach for accurate, sensitive and selective measuring of Hg(2+) with self-calibration.

  18. Determination of Conjugation Efficiency of Antibodies and Proteins to the Superparamagnetic Iron Oxide Nanoparticles by Capillary Electrophoresis with Laser-Induced Fluorescence Detection

    Energy Technology Data Exchange (ETDEWEB)

    Wang, F.-H.; Yoshitake, Takashi [Karolinska Institutet, Department of Neuroscience (Sweden); Kim, Do-Kyung; Muhammed, Mamoun [Royal Institute of Technology, Materials Chemistry Division (Sweden); Bjelke, Boerje [MRI-Center, Experimental Unit, Karolinska Institutet (Sweden); Kehr, Jan [Karolinska Institutet, Department of Neuroscience (Sweden)], E-mail: Jan.Kehr@neuro.ki.se

    2003-04-15

    The method based on capillary electrophoresis with laser-induced fluorescence detection (CE/LIF) was developed for determination of magnetic iron oxide nanoparticles (hydrodynamic diameters of 100 nm) functionalized with molecules containing primary amino groups. The magnetic nanoparticles with carboxylic or aminopropyl-trimethoxysilane groups at their surface were conjugated to the model proteins (bovine serum albumin, BSA; streptavidin or goat anti-rabbit immunoglobulin G, IgG) using carbodiimide as a zero-length cross-linker.The nanoparticle-protein conjugates (hydrodynamic diameter 163-194 nm) were derivatized with naphthalene-2,3-dicarboxaldehyde reagent and separated by CE/LIF with a helium-cadmium laser (excitation at 442 nm, emission at 488 nm). The separations were carried out by using a fused-silica capillary (effective length 48 cm, inner diameter 75 um) and 100 mM sodium borate buffer (pH 9.2), the potential was 30 kV. The detection limit for BSA-conjugate was 1.3 pg/10 nl, i.e. about 20 amol. The present method provides an efficient and fast tool for sensitive determination of the efficacy of biomolecular functionalization of magnetic nanoparticles. The CE/LIF technique requires only negligible sample volumes for analysis, which is especially suitable for controlling the process of preparation of functionalized nanoparticles with unique properties aimed to be used for diagnostic or therapeutic purposes.

  19. The effect of pyrene labelling on the thermal stability of actin filaments

    International Nuclear Information System (INIS)

    Halasi, Szulamit; Papp, Gabor; Bugyi, Beata; Barko, Szilvia; Orban, Jozsef; Ujfalusi, Zoltan; Visegrady, Balazs

    2006-01-01

    The ability of actin to form filaments is fundamental to its biological function and often characterised by various methods in vitro. One of the most frequently used methods capitalises on the observation that the fluorescence emission of a pyrene label on the Cys-374 residue of actin is enhanced by a factor of ∼20 during polymerisation. This method inherently involves the chemical modification of actin monomers with pyrene. It was reported earlier that the pyrene labelling of actin monomers has only small effect on the polymerisation and depolymerisation rates of actin, indicating that the method is suitable to characterise the effect of actin-binding proteins or peptides on the polymerisation kinetics. In our present work we tested the effect of the pyrene labelling on the thermal denaturation of actin filaments by using the method of differential scanning calorimetry (DSC). By recording the heat denaturation profiles of unlabelled and pyrene labelled actin filaments we observed that pyrene labelling shifted the melting point (T m ) of actin filaments from 66 to 68 deg. C. A similar effect was detected in the presence of equimolar concentration of phalloidin where the T m shifted from 79 to 82 deg. C. We concluded that the observed pyrene labelling induced differences of the thermal denaturation of actin filaments were small. The DSC results, therefore, confirmed that the methods based on the measurements of pyrene intensity during actin polymerisation are suitable to characterise the polymerisation kinetics of actin under in vitro conditions

  20. Graphene Oxide-terpyridine Conjugate: A Highly Selective Colorimetric and Sensitive Fluorescence Nano-chemosensor for Fe2+ in Aqueous Media

    Directory of Open Access Journals (Sweden)

    Bagher Eftekhari-Sis

    2016-07-01

    Full Text Available A graphene oxide-terpyridine conjugate (GOTC based colorimetric and fluorescent nano-chemosensor was synthesized. It showed high selectivity and sensitivity for Fe2+ and Fe3+ ions in neutral aqueous solution over other metal ions such as Li+, Na+, Ba2+, Ca2+, Al3+, Cd2+, Co2+, Cu2+, Hg2+, Mn2+, Ni2+, Pb2+, Zn2+, Cr3+ and Ag+. In absorption spectra, upon addition of Fe2+ or Fe3+, the sensor displayed a peak at 568 nm, by changing the color of the solution from light pink for GOTC to light magenta and deep magenta for Fe3+ and Fe2+, respectively. Also, the fluorescence studies revealed that, Fe2+, Fe3+ and Co2+ quench the emission of GOTC at 473 nm, while other metal ions do not quench the fluorescence of GOTC in solution. Colorimetric and fluorescence techniques could be used for detection of Fe2+ ion concentration at least about 6-10 μM in water solution. The sensing on test paper was also investigated for the naked-eye detection of Fe2+.

  1. A Conjugate of Pentamethine Cyanine and 18F as a Positron Emission Tomography/Near-Infrared Fluorescence Probe for Multimodality Tumor Imaging

    Directory of Open Access Journals (Sweden)

    Fei-Fei An

    2017-06-01

    Full Text Available The novel synthesis of a dual-modality, pentamethine cyanine (Cy5 fluorescent, 18F positron emission tomography (PET imaging probe is reported. The probe shows a large extinction coefficient and large quantum yield in the biologically transparent, near-infrared window (650–900 nm for in vivo fluorescent imaging. This fluorophore bears the isotope, 18F, giving a 18F-PET/near-infrared fluorescent (NIRF, bi-modal imaging probe, that combines the long-term stability of NIRF and the unlimited penetration depth of PET imaging. The bi-modal probe is labeled with 18F in a quick, one-step reaction, which is important in working with the rapid decay of 18F. The bi-modal probe bears a free carboxyl group, highlighting a PET/NIRF synthon that can be conjugated onto many advanced biomolecules for biomarker-specific in vivo dual-modal PET/NIR tumor imaging, confocal histology, and utility in multi-fluorophore, fluorescence-guided surgery. Its potential in vivo biocompatibility is explored in a quick proof-of-principal in vivo study. The dye is delivered to A549 xenograft flank-tumors to generate PET and NIRF signals at the tumor site. The tumor distribution is confirmed in ex vivo gamma counting and imaging. Pentamethine cyanine (Cy5 has the ability to preferentially accumulate in tumor xenografts. We substitute the PET/NIRF probe for Cy5, and explore this phenomenon.

  2. A new fluorescence/PET probe for targeting intracellular human telomerase reverse transcriptase (hTERT) using Tat peptide-conjugated IgM

    International Nuclear Information System (INIS)

    Jung, Kyung oh; Youn, Hyewon; Kim, Seung Hoo; Kim, Young-Hwa; Kang, Keon Wook; Chung, June-Key

    2016-01-01

    Despite an increasing need for methods to visualize intracellular proteins in vivo, the majority of antibody-based imaging methods available can only detect membrane proteins. The human telomerase reverse transcriptase (hTERT) is an intracellular target of great interest because of its high expression in several types of cancer. In this study, we developed a new probe for hTERT using the Tat peptide. An hTERT antibody (IgG or IgM) was conjugated with the Tat peptide, a fluorescence dye and "6"4Cu. HT29 (hTERT+) and U2OS (hTERT−) were used to visualize the intracellular hTERT. The hTERT was detected by RT-PCR and western blot. Fluorescence signals for hTERT were obtained by confocal microscopy, live cell imaging, and analyzed by Tissue-FAXS. In nude mice, tumors were visualized using the fluorescence imaging devices Maestro™ and PETBOX. In RT-PCR and western blot, the expression of hTERT was detected in HT29 cells, but not in U2OS cells. Fluorescence signals were clearly observed in HT29 cells and in U2OS cells after 1 h of treatment, but signals were only detected in HT29 cells after 24 h. Confocal microscopy showed that 9.65% of U2OS and 78.54% of HT29 cells had positive hTERT signals. 3D animation images showed that the probe could target intranuclear hTERT in the nucleus. In mice models, fluorescence and PET imaging showed that hTERT in HT29 tumors could be efficiently visualized. In summary, we developed a new method to visualize intracellular and intranuclear proteins both in vitro and in vivo. - Highlights: • We developed new probes for imaging hTERT using Tat-conjugated IgM antibodies labeled with a fluorescent dye and radioisotope. • This probes could be used to overcome limitation of conventional antibody imaging system in live cell imaging. • This system could be applicable to monitor intracellular and intranuclear proteins in vitro and in vivo.

  3. A new fluorescence/PET probe for targeting intracellular human telomerase reverse transcriptase (hTERT) using Tat peptide-conjugated IgM

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Kyung oh [Department of Nuclear Medicine, Seoul National University College of Medicine (Korea, Republic of); Biomedical Sciences, Seoul National University College of Medicine (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine (Korea, Republic of); Tumor Microenvironment Global Core Research Center, Seoul National University (Korea, Republic of); Youn, Hyewon, E-mail: hwyoun@snu.ac.kr [Department of Nuclear Medicine, Seoul National University College of Medicine (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine (Korea, Republic of); Tumor Microenvironment Global Core Research Center, Seoul National University (Korea, Republic of); Cancer Imaging Center, Seoul National University Hospital, Seoul (Korea, Republic of); Kim, Seung Hoo [Department of Nuclear Medicine, Seoul National University College of Medicine (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine (Korea, Republic of); Kim, Young-Hwa [Department of Nuclear Medicine, Seoul National University College of Medicine (Korea, Republic of); Biomedical Sciences, Seoul National University College of Medicine (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine (Korea, Republic of); Kang, Keon Wook [Department of Nuclear Medicine, Seoul National University College of Medicine (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine (Korea, Republic of); Chung, June-Key, E-mail: jkchung@snu.ac.kr [Department of Nuclear Medicine, Seoul National University College of Medicine (Korea, Republic of); Biomedical Sciences, Seoul National University College of Medicine (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine (Korea, Republic of); Tumor Microenvironment Global Core Research Center, Seoul National University (Korea, Republic of)

    2016-08-26

    Despite an increasing need for methods to visualize intracellular proteins in vivo, the majority of antibody-based imaging methods available can only detect membrane proteins. The human telomerase reverse transcriptase (hTERT) is an intracellular target of great interest because of its high expression in several types of cancer. In this study, we developed a new probe for hTERT using the Tat peptide. An hTERT antibody (IgG or IgM) was conjugated with the Tat peptide, a fluorescence dye and {sup 64}Cu. HT29 (hTERT+) and U2OS (hTERT−) were used to visualize the intracellular hTERT. The hTERT was detected by RT-PCR and western blot. Fluorescence signals for hTERT were obtained by confocal microscopy, live cell imaging, and analyzed by Tissue-FAXS. In nude mice, tumors were visualized using the fluorescence imaging devices Maestro™ and PETBOX. In RT-PCR and western blot, the expression of hTERT was detected in HT29 cells, but not in U2OS cells. Fluorescence signals were clearly observed in HT29 cells and in U2OS cells after 1 h of treatment, but signals were only detected in HT29 cells after 24 h. Confocal microscopy showed that 9.65% of U2OS and 78.54% of HT29 cells had positive hTERT signals. 3D animation images showed that the probe could target intranuclear hTERT in the nucleus. In mice models, fluorescence and PET imaging showed that hTERT in HT29 tumors could be efficiently visualized. In summary, we developed a new method to visualize intracellular and intranuclear proteins both in vitro and in vivo. - Highlights: • We developed new probes for imaging hTERT using Tat-conjugated IgM antibodies labeled with a fluorescent dye and radioisotope. • This probes could be used to overcome limitation of conventional antibody imaging system in live cell imaging. • This system could be applicable to monitor intracellular and intranuclear proteins in vitro and in vivo.

  4. Diethylenetriaminepentaacetic acid-gadolinium (DTPA-Gd)-conjugated polysuccinimide derivatives as magnetic resonance imaging contrast agents.

    Science.gov (United States)

    Lee, Ha Young; Jee, Hye Won; Seo, Sung Mi; Kwak, Byung Kook; Khang, Gilson; Cho, Sun Hang

    2006-01-01

    Biocompatible polysuccinimide (PSI) derivatives conjugated with diethylenetriaminepentaacetic acid gadolinium (DTPA-Gd) were prepared as magnetic resonance imaging (MRI) contrast agents. In this study, we synthesized PSI derivatives incorporating methoxy-poly(ethylene glycol) (mPEG) as hydrophilic ligand, hexadecylamine as hydrophobic ligand, and DTPA-Gd as contrast agent. PSI was synthesized by the polycondensation polymerization of aspartic acid. All the synthesized materials were characterized by proton nuclear magnetic resonance (1H NMR). Critical micellization concentrations were determined using fluorescent probes (pyrene). Micelle size and shape were measured by electro-photometer light scattering (ELS) and atomic force microscopy (AFM). The formed micelle size ranged from 100 to 300 nm. The T1-weighted MR images of the phantom prepared with PSI-mPEG-C16-(DTPA-Gd) were obtained in a 3.0 T clinical MR imager, and the conjugates showed a great potential as MRI contrast agents.

  5. Studies on the analysis of benzo(a)pyrene and its metabolites in biological samples by using high performance liquid chromatography/fluorescence detection and gas chromatography/mass spectrometry

    International Nuclear Information System (INIS)

    Lee, Won; Hong, Jee Eun; Shin, Hye Seung; Pyo, Hee Soo; Kim, Yun Je

    2003-01-01

    An analytical method the determination of benzo(a)pyrene (BaP) and its hydroxylated metabolites, 1-hydroxybenzo(a)pyrene (1-OHBaP), 3-hydroxybenzo(a)pyrene (3-OHBaP), benzo(a)pyrene-4,5-dihydrodial(4,5-diolBaP) and benzo(a)pyrene-7,8-dihydrodiol (7,8-diolBaP), in rat urine and plasma has been developed by HPLC/FLD and GC/MS. The derivatization with alkyl iodide was employed to improve the resolution and the detection of two mono hydroxylated metabolites, 1-OHBaP and 3-OHBaP, in LC and GC. BaP and its four metabolites in spiked urine were successfully separated by gradient elution on reverse phase ODS C 18 column (4.6 mm I.D., 100 mm length, particle size 5μm) using a binary mixture of MeOH/H 2 O (85/15, v/v) as mobile phase after ethylation at 90 .deg. C for 10 min. The extraction recoveries of BaP and its metabolites in spiked samples with liquid-liquid extraction, which was better than solid phase extraction, were in the range of 90.3-101.6% in n-hexane for urine and 95.7-106.3% in acetone for plasma, respectively. The calibration curves has shown good linearity with the correlation coefficients (R 2 ) varying from 0.992 to 1.000 for urine and from 0.996 to 1.000 for plasma, respectively. The detection limits of all analytes were obtained in the range of 0.01-0.1 ng/mL for urine and 0.1-0.4ng/mL for plasma, respectively. The metabolites of BaP were excreted as mono hydroxy and dihydrodiol forms after intraperitoneal infection of 20 mg/kg of BaP to rats. The total amounts of BaP and four metabolites excreted in dosed rat urine were 3.79 ng over the 0 - 96 hr period from administration and the excretional recovery was less than 0.065% of the injection amounts of BaP. The proposed method was successfully applied to the determination of BaP and its hydroxylated metabolites in rat urine and plasma for the pharmacokinetic studies

  6. Preparation of dual-responsive hybrid fluorescent nano probe based on graphene oxide and boronic acid/BODIPY-conjugated polymer for cell imaging

    Energy Technology Data Exchange (ETDEWEB)

    Khoerunnisa [Department of IT Convergence, Korea National University of Transportation, Chungju 380–702 (Korea, Republic of); Kang, Eun Bi [Department of Chemical and Biological Engineering, Korea National University of Transportation, Chungju 380–702 (Korea, Republic of); Mazrad, Zihnil Adha Islamy [Department of IT Convergence, Korea National University of Transportation, Chungju 380–702 (Korea, Republic of); Lee, Gibaek [Department of Chemical and Biological Engineering, Korea National University of Transportation, Chungju 380–702 (Korea, Republic of); In, Insik [Department of IT Convergence, Korea National University of Transportation, Chungju 380–702 (Korea, Republic of); Department of Polymer Science and Engineering, Korea National University of Transportation, Chungju 380–702 (Korea, Republic of); Park, Sung Young, E-mail: parkchem@ut.ac.kr [Department of IT Convergence, Korea National University of Transportation, Chungju 380–702 (Korea, Republic of); Department of Chemical and Biological Engineering, Korea National University of Transportation, Chungju 380–702 (Korea, Republic of)

    2017-02-01

    Here, we report a pH- and thermo-responsive fluorescent nanomaterial of functionalized reduced graphene oxide (rGO) with cross-linked polymer produced via catechol-boronate diol binding mechanism. When conjugated with the hydrophobic dye boron dipyrromethane (BODIPY), this material can act as a dual-responsive nanoplatform for cells imaging. 2-Chloro-3′,4′-dihydroxyacetophenone (CCDP)-quaternized-poly(dimethylaminoethyl methacrylate-co-N-isopropylacrylamide) [C-PDN] was cross-linked with BODIPY and 4-chlorophenyl boronic acid (BA)-quaternized-poly(ethylene glycol)-g-poly(dimethylaminoethyl methacrylate-co-N-isopropylacrylamide) [BB-PPDN]. The GO was then reduced by the catechol group in the cross-linked polymer to synthesize rGO nanoparticles, which able to stabilize the quenching mechanism. This nanoplatform exhibits intense fluorescence at acidic pH and low fluorescence at physiological pH. Confocal laser scanning microscopy (CLSM) images shows bright fluorescence at lysosomal pH and total quench at physiological pH. Therefore, we have successfully developed a promising sensitive bio-imaging probe for identifying cancer cells. - Graphical abstract: [BB-PPDN]-[C-PDN]/rGO nanoparticles with boronic acid-catechol cis-diol binding mechanism toward change in pH demonstrated good biocompatibility and effective quenching for cancer cell detection. - Highlights: • Dual responsive (pH- and thermo) fluorescent nano probe was proposed for cells imaging. • The mechanism was based on cis-diol binding mechanism of boronic acid and catechol. • Reduced graphene oxide was used as quencher on nano-platform. • Detection was controlled dependent on pH based on diol compound of boron chemistry.

  7. The application of pH-sensitive fluorescent dyes in lactic acid bacteria reveals distinct extrusion systems for unmodified and conjugated dyes.

    Science.gov (United States)

    Glaasker, E; Konings, W N; Poolman, B

    1996-01-01

    Intracellular pH in bacteria can be measured efficiently between internal pH values of 6.5 and 8.5 with the fluorescent pH indicator 2',7'-bis-(2-carboxyethyl)-5[and-6]-carboxyfluorescein (BCECF). A new fluorescent pH probe with a lower pKa(app) than BCECF was synthesized from fluorescein isothiocyanate and glutamate. The new probe, N-(fluorescein thio-ureanyl)-glutamate (FTUG), was much less sensitive to changes in concentrations of KCl than was BCECF. Similar to BCECF, an efflux of FTUG independent of the proton motive force, but dependent on ATP, was observed both in Lactobacillus plantarum and Lactococcus lactis. Corrections for probe efflux allowed accurate measurements of the pHin. Similar intracellular pH values were determined with FTUG and BCECF, in the range where both probes can be applied, and the pH values correlated well with those estimated from the distribution of radio-labelled benzoic acid. Since FITC can easily be coupled to substrates containing an amino group, it is possible to develop other FITC derivatives as well. The mechanisms of probe excretion and the nature of the excreted product(s) were studied in further detail for BCECF and FTUG. BCECF was excreted from wild-type L. lactis in an unmodified form as was determined by chromatographic and mass spectrometry analysis. In the case of FTUG, the excreted product was a conjugated derivative. Unmodified FTUG was not excreted, although it was present in cellular extracts from L. lactis. Exit of BCECF was completely inhibited in a BCECF efflux mutant (Bef-) of L. lactis, whereas FTUG-conjugate efflux in this mutant was similar to the wild-type. Addition of indomethacin, a known inhibitor of BCECF efflux in human epithelial cells, resulted in complete inhibition of BCECF efflux in wild-type L. lactis, whereas FTUG-conjugate exit was only slightly affected. The results of the mutant and inhibitor studies suggest that FTUG-conjugate and BCECF efflux in L. lactis are mediated by different ATP

  8. Tween 20-stabilized gold nanoparticles combined with adenosine triphosphate-BODIPY conjugates for the fluorescence detection of adenosine with more than 1000-fold selectivity

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Szu-Ying; Shih, Ya-Chen [Department of Chemistry, National Sun Yat-sen University, Taiwan (China); Tseng, Wei-Lung, E-mail: tsengwl@mail.nsysu.edu.tw [Department of Chemistry, National Sun Yat-sen University, Taiwan (China); School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Taiwan (China); Center for Nanoscience and Nanotechnology, National Sun Yat-sen University, Taiwan (China); Center for Stem Cell Research, Kaohsiung Medical University, Taiwan (China)

    2015-02-01

    Graphical abstract: A simple, enzyme-free, label-free, sensitive and selective system was developed for detecting adenosine based on the use of Tween 20-stabilized gold nanoparticles as an efficient quencher for boron dipyrromethene-conjugated adenosine 5′-triphosphate and as a recognition element for adenosine. - Highlights: • The proposed method can detect adenosine with more than 1000-fold selectivity. • The analysis of adenosine is rapid (∼6 min) using the proposed method. • This method provided better sensitivity for adenosine as compared to aptamer-based sensors. • This method can be applied for the determination of adenosine in urine. - Abstract: This study describes the development of a simple, enzyme-free, label-free, sensitive, and selective system for detecting adenosine based on the use of Tween 20-stabilized gold nanoparticles (Tween 20-AuNPs) as an efficient fluorescence quencher for boron dipyrromethene-conjugated adenosine 5′-triphosphate (BODIPY-ATP) and as a recognition element for adenosine. BODIPY-ATP can interact with Tween 20-AuNPs through the coordination between the adenine group of BODIPY-ATP and Au atoms on the NP surface, thereby causing the fluorescence quenching of BODIPY-ATP through the nanometal surface energy transfer (NSET) effect. When adenosine attaches to the NP surface, the attached adenosine exhibits additional electrostatic attraction to BODIPY-ATP. As a result, the presence of adenosine enhances the efficiency of AuNPs in fluorescence quenching of BODIPY-ATP. The AuNP-induced fluorescence quenching of BODIPY-ATP progressively increased with an increase in the concentration of adenosine; the detection limit at a signal-to-noise ratio of 3 for adenosine was determined to be 60 nM. The selectivity of the proposed system was more than 1000-fold for adenosine over any adenosine analogs and other nucleotides. The proposed system combined with a phenylboronic acid-containing column was successfully applied to the

  9. Tween 20-stabilized gold nanoparticles combined with adenosine triphosphate-BODIPY conjugates for the fluorescence detection of adenosine with more than 1000-fold selectivity

    International Nuclear Information System (INIS)

    Hung, Szu-Ying; Shih, Ya-Chen; Tseng, Wei-Lung

    2015-01-01

    Graphical abstract: A simple, enzyme-free, label-free, sensitive and selective system was developed for detecting adenosine based on the use of Tween 20-stabilized gold nanoparticles as an efficient quencher for boron dipyrromethene-conjugated adenosine 5′-triphosphate and as a recognition element for adenosine. - Highlights: • The proposed method can detect adenosine with more than 1000-fold selectivity. • The analysis of adenosine is rapid (∼6 min) using the proposed method. • This method provided better sensitivity for adenosine as compared to aptamer-based sensors. • This method can be applied for the determination of adenosine in urine. - Abstract: This study describes the development of a simple, enzyme-free, label-free, sensitive, and selective system for detecting adenosine based on the use of Tween 20-stabilized gold nanoparticles (Tween 20-AuNPs) as an efficient fluorescence quencher for boron dipyrromethene-conjugated adenosine 5′-triphosphate (BODIPY-ATP) and as a recognition element for adenosine. BODIPY-ATP can interact with Tween 20-AuNPs through the coordination between the adenine group of BODIPY-ATP and Au atoms on the NP surface, thereby causing the fluorescence quenching of BODIPY-ATP through the nanometal surface energy transfer (NSET) effect. When adenosine attaches to the NP surface, the attached adenosine exhibits additional electrostatic attraction to BODIPY-ATP. As a result, the presence of adenosine enhances the efficiency of AuNPs in fluorescence quenching of BODIPY-ATP. The AuNP-induced fluorescence quenching of BODIPY-ATP progressively increased with an increase in the concentration of adenosine; the detection limit at a signal-to-noise ratio of 3 for adenosine was determined to be 60 nM. The selectivity of the proposed system was more than 1000-fold for adenosine over any adenosine analogs and other nucleotides. The proposed system combined with a phenylboronic acid-containing column was successfully applied to the

  10. Comparison of a chimeric anti-carcinoembryonic antigen antibody conjugated with visible or near-infrared fluorescent dyes for imaging pancreatic cancer in orthotopic nude mouse models

    Science.gov (United States)

    Maawy, Ali A.; Hiroshima, Yukihiko; Kaushal, Sharmeela; Luiken, George A.; Hoffman, Robert M.; Bouvet, Michael

    2013-12-01

    The aim of this study was to evaluate a set of visible and near-infrared dyes conjugated to a tumor-specific chimeric antibody for high-resolution tumor imaging in orthotopic models of pancreatic cancer. BxPC-3 human pancreatic cancer was orthotopically implanted into pancreata of nude mice. Mice received a single intravenous injection of a chimeric anti-carcinoembryonic antigen antibody conjugated to one of the following fluorophores: 488-nm group (Alexa Fluor 488 or DyLight 488); 550-nm group (Alexa Fluor 555 or DyLight 550); 650-nm group (Alexa Fluor 660 or DyLight 650), or the 750-nm group (Alexa Fluor 750 or DyLight 755). After 24 h, the Olympus OV100 small-animal imaging system was used for noninvasive and intravital fluorescence imaging of mice. Dyes were compared with respect to depth of imaging, resolution, tumor-to-background ratio (TBR), photobleaching, and hemoglobin quenching. The longer wavelength dyes had increased depth of penetration and ability to detect the smallest tumor deposits and provided the highest TBRs, resistance to hemoglobin quenching, and specificity. The shorter wavelength dyes were more photostable. This study showed unique advantages of each dye for specific cancer imaging in a clinically relevant orthotopic model.

  11. Preliminary study on the inhibition of nuclear internalization of Tat peptides by conjugation with a receptor-specific peptide and fluorescent dyes

    Science.gov (United States)

    Shen, Duanwen; Liang, Kexiang; Ye, Yunpeng; Tetteh, Elizabeth; Achilefu, Samuel

    2006-02-01

    Numerous studies have shown that basic Tat peptide (48-57) internalized non-specifically in cells and localized in the nucleus. However, localization of imaging agents in cellular nucleus is not desirable because of the potential mutagenesis. When conjugated to the peptides that undergo receptor-mediated endocytosis, Tat peptide could target specific cells or pathologic tissue. We tested this hypothesis by incorporating a somatostatin receptor-avid peptide (octreotate, Oct) and two different fluorescent dyes, Cypate 2 (Cy2) and fluorescein 5'-carboxlic acid (5-FAM), into the Tat-peptide sequence. In addition to the Cy2 or 5-FAM-labeled Oct conjugated to Tat peptide (Tat) to produce Tat-Oct-Cypate2 or Tat-Oct-5-FAM, we also labeled the Tat the Tat peptide with these dyes (Tat-Cy2 and Tat-5-FAM) to serve as positive control. A somatostatin receptor-positive pancreatic tumor cell line, AR42J, was used to assess cell internalization. The results show that Tat-5-FAM and Tat-Cypate2 localized in both nucleus and cytoplasm of the cells. In contrast to Tat-Oct-Cypate2, which localized in both the cytoplasm and nucleus, Tat-Oct-5-FAM internalized in the cytoplasm but not in the nucleus of AR42J cells. The internalizations were inhibited by adding non-labeled corresponding peptides, suggesting that the endocytoses of each group of labeled and the corresponding unlabeled compounds occurred through a common pathway. Thus, fluorescent probes and endocytosis complex between octreotate and somatostatin receptors in cytoplasm could control nuclear internalization of Tat peptides.

  12. Flow cytometric measurement of the metabolism of benzo [a] pyrene by mouse liver cells in culture

    International Nuclear Information System (INIS)

    Bartholomew, J.C.; Wade, C.G.; Dougherty, K.

    1984-01-01

    The metabolism of benzo[a]pyrene in individual cells was monitored by flow cytometry. The measurements are based on the alterations that occur in the fluorescence emission spectrum of benzo[a]pyrene when it is converted to various metabolities. Using present instrumentation the technique could easily detect 1 x 10/sup 6/ molecules per cells of benzo [a]pyrene and 1 x 10/sup 7/ molecules per cell of the diol epoxide. The analysis of C3H IOT 1/2 mouse fibroblasts growing in culture indicated that there was heterogeneity in the conversion of the parent compound into diol epoxide derivative suggesting that some variation in sensitivity to transformation by benzo[a]pyrene may be due to differences in cellular metabolism

  13. Fluorescence polarization measures energy funneling in single light-harvesting antennas--LH2 vs conjugated polymers.

    Science.gov (United States)

    Camacho, Rafael; Tubasum, Sumera; Southall, June; Cogdell, Richard J; Sforazzini, Giuseppe; Anderson, Harry L; Pullerits, Tõnu; Scheblykin, Ivan G

    2015-10-19

    Numerous approaches have been proposed to mimic natural photosynthesis using artificial antenna systems, such as conjugated polymers (CPs), dendrimers, and J-aggregates. As a result, there is a need to characterize and compare the excitation energy transfer (EET) properties of various natural and artificial antennas. Here we experimentally show that EET in single antennas can be characterized by 2D polarization imaging using the single funnel approximation. This methodology addresses the ability of an individual antenna to transfer its absorbed energy towards a single pool of emissive states, using a single parameter called energy funneling efficiency (ε). We studied individual peripheral antennas of purple bacteria (LH2) and single CP chains of 20 nm length. As expected from a perfect antenna, LH2s showed funneling efficiencies close to unity. In contrast, CPs showed lower average funneling efficiencies, greatly varying from molecule to molecule. Cyclodextrin insulation of the conjugated backbone improves EET, increasing the fraction of CPs possessing ε = 1. Comparison between LH2s and CPs shows the importance of the protection systems and the protein scaffold of LH2, which keep the chromophores in functional form and at such geometrical arrangement that ensures excellent EET.

  14. Fluorescence polarization measures energy funneling in single light-harvesting antennas—LH2 vs conjugated polymers

    Science.gov (United States)

    Camacho, Rafael; Tubasum, Sumera; Southall, June; Cogdell, Richard J.; Sforazzini, Giuseppe; Anderson, Harry L.; Pullerits, Tõnu; Scheblykin, Ivan G.

    2015-10-01

    Numerous approaches have been proposed to mimic natural photosynthesis using artificial antenna systems, such as conjugated polymers (CPs), dendrimers, and J-aggregates. As a result, there is a need to characterize and compare the excitation energy transfer (EET) properties of various natural and artificial antennas. Here we experimentally show that EET in single antennas can be characterized by 2D polarization imaging using the single funnel approximation. This methodology addresses the ability of an individual antenna to transfer its absorbed energy towards a single pool of emissive states, using a single parameter called energy funneling efficiency (ɛ). We studied individual peripheral antennas of purple bacteria (LH2) and single CP chains of 20 nm length. As expected from a perfect antenna, LH2s showed funneling efficiencies close to unity. In contrast, CPs showed lower average funneling efficiencies, greatly varying from molecule to molecule. Cyclodextrin insulation of the conjugated backbone improves EET, increasing the fraction of CPs possessing ɛ = 1. Comparison between LH2s and CPs shows the importance of the protection systems and the protein scaffold of LH2, which keep the chromophores in functional form and at such geometrical arrangement that ensures excellent EET.

  15. Fluorescent Dansyl-Guanosine Conjugates that Bind c-MYC Promoter G-Quadruplex and Downregulate c-MYC Expression.

    Science.gov (United States)

    Pavan Kumar, Y; Saha, Puja; Saha, Dhurjhoti; Bessi, Irene; Schwalbe, Harald; Chowdhury, Shantanu; Dash, Jyotirmayee

    2016-03-02

    The four-stranded G-quadruplex present in the c-MYC P1 promoter has been shown to play a pivotal role in the regulation of c-MYC transcription. Small-molecule compounds capable of inhibiting the c-MYC promoter activity by stabilising the c-MYC G-quadruplex could potentially be used as anticancer agents. In this context, here we report the synthesis of dansyl-guanosine conjugates through one-pot modular click reactions. The dansyl-guanosine conjugates can selectively detect c-MYC G-quadruplex over other biologically relevant quadruplexes and duplex DNA and can be useful as staining reagents for selective visualisation of c-MYC G-quadruplex over duplex DNA by gel electrophoresis. NMR spectroscopic titrations revealed the preferential binding sites of these dansyl ligands to the c-MYC G-quadruplex. A dual luciferase assay and qRT-PCR revealed that a dansyl-bisguanosine ligand represses the c-MYC expression, possibly by stabilising the c-MYC G-quadruplex. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Phenylethynylpyrene excimer forming hybridization probes for fluorescence SNP detection

    DEFF Research Database (Denmark)

    Prokhorenko, Igor A.; Astakhova, Irina V.; Momynaliev, Kuvat T.

    2009-01-01

    Excimer formation is a unique feature of some fluorescent dyes (e.g., pyrene) which can be used for probing the proximity of biomolecules. Pyrene excimer fluorescence has previously been used for homogeneous detection of single nucleotide polymorphism (SNP) on DNA. 1-Phenylethynylpyrene (1-1-PEPy...

  17. CA 19-9 Pancreatic Tumor Marker Fluorescence Immunosensing Detection via Immobilized Carbon Quantum Dots Conjugated Gold Nanocomposite.

    Science.gov (United States)

    Alarfaj, Nawal Ahmad; El-Tohamy, Maha Farouk; Oraby, Hesham Farouk

    2018-04-11

    The clinical detection of carbohydrate antigen 19-9 (CA 19-9), a tumor marker in biological samples, improves and facilitates the rapid screening and diagnosis of pancreatic cancer. A simple, low cost, fast, and green synthesis method to prepare a viable carbon quantum dots/gold (CQDs/Au) nanocomposite fluorescence immunosensing solution for the detection of CA 19-9 was reported. The present method is conducted by preparing glucose-derived CQDs using a microwave-assisted method. CQDs were employed as reducing and stabilizing agents for the preparation of a CQDs/Au nanocomposite. The immobilized anti-CA 19-9-labeled horseradish peroxidase enzyme (Ab-HRP) was anchored to the surface of a CQDs/Au nanocomposite by a peptide interaction between the carboxylic and amine active groups. The CA 19-9 antigen was trapped by another monoclonal antibody that was coated on the surface of microtiter wells. The formed sandwich capping antibody-antigen-antibody enzyme complex had tunable fluorescence properties that were detected under excitation and emission wavelengths of 420 and 530 nm. The increase in fluorescence intensities of the immunoassay sensing solution was proportional to the CA 19-9 antigen concentration in the linear range of 0.01-350 U mL -1 and had a lower detection limit of 0.007 U mL -1 . The proposed CQDs/Au nanocomposite immunoassay method provides a promising tool for detecting CA 19-9 in human serum.

  18. Rapid genotyping using pyrene-perylene locked nucleic acid complexes

    DEFF Research Database (Denmark)

    Kumar, Santhosh T.; Myznikova, Anna; Samokhina, Evgeniya

    2013-01-01

    We have developed an assay for single strand DNA and RNA detection which is based on novel pyrene-perylene FRET pairs attached to short LNA/DNA probes. The assay is based on ratiometric emission upon binding of target DNA/RNA by three combinations of fluorescent LNA/DNA reporter strands. Specific...... geometry of the pyrene fluorophore attached to the 2'-amino group of 2'-amino-LNA in position 4 allows for the first time to efficiently utilize dipole-dipole orientation parameter for sensing of single-nucleotide polymorphisms (SNPs) in nucleic acid targets by FRET. Using novel probes, SNP detection......-perylene FRET pairs, e.g., in imaging and clinical diagnostics....

  19. Pyrene–nucleobase conjugates: synthesis, oligonucleotide binding and confocal bioimaging studies

    Directory of Open Access Journals (Sweden)

    Artur Jabłoński

    2017-11-01

    Full Text Available Fluorescent pyrene–linker–nucleobase (nucleobase = thymine, adenine conjugates with carbonyl and hydroxy functionalities in the linker were synthesized and characterized. X-ray single-crystal structure analysis performed for the pyrene–C(OCH2CH2–thymine (2 conjugate reveals dimers of molecules 2 stabilized by hydrogen bonds between the thymine moieties. The photochemical characterization showed structure-dependent fluorescence properties of the investigated compounds. The conjugates bearing a carbonyl function represent weak emitters as compared to compounds with a hydroxy function in the linker. The self-assembly properties of pyrene nucleobases were investigated in respect to their binding to single and double strand oligonucleotides in water and in buffer solution. In respect to the complementary oligothymidine T10 template in water, compounds 3 and 5 both show a self-assembling behavior according to canonical base–base pairing. However, in buffer solution, derivative 5 was much more effective than 3 in binding to the T10 template. Furthermore the adenine derivative 5 binds to the double-stranded (dA10–T10 template with a self-assembly ratio of 112%. Such a high value of a self-assembly ratio can be rationalized by a triple-helix-like binding, intercalation, or a mixture of both. Remarkably, compound 5 also shows dual staining pattern in living HeLa cells. Confocal microscopy confirmed that 5 predominantly stains mitochondria but it also accumulates in the nucleoli of the cells.

  20. RGDS-conjugated CdSeTe/CdS quantum dots as near-infrared fluorescent probe: preparation, characterization and bioapplication

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhenzhen; Zhang, Qiyi; Huang, Huaying; Ren, Changjing; Pan, Yujin; Wang, Qing; Zhao, Qiang, E-mail: Zhaoqiang@scu.edu.cn [Sichuan University, School of Chemical Engineering (China)

    2016-12-15

    In the experiments, high-quality, water-soluble and near-infrared (NIR)-emitting CdSeTe and CdSeTe/CdS quantum dots (QDs) were successfully prepared. The average size of CdSeTe⁄CdS QDs was 7.68 nm and CdSeTe QDs was 4.33 nm. Arginine-glycine-aspartic-serine acid (RGDS) peptides were linked to CdSeTe/CdS QDs by N-(3-(dimethylamino)propyl)-N′-ehtylcarbodiimide hydrochloride (EDC) and N′-hydroxysuccinimide (NHS). The prepared RGDS-tagged NIR CdSeTe/CdS QDs (denoted as RGDS-CdSeTe/CdS) had an average diameter of 24.83 nm and were used for cancer cell immunofluorescence imaging. The characteristics of RGDS-conjugated CdSeTe/CdS such as morphology, structure, spectra, stability, cytotoxicity, and near-infrared microscopic imaging were investigated in detail. HepG2 cells were incubated with the novel fluorescent probe (RGDS-CdSeTe/CdS), which realized immunofluorescence targeting and imaging. The results reported here open up new perspectives for integrin-targeted near-infrared imaging and may aid in tumor detection including imaging-guided surgery.

  1. Cy5.5 conjugated MnO nanoparticles for magnetic resonance/near-infrared fluorescence dual-modal imaging of brain gliomas.

    Science.gov (United States)

    Chen, Ning; Shao, Chen; Li, Shuai; Wang, Zihao; Qu, Yanming; Gu, Wei; Yu, Chunjiang; Ye, Ling

    2015-11-01

    The fusion of molecular and anatomical modalities facilitates more reliable and accurate detection of tumors. Herein, we prepared the PEG-Cy5.5 conjugated MnO nanoparticles (MnO-PEG-Cy5.5 NPs) with magnetic resonance (MR) and near-infrared fluorescence (NIRF) imaging modalities. The applicability of MnO-PEG-Cy5.5 NPs as a dual-modal (MR/NIRF) imaging nanoprobe for the detection of brain gliomas was investigated. In vivo MR contrast enhancement of the MnO-PEG-Cy5.5 nanoprobe in the tumor region was demonstrated. Meanwhile, whole-body NIRF imaging of glioma bearing nude mouse exhibited distinct tumor localization upon injection of MnO-PEG-Cy5.5 NPs. Moreover, ex vivo CLSM imaging of the brain slice hosting glioma indicated the preferential accumulation of MnO-PEG-Cy5.5 NPs in the glioma region. Our results therefore demonstrated the potential of MnO-PEG-Cy5.5 NPs as a dual-modal (MR/NIRF) imaging nanoprobe in improving the diagnostic efficacy by simultaneously providing anatomical information from deep inside the body and more sensitive information at the cellular level. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Conformational studies of the (+)-trans, (-)-trans, (+)-cis, and (-)-cis adducts of anti-benzo[a]pyrene diolepoxide to N2-dG in duplex oligonucleotides using polyacrylamide gel electrophoresis and low-temperature fluorescence spectroscopy

    NARCIS (Netherlands)

    Suh, Myungkoo; Ariese, Freek; Small, Gerald J.; Jankowiak, Ryszard; Liu, Tong Ming; Geacintov, Nicholas E.

    1995-01-01

    Using polyacrylamide gel electrophoresis (PAGE) and low-temperature, laser-induced fluorescence line narrowing (FLN) and non-line narrowing (NLN) spectroscopic methods, the conformational characteristics of stereochemically defined and site-specific adducts derived from the binding of

  3. Excimer fluorescence of liquid crystalline systems

    Science.gov (United States)

    Sakhno, Tamara V.; Khakhel, Oleg A.; Barashkov, Nikolay N.; Korotkova, Irina V.

    1996-04-01

    The method of synchronous scanning fluorescence spectroscopy shows a presence of dimers of pyrene in a polymeric matrix. The results suggest that excimer formation takes place with dimers in liquid crystalline systems.

  4. Synthesis and Characterization of Novel Polythiophenes Containing Pyrene Chromophores: Thermal, Optical and Electrochemical Properties

    Directory of Open Access Journals (Sweden)

    Bianca X. Valderrama-García

    2016-01-01

    Full Text Available A novel series of pyrene containing thiophene monomers TPM1–5 were synthesized and fully characterized by FTIR, MS, 1H- and 13C-NMR spectroscopy; their thermal properties were determined by TGA and DSC. These monomers were chemically polymerized using FeCl3 as oxidizing agent to give the corresponding oligomers TPO1–5 and they were electrochemically polymerized to obtain the corresponding polymer films deposited onto ITO. All oligomers exhibited good thermal stability, with T10 values between 255 and 299 °C, and Tg values varying from 36 to 39 °C. The monomers showed an absorption band at 345 nm due to the S0 → S2 transition of the pyrene group, whereas the fluorescence spectra showed a broad emission band arising from the “monomer” emission at 375–420 nm. The obtained polymers exhibited two absorption bands at 244 and 354 nm, due to the polythiophene and the pyrene moieties, respectively. The fluorescence spectra of polymers showed a broad “monomer” emission at 380–420 nm followed by an intense excimer emission band at 570 nm, due to the presence of intramolecular pyrene-pyrene interactions in these compounds.

  5. Novel asymmetrical pyrene derivatives as light emitting materials: Synthesis and photophysics

    International Nuclear Information System (INIS)

    Li Yang; Wang Dong; Wang Lei; Li Zhengqiang; Cui Qing; Zhang Haiquan; Yang Huai

    2012-01-01

    A series of novel substituted pyrene derivatives with asymmetrical groups have been successfully synthesized in excellent yield. Structures of the asymmetrical compound were fully characterized by 1 H-NMR, IR spectroscopy and mass spectrometry. By introducing ethynyl functions to pyrene, we obtained highly efficient blue and green light emitting materials. It has been demonstrated that the emission characteristics of pyrene derivatives have been bathochromatically tuned in the visible region by extending the π-conjugation. The photophysical properties of these compounds were carefully examined in different organic solvents and different concentrations. The electrochemical properties and geometrical electronic structures of the new pyrene derivatives have been investigated by cyclic voltammograms and density functional theory (DFT) calculations. - Highlights: ► It is the first research about asymmetrial pyrene derivatives as highly efficient light emitting materials. ► The solvatochromism and concentration effect of the new compounds have been discussed. ► Furthermore, the electrochemical properties and geometrical electronic structures were also investigated in this paper.

  6. Pyrene appended bile acid conjugates: Synthesis and a structure ...

    Indian Academy of Sciences (India)

    A wide variety of novel compounds obtained by combining two types of known organogelators, ... Additionally, the gelation properties can be fine-tuned by inserting different functional .... a QUANTA 200 scanning electron microscope with a.

  7. Pyrene degradation by yeasts and filamentous fungi.

    Science.gov (United States)

    Romero, M Cristina; Salvioli, Mónica L; Cazau, M Cecilia; Arambarri, A M

    2002-01-01

    The saprotrophic soil fungi Fusarium solani (Mart.) Sacc., Cylindrocarpon didymum (Hartig) Wollenw, Penicillium variabile Sopp. and the yeasts Rhodotorula glutinis (Fresenius) Harrison and Rhodotorula minuta (Saito) Harrison were cultured in mineral medium with pyrene. The remaining pyrene concentrations were periodically determined during 20 incubation days, using HPLC. To assess the metabolism of pyrene degradation we added 0.1 microCi of [4,5,9,10] 14C-pyrene to each fungi culture and measured the radioactivity in the volatile organic substances, extractable, aqueous phase, biomass and 14CO2 fractions. The assays demonstrated that F. solani and R. glutinis metabolized pyrene as a sole source of carbon. Differences in their activities at the beginning of the cultures disappeared by the end of the experiment, when 32 and 37% of the original pyrene concentration was detected, for the soil fungi and yeasts, respectively. Among the filamentous fungi, F. solani was highly active and oxidized pyrene; moreover, small but significant degradation rates were observed in C. didymum and P. variahile cultures. An increase in the 14CO2 evolution was observed at the 17th day with cosubstrate. R. glutinis and R. minuta cultures showed similar ability to biotransform pyrene, and that 35% of the initial concentration was consumed at the end of the assay. The same results were obtained in the experiments with or without glucose as cosubstrate.

  8. Detection of Salmonella typhi utilizing bioconjugated fluorescent polymeric nanoparticles

    International Nuclear Information System (INIS)

    Jain, Swati; Chattopadhyay, Sruti; Jackeray, Richa; Abid, Zainul; Singh, Harpal

    2016-01-01

    Present work demonstrates effective utilization of functionalized polymeric fluorescent nanoparticles as biosensing probe for the detection of Salmonella typhi bacteria on modified polycarbonate (PC) filters in about 3 h. Antibody modified-PC membranes were incubated with contaminated bacterial water for selective capturing which were detected by synthesized novel bioconjugate probe. Core–shell architecture of polymeric nanoparticles endows them with aqueous stabilization and keto-enolic functionalities making them usable for covalently linking S. typhi antibodies without any crosslinker or activator. Bradford analysis revealed that one nanoparticle has an average of 3.51 × 10"−"1"9 g or 21 × 10"4 bound S. typhi Ab molecules. Analysis of the regions of interest (ROI) in fluorescent micrographs of modified fluoroimmunoassay showed higher detection sensitivity of 5 × 10"2 cells/mL due to signal amplification unlike conventional naked dye FITC-Ab conjugate. Fluorescence of pyrene dye remained same on immobilization of biomolecules and nanoparticles showed stable fluorescent intensity under prolong exposure to laser owing to protective polymeric layer allowing accurate identification of bacteria. Surface-functionalized PC matrix and fluorescent label NPs permit covalent interactions among biomolecules enhancing signal acquisitions showing higher detection efficiency as compared to conventional microtiter plate-based system. Our novel immunoassay has the potential to be explored as rapid detection method for identifying S. typhi contaminations in water.Graphical Abstract

  9. Detection of Salmonella typhi utilizing bioconjugated fluorescent polymeric nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Swati, E-mail: swatijain.iitd@gmail.com; Chattopadhyay, Sruti, E-mail: sruticiitd@gmail.com; Jackeray, Richa; Abid, Zainul; Singh, Harpal, E-mail: harpal2000@yahoo.com [Centre for Biomedical Engineering, Indian Institute of Technology-Delhi (India)

    2016-05-15

    Present work demonstrates effective utilization of functionalized polymeric fluorescent nanoparticles as biosensing probe for the detection of Salmonella typhi bacteria on modified polycarbonate (PC) filters in about 3 h. Antibody modified-PC membranes were incubated with contaminated bacterial water for selective capturing which were detected by synthesized novel bioconjugate probe. Core–shell architecture of polymeric nanoparticles endows them with aqueous stabilization and keto-enolic functionalities making them usable for covalently linking S. typhi antibodies without any crosslinker or activator. Bradford analysis revealed that one nanoparticle has an average of 3.51 × 10{sup −19} g or 21 × 10{sup 4} bound S. typhi Ab molecules. Analysis of the regions of interest (ROI) in fluorescent micrographs of modified fluoroimmunoassay showed higher detection sensitivity of 5 × 10{sup 2} cells/mL due to signal amplification unlike conventional naked dye FITC-Ab conjugate. Fluorescence of pyrene dye remained same on immobilization of biomolecules and nanoparticles showed stable fluorescent intensity under prolong exposure to laser owing to protective polymeric layer allowing accurate identification of bacteria. Surface-functionalized PC matrix and fluorescent label NPs permit covalent interactions among biomolecules enhancing signal acquisitions showing higher detection efficiency as compared to conventional microtiter plate-based system. Our novel immunoassay has the potential to be explored as rapid detection method for identifying S. typhi contaminations in water.Graphical Abstract.

  10. Fluorescence Detection and Discrimination of ss- and ds-DNA with a Water Soluble Oligopyrene Derivative

    Directory of Open Access Journals (Sweden)

    Gaoquan Shi

    2009-06-01

    Full Text Available A novel water-soluble cationic conjugated oligopyrene derivative, oligo(N1,N1,N1,N4,N4,N4-hexamethyl-2-(4-(pyren-1-yl butane-1,4-diaminium bromide (OHPBDB, was synthesized by a combination of chemical and electrochemical synthesis techniques. Each oligomer chain has five pyrene derivative repeating units and brings 10 positive charges. OHPBDB showed high and rapid fluorescence quenching in aqueous media upon addition of trace amounts of single-stranded (ss and double-stranded (ds DNA. The Stern-Volmer constants for ss- and ds-DNA were measured to be as high as 1.3 × 108 mol-1·L and 1.2 × 108 mol-1·L, respectively. On the other hand, distinct fluorescence enhancement of OHPBDB upon addition of large amount of ss-DNA or ds-DNA was observed. Furthermore, ss-DNA showed much stronger fluorescence enhancement than that of ds-DNA, thus yielding a clear and simple signal useful for the discrimination between ss- and ds-DNA in aqueous media.

  11. In Vitro and In Vivo Evaluation of Alexa Fluor 680-Bombesin[7–14]NH2 Peptide Conjugate, a High-Affinity Fluorescent Probe with High Selectivity for the Gastrin-Releasing Peptide Receptor

    Directory of Open Access Journals (Sweden)

    Lixin Ma

    2007-05-01

    Full Text Available Gastrin-releasing peptide (GRP receptors are overexpressed on several types of human cancer cells, including breast, prostate, small cell lung, and pancreatic cancers. Bombesin (BBN, a 14–amino acid peptide that is an analogue of human GRP, binds to GRP receptors with very high affinity and specificity. The aim of this study was to develop a new fluorescent probe based on BBN having high tumor uptake and optimal pharmacokinetics for specific targeting and optical imaging of human breast cancer tissue. In this study, solid-phase peptide synthesis was used to produce H2N-glycylglycylglycine-BBN[7–14]NH2 peptide with the following general sequence: H2N-G-G-G-Q-W-A-V-G-H-L-M-(NH2. This conjugate was purified by reversed-phase high-performance liquid chromatography and characterized by electrospray-ionization mass spectra. The fluorescent probe Alexa Fluor 680-G-G-G-BBN[7–14]NH2 conjugate was prepared by reaction of Alexa Fluor 680 succinimidyl ester to H2N-G-G-G-BBN[7–14]NH2 in dimethylformamide (DMF. In vitro competitive binding assays, using 125I-Tyr4-BBN as the radiolabeling gold standard, demonstrated an inhibitory concentration 50% value of 7.7 ± 1.4 nM in human T-47D breast cancer cells. Confocal fluorescence microscopy images of Alexa Fluor 680-G-G-G-BBN[7–14]NH2 in human T-47D breast cancer cells indicated specific uptake, internalization, and receptor blocking of the fluorescent bioprobe in vitro. In vivo investigations in SCID mice bearing xenografted T-47D breast cancer lesions demonstrated the ability of this new conjugate to specifically target tumor tissue with high selectivity and affinity.

  12. Flow cytometric measurement of the metabolism of benzo[a]pyrene by mouse liver cells in culture

    International Nuclear Information System (INIS)

    Bartholomew, J.C.; Wade, C.G.; Dougherty, K.K.

    1984-01-01

    The metabolism of benzo[a]pyrene in individual cells was monitored by flow cytometry. The measurements are based on the alterations that occur in the fluorescence emission spectrum of benzo[a]pyrene when it is converted to various metabolites. Using present instrumentation the technique could easily detect 1x10 6 molecules per cells of benzo[a]pyrene and 1x10 7 molecules per cell of the diol epoxide. The analysis of C3H IOT 1/2 mouse fibroblasts growing in culture indicated that there was heterogeneity in the conversion of the parent compound into diol epoxide derivatives suggesting that some variation in sensitivity to transformation by benzo[a]pyrene may be due to differences in cellular metabolism. The technique allows sensitive detection of metabolites in viable cells, and provides a new approach to the study of factors that influence both metabolism and transformation. (orig.)

  13. Species differences in biliary excretion of benzo[a]pyrene

    International Nuclear Information System (INIS)

    Weyand, E.H.; Bevan, D.R.

    1986-01-01

    Biliary excretion of benzo[a]pyrene (B[a]P) was investigated in rats, hamsters, and guinea pigs following intratracheal administration. [ 3 H]-B[a]P, in amounts of approximately 150 ng or 350 μg, was instilled into lungs and amounts of radioactivity excreted in bile were monitored for six hrs following administration. Differences in biliary excretion of [ 3 H]-B[a]P and/or metabolites among species were observed at low doses but not at high doses. Six hours after instillation of a low dose of B[a]P, 70, 54, and 62% of the dose was excreted in bile of rats, hamsters, and guinea pigs, respectively. Upon administration of the higher dose of B[a]P, approximately 50% of the dose was excreted in bile in six hrs by all species. Thus, rats and guinea pigs exhibit differences in biliary excretion of low and high doses of B[a]P whereas hamsters do not. Profiles of phase II metabolites in rats and hamsters were similar at both low and high doses, with the majority of metabolites being glucuronides and thioether conjugates. However, differences in relative amounts of these conjugates were observed between the two doses, with a shift towards a greater proportion of glucuronides at the higher dose. Metabolites in bile from guinea pigs were primarily thioether conjugates, which accounted for 88% of metabolites at the low dose and 95% at the high dose

  14. Microbial transformation of 6-nitrobenzo[a]pyrene

    International Nuclear Information System (INIS)

    Millner, G.C.; Fu, P.P.; Cerniglia, C.E.

    1986-01-01

    The fungal metabolism of the potent mutagenic and carcinogenic nitropolycyclic aromatic hydrocarbon (nitro-PAH) 6-nitrobenzo[a]pyrene (6-NO 2 -BaP) was investigated. Cunninghamella elegans was incubated with 6-NO 2 -BaP for periods ranging between 1 and 7 d, and the metabolites formed were separated by high-performance liquid chromatography and identified by their UV-visible absorption, mass, and 1 H nuclear magnetic resonance spectra. The results of the study indicate that C. elegans metabolized 6-NO 2 -BaP to glucoside and sulfate conjugates of 1- and 3-hydroxy 6-NO 2 -BaP and suggests that glycosylation and sulfation reactions may represent detoxification pathways in the fungal metabolism of nitro-PAHs. Experiments using [G- 3 H]-6-NO 2 -BaP indicated that C. elegans metabolized 62% of 6-NO 2 -BaP with 168 h. The data also indicated that the nitro group at the C-6 position of benzo[a]pyrene blocked metabolism at the regions peri to the nitro substituent (C-7, C-8 positions) and enhanced metabolism at the C-1 and C-3 positions. The ability of the fungus C. elegans to metabolize 6-NO 2 -BaP to biologically inactive compounds may have practical applications in the detoxification of nitro-PAH-contaminated wastes

  15. Luminescence quenching by heavy metal ions of probes based on anthracene, pyrene, and eosin in human serum albumin

    Science.gov (United States)

    Naumova, E. V.; Melnikov, A. G.; Melnikov, G. V.

    2013-05-01

    Fluorescence and phosphorescence quenching processes of polar and non-polar luminescent probes associated with human serum albumin (HSA) in phosphate buffer at pH 7.4 were studied. Stern-Volmer quenching constants of anthracene and pyrene fluorescence and eosin phosphorescence and rate constants for quenching of eosin triplet states were determined. The polarity index of pyrene bound to HSA was obtained as a function of thallium nitrate concentration. The influences of structural changes in the proteins that were stimulated by heavy-metal salts and of screening of protein charges by salt ions on quenching processes of singlet and triplet states of the probes were found.

  16. Preparation and Characterization of Self-Assembled Nanoparticles of Hyaluronic Acid-Deoxycholic Acid Conjugates

    Directory of Open Access Journals (Sweden)

    Xuemeng Dong

    2010-01-01

    Full Text Available Novel amphiphilic biopolymers were synthesized using hyaluronic acid (HA as a hydrophilic segment and deoxycholic acid (DOCA as a hydrophobic segment by a 1-ethyl-3-(3-dimethylaminopropyl carbodiimide mediated coupling reaction. The structural characteristics of the HA-DOCA conjugates were investigated using H1 NMR. Self-assembled nanoparticles were prepared based on HA-DOCA conjugates, and its characteristics were investigated using dynamic laser light scattering, transmission electron microscopy (TEM, and fluorescence spectroscopy. The mean diameter was about 293.5 nm with unimodal size distribution in distilled water. The TEM images revealed that the shape of HA-DOCA self-aggregates was spherical. The critical aggregation concentration (CAC was in the range of 0.025–0.056 mg/mL. The partition equilibrium constant (Kv of pyrene in self-aggregates solution was from 1.45×104 to 3.64×104. The aggregation number of DOCA groups per hydrophobic microdomain, estimated by the fluorescence quenching method using cetylpyridinium chloride, increased with increasing degree of substitution.

  17. Bioremediating silty soil contaminated by phenanthrene, pyrene ...

    African Journals Online (AJOL)

    sunny t

    benzo(a)pyrene using Bacillus sp. and Pseudomonas sp.: Biosurfactant/Beta vulgaris ... potential human mutagens and carcinogens (Grimmer,. 1983). Chemical and ...... of naphthalene on zeolite from aqueous solution. J. Colloid Interf. Sci.

  18. Selective binding of pyrene in subdomain IB of human serum albumin: Combining energy transfer spectroscopy and molecular modelling to understand protein binding flexibility

    Science.gov (United States)

    Ling, Irene; Taha, Mohamed; Al-Sharji, Nada A.; Abou-Zied, Osama K.

    2018-04-01

    The ability of human serum albumin (HSA) to bind medium-sized hydrophobic molecules is important for the distribution, metabolism, and efficacy of many drugs. Herein, the interaction between pyrene, a hydrophobic fluorescent probe, and HSA was thoroughly investigated using steady-state and time-resolved fluorescence techniques, ligand docking, and molecular dynamics (MD) simulations. A slight quenching of the fluorescence signal from Trp214 (the sole tryptophan residue in the protein) in the presence of pyrene was used to determine the ligand binding site in the protein, using Förster's resonance energy transfer (FRET) theory. The estimated FRET apparent distance between pyrene and Trp214 was 27 Å, which was closely reproduced by the docking analysis (29 Å) and MD simulation (32 Å). The highest affinity site for pyrene was found to be in subdomain IB from the docking results. The calculated equilibrium structure of the complex using MD simulation shows that the ligand is largely stabilized by hydrophobic interaction with Phe165, Phe127, and the nonpolar moieties of Tyr138 and Tyr161. The fluorescence vibronic peak ratio I1/I3 of bound pyrene inside HSA indicates the presence of polar effect in the local environment of pyrene which is less than that of free pyrene in buffer. This was clarified by the MD simulation results in which an average of 5.7 water molecules were found within 0.5 nm of pyrene in the binding site. Comparing the fluorescence signals and lifetimes of pyrene inside HSA to that free in buffer, the high tendency of pyrene to form dimer was almost completely suppressed inside HSA, indicating a high selectivity of the binding pocket toward pyrene monomer. The current results emphasize the ability of HSA, as a major carrier of several drugs and ligands in blood, to bind hydrophobic molecules in cavities other than subdomain IIA which is known to bind most hydrophobic drugs. This ability stems from the nature of the amino acids forming the binding

  19. Pyrene functionalized molecular beacon with pH-sensitive i-motif in a loop.

    Science.gov (United States)

    Dembska, Anna; Juskowiak, Bernard

    2015-01-01

    In this work, we present a spectral characterization of pH-sensitive system, which combines the i-motif properties with the spatially sensitive fluorescence signal of pyrene molecules attached to hairpin ends. The excimer production (fluorescence max. ∼480 nm) by pyrene labels at the ends of the molecular beacon is driven by pH-dependent i-motif formation in the loop. To illustrate the performance and reversible work of our systems, we performed the experiments with repeatedly pH cycling between pH values of 7.5±0.3 and 6.5±0.3. The sensor gives analytical response in excimer-monomer switching mode in narrow pH range (1.5 pH units) and exhibits high pH resolution (0.1 pH unit). Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Branched DNA nanostructures efficiently stabilised and monitored by novel pyrene-perylene 2'-α-l-amino-LNA FRET pairs

    DEFF Research Database (Denmark)

    Astakhova, I Kira; Santhosh Kumar, T; Campbell, Meghan A

    2013-01-01

    Novel pyrene-perylene α-l-LNA FRET pairs described herein effectively detect assembly of 2- and 3-way branched DNA nanostructures prepared by postsynthetic microwave-assisted CuAAC click chemistry. The fluorescent signalling of assembly by internally positioned FRET pairs is achieved with low...

  1. The dependence of the ultrafast relaxation kinetics of the S2 and S1 states in β-carotene homologs and lycopene on conjugation length studied by femtosecond time-resolved absorption and Kerr-gate fluorescence spectroscopies

    Science.gov (United States)

    Kosumi, Daisuke; Fujiwara, Masazumi; Fujii, Ritsuko; Cogdell, Richard J.; Hashimoto, Hideki; Yoshizawa, Masayuki

    2009-06-01

    The ultrafast relaxation kinetics of all-trans-β-carotene homologs with varying numbers of conjugated double bonds n(n =7-15) and lycopene (n =11) has been investigated using femtosecond time-resolved absorption and Kerr-gate fluorescence spectroscopies, both carried out under identical excitation conditions. The nonradiative relaxation rates of the optically allowed S2(1Bu+1) state were precisely determined by the time-resolved fluorescence. The kinetics of the optically forbidden S1(2Ag-1) state were observed by the time-resolved absorption measurements. The dependence of the S1 relaxation rates upon the conjugation length is adequately described by application of the energy gap law. In contrast to this, the nonradiative relaxation rates of S2 have a minimum at n =9 and show a reverse energy gap law dependence for values of n above 11. This anomalous behavior of the S2 relaxation rates can be explained by the presence of an intermediate state (here called the Sx state) located between the S2 and S1 states at large values of n (such as n =11). The presence of such an intermediate state would then result in the following sequential relaxation pathway S2→Sx→S1→S0. A model based on conical intersections between the potential energy curves of these excited singlet states can readily explain the measured relationships between the decay rates and the energy gaps.

  2. Pyrene absorption can be a convenient method for probing critical micellar concentration (cmc) and indexing micellar polarity.

    Science.gov (United States)

    Basu Ray, Gargi; Chakraborty, Indranil; Moulik, Satya P

    2006-02-01

    The critical micellar concentration (cmc) of both ionic and non-ionic surfactants can be conveniently determined from the measurements of UV absorption of pyrene in surfactant solution. The results on a number of surfactants have agreed with that realized from pyrene fluorescence measurements as well as that obtained following conductometric, tensiometric and calorimetric methods. The absorbance vs [surfactant] profiles for all the major UV spectral peaks of pyrene have been found to be sigmoidal in nature which were analyzed according to Sigmoidal-Boltzmann equation (SBE) to evaluate the cmcs of the studied surfactants. The difference between the initial and the final asymptotes (a(i) and a(f), respectively) of the sigmoidal profile, Delta a = (a(f)-a(i)) and the slope of the sigmoid, S(sig) have been observed to depend on the type of the surfactant. The Delta a has shown a linear correlation with the ratio of the fluorescence intensities of the first and the third vibronic peaks, I1/I3 of pyrene which is considered as a measure of the environmental polarity (herein micellar interior) of the probe (pyrene). Thus, Delta a values have the prospect for use as another index for the estimation of polarity of micellar interior.

  3. Photoluminescence in conjugated polymers

    International Nuclear Information System (INIS)

    Furst, J.E.; Laugesen, R.; Dastoor, P.; McNeill, C.

    2002-01-01

    Full text: Conjugated polymers combine the electronic and optical properties of semiconductors with the processability of polymers. They contain a sequence of alternate single and double carbon bonds so that the overlap of unhybridised p z orbitals creates a delocalised ρ system which gives semiconducting properties with p-bonding (valence) and p* -antibonding (conduction) bands. Photoluminesence (PL) in conjugated polymers results from the radiative decay of singlet excitons confined to a single chain. The present work is the first in a series of studies in our laboratory that will characterize the optical properties of conjugated polymers. The experiment involves the illumination of thin films of conjugated polymer with UV light (I=360 nm) and observing the subsequent fluorescence using a custom-built, fluorescence spectrometer. Photoluminesence spectra provide basic information about the structure of the polymer film. A typical spectrum is shown in the accompanying figure. The position of the first peak is related to the polymer chain length and resolved multiple vibronic peaks are an indication of film structure and morphology. We will also present results related to the optical degradation of these materials when exposed to air and UV light

  4. A fluorescent probe for ecstasy.

    Science.gov (United States)

    Masseroni, D; Biavardi, E; Genovese, D; Rampazzo, E; Prodi, L; Dalcanale, E

    2015-08-18

    A nanostructure formed by the insertion in silica nanoparticles of a pyrene-derivatized cavitand, which is able to specifically recognize ecstasy in water, is presented. The absence of effects from interferents and an efficient electron transfer process occurring after complexation of ecstasy, makes this system an efficient fluorescent probe for this popular drug.

  5. Bacillus subtilis is a Potential Degrader of Pyrene and Benzo[a]pyrene

    Directory of Open Access Journals (Sweden)

    Lynette Ekunwe

    2005-08-01

    Full Text Available Polycyclic Aromatic Hydrocarbons (PAHs are a group of compounds that pose many health threats to human and animal life. They occur in nature as a result of incomplete combustion of organic matter, as well as from many anthropogenic sources including cigarette smoke and automobile exhaust. PAHs have been reported to cause liver damage, red blood cell damage and a variety of cancers. Because of this, methods to reduce the amount of PAHs in the environment are continuously being sought. The purpose of this study was to find soil bacteria capable of degrading high molecular weight PAHs, such as pyrene (Pyr and benzo[a]pyrene (BaP, which contain more than three benzene rings and so persist in the environment. Bacillus subtilis, identified by fatty acid methyl ester (FAME analysis, was isolated from PAH contaminated soil. Because it grew in the presence of 33μg/ml each of pyrene, 1-AP and 1-HP, its biodegradation capabilities were assessed. It was found that after a four-day incubation period at 30oC in 20μg/ml pyrene or benzo[a]pyrene, B. subtilis was able to transform approximately 40% and 50% pyrene and benzo[a]pyrene, respectively. This is the first report implicating B. subtilis in PAH degradation. Whether or not the intermediates resulting from the transformation are more toxic than their parent compounds, and whether B. subtilis is capable of mineralizing pyrene or benzo[a]pyrene to carbon dioxide and water, remains to be evaluated.

  6. The application of pH-sensitive fluorescent dyes in lactic acid bacteria reveals distinct extrusion systems for unmodified and conjugated dyes

    NARCIS (Netherlands)

    Glaasker, E; Konings, W.N; Poolman, B.

    1996-01-01

    Intracellular pH in bacteria can be measured efficiently between internal pH values of 6.5 and 8.5 with the fluorescent pH indicator 2',7'-bis-(2-carboxyethyl)-5[and-6]-carboxyfluorescein (BCECF). A new fluorescent pH probe with a lower pK(a)(app) than BCECF was synthesized from fluorescein

  7. Preparation of 1-pyrenebutyric acid and pyrene submicron dots by laser-induced molecular micro-jet implantation

    International Nuclear Information System (INIS)

    Pihosh, Y.; Goto, M.; Kasahara, A.; Tosa, M.

    2009-01-01

    Pyrene and 1-pyrenebuturic acid molecules were deposited on glass and copper substrates with the formation of submicron dots by laser-induced molecular micro-jet implantation through polar and non-polar liquid layers. The size of the smallest 1-pyrenebuturic acid molecules dots prepared on a glass substrate by implantation through water and diiodomethane was estimated to be about 400 nm and 300 nm at laser fluences of 235 J/cm 2 and 326 J/cm 2 , respectively. The fluorescence and the Raman spectra showed that the implanted 1-pyrenebutyric acid molecules did not decompose during the implantation process. The smallest size of a pyrene dot was 700 nm at the laser fluence of 378 J/cm 2 . However, the pyrene dots could be formed only by implantation through a water layer.

  8. Bioremediating silty soil contaminated by phenanthrene, pyrene ...

    African Journals Online (AJOL)

    ... followed in the order of their increasing molecular weight. The synergy of the bacterial isolates and the biosurfactant produced from B. vulgaris agrowaste could be used in environmental bioremediation of PAHs even in silty soil. Keywords: Benz(a)anthracene, benzo(a)pyrene, bioremediation, biosurfactant, Beta vulgaris, ...

  9. Bio-Conjugates for Nanoscale Applications

    DEFF Research Database (Denmark)

    Villadsen, Klaus

    Bio-conjugates for Nanoscale Applications is the title of this thesis, which covers three different projects in chemical bio-conjugation research, namely synthesis and applications of: Lipidated fluorescent peptides, carbohydrate oxime-azide linkers and N-aryl O-R2 oxyamine derivatives. Lipidated...

  10. Fluorescently labeled bionanotransporters of nucleic acid based on carbon nanotubes

    International Nuclear Information System (INIS)

    Novopashina, D.S.; Apartsin, E.K.; Venyaminova, A.G.

    2012-01-01

    We propose an approach to the design of a new type of hybrids of oligonucleotides with fluorescein-functionalized single-walled carbon nanotubes. The approach is based on stacking interactions of functionalized nanotubes with pyrene residues in conjugates of oligonucleotides. The amino- and fluorescein-modified single walled carbon nanotubes are obtained, and their physico-chemical properties are investigated. The effect of the functionalization type of carbon nanotubes on the efficacy of the sorption of pyrene conjugates of oligonucleotides was examined. The proposed noncovalent hybrids of fluorescein-labeled carbon nanotubes with oligonucleotides may be used for the intracellular transport of functional nucleic acids.

  11. High-mobility pyrene-based semiconductor for organic thin-film transistors.

    Science.gov (United States)

    Cho, Hyunduck; Lee, Sunyoung; Cho, Nam Sung; Jabbour, Ghassan E; Kwak, Jeonghun; Hwang, Do-Hoon; Lee, Changhee

    2013-05-01

    Numerous conjugated oligoacenes and polythiophenes are being heavily studied in the search for high-mobility organic semiconductors. Although many researchers have designed fused aromatic compounds as organic semiconductors for organic thin-film transistors (OTFTs), pyrene-based organic semiconductors with high mobilities and on-off current ratios have not yet been reported. Here, we introduce a new pyrene-based p-type organic semiconductor showing liquid crystal behavior. The thin film characteristics of this material are investigated by varying the substrate temperature during the deposition and the gate dielectric condition using the surface modification with a self-assembled monolayer, and systematically studied in correlation with the performances of transistor devices with this compound. OTFT fabricated under the optimum deposition conditions of this compound, namely, 1,6-bis(5'-octyl-2,2'-bithiophen-5-yl)pyrene (BOBTP) shows a high-performance transistor behavior with a field-effect mobility of 2.1 cm(2) V(-1) s(-1) and an on-off current ratio of 7.6 × 10(6) and enhanced long-term stability compared to the pentacene thin-film transistor.

  12. Sublethal toxicity and biotransformation of pyrene in Lumbriculus variegatus (Oligochaeta)

    International Nuclear Information System (INIS)

    Maeenpaeae, K.; Leppaenen, M.T.; Kukkonen, J.V.K.

    2009-01-01

    The aim of this work was to study the toxicity and biotransformation of polyaromatic hydrocarbon (PAH) pyrene in the oligochaete aquatic worm, Lumbriculus variegatus. PAHs are ubiquitous environmental pollutants that pose a hazard to aquatic organisms, and metabolizing capability is poorly known in the case of many invertebrate species. To study the toxicity and biotransformation of pyrene, the worm was exposed for 15 days to various concentrations of water-borne pyrene. The dorsal blood vessel pulse rate was used as a sublethal endpoint. Pyrene biotransformation by L. variegatus was studied and the critical body residues (CBR) were estimated for pyrene toxicity. The toxicokinetics of pyrene uptake was evaluated. A combination of radiolabeled ( 14 C) and nonlabeled pyrene was used in the exposures, and liquid scintillation counting (LSC) and high-pressure liquid chromatography were employed in both water and tissue residue analyses. The results showed that L. variegatus was moderately able to metabolize pyrene to 1-hydroxypyrene (1-HP), thus demonstrating that the phase-I-like oxidizing enzyme system metabolizes pyrene in L. variegatus. The amount of the 1-HP was 1-2% of the amount of pyrene in the worm tissues. The exposure to pyrene reduced the blood vessel pulse rate significantly (p < 0.05), showing that pyrene had a narcotic effect. The estimated CBRs remained constant during the exposure time, varying from 0.120 to 0.174 mmol pyrene/kg worm wet weight. The bioconcentration factors (BCF) decreased as exposure concentration increased. It was suggested that the increased toxicity of pyrene accounted for the decrease in BCFs by lowering the activity of the organism

  13. Charge-transfer interaction mediated organogels from 18β-glycyrrhetinic acid appended pyrene

    Directory of Open Access Journals (Sweden)

    Jun Hu

    2013-12-01

    Full Text Available We describe herein the two-component charge-transfer (CT interaction induced organogel formation with 18β-glycyrrhetinic acid appended pyrene (GA-pyrene, 3 as the donor, and 2,4,7-trinitrofluorenone (TNF, 4 as the acceptor. The use of TNF (4 as a versatile electron acceptor in the formation of CT gels is demonstrated through the formation of gels in a variety of solvents. Thermal stability, stoichiometry, scanning electron microscopy (SEM, optical micrographs, and circular dichroism (CD are performed on these CT gels to investigate their thermal and assembly properties. UV–vis, fluorescence, mass spectrometric as well as variable-temperature 1H NMR experiments on these gels suggest that the CT interaction is one of the major driving forces for the formation of these organogels.

  14. Synthesis, crystal structure and aggregation-induced emission of a new pyrene-based compound, 3,3-diphenyl-2-[4-(pyren-1-ylphenyl]acrylonitrile

    Directory of Open Access Journals (Sweden)

    Bao-Xi Miao

    2018-05-01

    Full Text Available The title organic compound, C37H23N, crystallizing in the triclinic space group P\\overline{1}, has been designed, synthesized and characterized by single-crystal X-ray diffaction, MS, NMR and elemental analysis. There are alternating relatively strong and weak intermolecular π–π interactions between adjacent pyrene ring systems, forming a one-dimensional supramolecular structure. The compound is weakly fluorescent in THF solution, but it is highly emissive in the condensed phase, revealing distinct aggregation-induced emission (AIE characteristics.

  15. Complexation (cucurbit[6]uril-pyrene): Thermodynamic and spectroscopic properties

    Energy Technology Data Exchange (ETDEWEB)

    Sueldo Occello, Valeria N.; Rossi, Rita H. de; Veglia, Alicia V., E-mail: aveglia@fcq.unc.edu.ar

    2015-02-15

    The influence of the macrocyclic compound cucurbit[6]uril (CB6) on the photophysical properties of the fluorophore pyrene (PYR) has been studied. Guest–host interaction was observed by UV–visible spectroscopy and spectrofluorimetry. The fluorescence of PYR was significantly increased in the presence of CB6. The binding equilibrium constants for the complex with 1:1 stoichiometry were determined in HCOOH 55% w/v. The values of the association constants, K{sub A}, and the fluorescence quantum yield ratios between complexed and free substrate, ϕ{sup PYR–CB6}/ϕ{sup PYR}, at different temperatures were (3.1±0.9)×10{sup 2} M{sup −1} and (5.1±0.2), (3.6±0.5)×10{sup 2} M{sup −1} and (5.9±0.1), (4.8±0.7)×10{sup 2} M{sup −1} and (5.5±0.1) at 15.0 °C, 25.0 °C and 40.0 °C, respectively. The enthalpic and entropic contributions to the complexation process were determined, yielding ΔS=(92±3) J mol{sup −1} K{sup −1} and ΔH=(13±1) kJ mol{sup −1}. From these results it can be concluded that the complex formation is mainly driven by the entropic term. The forces involved in the complexation are interpreted from the sign and magnitude of the thermodynamic parameters obtained. The partial inclusion of PYR or the formation of a suspended complex is proposed in base of all the data. The interaction is also demonstrated in the solid state by differential scanning calorimetric (DSC) measurements. - Highlights: • The cucurbit[6]uril (CB6) effects on the absorption and fluorescence of pyrene (PYR) were analyzed. • The association constant (K{sub A}) and the stoichiometry of the complex were determined. • The complex formation was confirmed by differential scanning calorimetry (DSC). • The thermodynamic parameters were determined. • The hydrophobic entropic contribution is the main driving force for the PYR–CB6 complex formation.

  16. Fluorescent Sterols and Cholesteryl Esters as Probes for Intracellular Cholesterol Transport

    Science.gov (United States)

    Solanko, Katarzyna A.; Modzel, Maciej; Solanko, Lukasz M.; Wüstner, Daniel

    2015-01-01

    Cholesterol transport between cellular organelles comprised vesicular trafficking and nonvesicular exchange; these processes are often studied by quantitative fluorescence microscopy. A major challenge for using this approach is producing analogs of cholesterol with suitable brightness and structural and chemical properties comparable with those of cholesterol. This review surveys currently used fluorescent sterols with respect to their behavior in model membranes, their photophysical properties, as well as their transport and metabolism in cells. In the first part, several intrinsically fluorescent sterols, such as dehydroergosterol or cholestatrienol, are discussed. These polyene sterols (P-sterols) contain three conjugated double bonds in the steroid ring system, giving them slight fluorescence in ultraviolet light. We discuss the properties of P-sterols relative to cholesterol, outline their chemical synthesis, and explain how to image them in living cells and organisms. In particular, we show that P-sterol esters inserted into low-density lipoprotein can be tracked in the fibroblasts of Niemann–Pick disease using high-resolution deconvolution microscopy. We also describe fluorophore-tagged cholesterol probes, such as BODIPY-, NBD-, Dansyl-, or Pyrene-tagged cholesterol, and eventual esters of these analogs. Finally, we survey the latest developments in the synthesis and use of alkyne cholesterol analogs to be labeled with fluorophores by click chemistry and discuss the potential of all approaches for future applications. PMID:27330304

  17. Removal of pyrene and benzo(a)pyrene micropollutant from water via adsorption by green synthesized iron oxide nanoparticles

    Science.gov (United States)

    Hassan, Saad S. M.; Abdel-Shafy, Hussein I.; Mansour, Mona S. M.

    2018-03-01

    Polycyclic aromatic hydrocarbons (PAHs) in water are classified as organic micropollutants, which are carcinogenic even in very low concentration (ppb). In this study the green synthesized iron oxide nanoparticles (IONPs) were green synthesized at room temperature by using pomegranate peel extract. The green synthesized IONPs were used for adsorbing benzo(a)pyrene and pyrene (PAHs) from water. Factors affecting the adsorption were investigated. These factors are: nanoparticles dose, pH, temperature, and initial concentration of PAHs. The overall results showed that the maximum adsorption capacities of IONPs towards pyrene and benzo(a)pyrene were 2.8 and 0.029 mg g-1, respectively. The thermodynamic study indicated an exothermic adsorption process of pyrene and benzo(a)pyrene. The kinetic and isotherm studies were carried out. The obtained data revealed that the adsorption process follows a pseudo-second order mechanism and obeys Langmuir isotherm model. In addition, the IONPs proved to be a potential candidate for the adsorption of pyrene and benzo(a)pyrene even after five cycles of use and regeneration. The investigation was extended using semi-pilot plant to remove the studied PAHs from artificially contaminated water. The results showed that the IONPs was capable to remove the pyrene and benzo (a) pyrene at the rate of 98.5 and 99%, respectively. It also can be used as disinfectant.

  18. Nine New Fluorescent Probes

    Science.gov (United States)

    Lin, Tsung-I.; Jovanovic, Misa V.; Dowben, Robert M.

    1989-06-01

    Absorption and fluorescence spectroscopic studies are reported here for nine new fluorescent probes recently synthesized in our laboratories: four pyrene derivatives with substituents of (i) 1,3-diacetoxy-6,8-dichlorosulfonyl, (ii) 1,3-dihydroxy-6,8-disodiumsulfonate, (iii) 1,3-disodiumsulfonate, and (iv) l-ethoxy-3,6,8-trisodiumsulfonate groups, and five [7-julolidino] coumarin derivatives with substituents of (v) 3-carboxylate-4-methyl, (vi) 3- methylcarboxylate, (vii) 3-acetate-4-methyl, (viii) 3-propionate-4-methyl, and (ix) 3-sulfonate-4-methyl groups. Pyrene compounds i and ii and coumarin compounds v and vi exhibit interesting absorbance and fluorescence properties: their absorption maxima are red shifted compared to the parent compound to the blue-green region, and the band width broadens considerably. All four blue-absorbing dyes fluoresce intensely in the green region, and the two pyrene compounds emit at such long wavelengths without formation of excimers. The fluorescence properties of these compounds are quite environment-sensitive: considerable spectral shifts and fluorescence intensity changes have been observed in the pH range from 3 to 10 and in a wide variety of polar and hydrophobic solvents with vastly different dielectric constants. The high extinction and fluorescence quantum yield of these probes make them ideal fluorescent labeling reagents for proteins, antibodies, nucleic acids, and cellular organelles. The pH and hydrophobicity-dependent fluorescence changes can be utilized as optical pH and/or hydrophobicity indicators for mapping environmental difference in various cellular components in a single cell. Since all nine probes absorb in the UV, but emit at different wavelengths in the visible, these two groups of compounds offer an advantage of utilizing a single monochromatic light source (e.g., a nitrogen laser) to achieve multi-wavelength detection for flow cytometry application. As a first step to explore potential application in

  19. Multi step FRET among three laser dyes Pyrene, Acriflavine and Rhodamine B

    International Nuclear Information System (INIS)

    Saha, Jaba; Dey, Dibyendu; Roy, Arpan Datta; Bhattacharjee, D.; Hussain, Syed Arshad

    2016-01-01

    Fluorescence Resonance Energy Transfer (FRET) system using three dyes has been demonstrated. It has been observed that multi step energy transfer occurred from Pyrene to Rhodamine B via Acriflavine. Here Acriflavine acts as an antenna to receive energy from Pyrene and transfer the same to Rhodamine B. This multi step FRET system is advantageous compared to the conventional FRET as this can be used to study molecular level interaction beyond conventional FRET distance (1–10 nm) as well as studying multi-branched macromolecules. The introduction of clay enhances the FRET efficiencies among the dye pair, which is an advantage to make the multi step system more useful. Similar approach can be used for increasing FRET efficiencies by using other dyes. - Highlights: • Multi-step FRET occurred from Pyrene (Py) to Rhodamine B (RhB) via Acriflavine (Acf). • Acf acts as an antenna to receive energy from Py and to transfer energy to RhB. • Multi-step FRET can be used to study molecular level interaction beyond 1–10 nm. • Incorporation of nanoclay laponite enhances the energy transfer efficiency.

  20. Conjugated and fluorescent polymer based on dansyl-substituted pyrrole prepared by electrochemical polymerization in acetonitrile containing boron trifluoride diethyl etherate

    International Nuclear Information System (INIS)

    Almeida, Andresa K.A.; Dias, Jéssica M.M.; Silva, Ana Julia C.; Santos, Diego P.; Navarro, Marcelo; Tonholo, Josealdo; Goulart, Marília O.F.; Ribeiro, Adriana S.

    2014-01-01

    Graphical abstract: - Highlights: • A fluorescent pyrrole derivative bearing a dansyl substituent (PyPDG) was synthesized. • PyPDG was electropolymerized onto ITO in (C 4 H 9 ) 4 NBF 4 /CH 3 CN/BFEE mixed electrolyte. • The resulting polymer (PPyPDG) films displayed electrochromic behavior. • PPyPDG is a good green light emitter material. - Abstract: A fluorescent pyrrole derivative bearing a dansyl substituent was prepared by a simple synthetic route and electropolymerized onto Indium Tin Oxide (ITO) electrodes. The presence of the dansyl group in the monomer precursor prevents the electropolymerization in usual systems, such as (C 4 H 9 ) 4 NBF 4 in acetonitrile (CH 3 CN). For this reason, it was added 20% boron trifluoride diethyl etherate (BFEE) to this system, to achieve electropolymerization. The resulting poly[3-(N-pyrrolyl)propyl dansylglycinate] (PPyPDG) films displayed electrochromic behavior. Their color varied from greenish-yellow, in the neutral state, to greyish-green, in the oxidized state; moreover PPyPDG is a good green light emitter material. Therefore, PPyPDG films might be potentially applicable in displays and optoelectronic devices

  1. Imaging Dose-dependent Pharmacokinetics of an RGD-Fluorescent Dye Conjugate Targeted to αvβ3 Receptor Expressed in Kaposi's Sarcoma

    Directory of Open Access Journals (Sweden)

    Sunkuk Kwon

    2005-04-01

    Full Text Available Dynamic fluorescence images were obtained from xenografts bearing a subcutaneous human Kaposi's sarcoma (KS1767 immediately following the intravenous injection of an integrin-receptor targeting Cy5.5-c(KRGDf at a dose ranging from 0.75 to 6 nmol/mouse. The fluorescence images were acquired using an intensified charge-coupled device system and were analyzed with a three-compartment pharmacokinetic (PK model to determine uptake parameters in the tumor and normal tissue regions of interest as a function of administered dose. Our results show that the uptake of Cy5.5-c(KRGDf in tumor regions were: (i significantly greater than the contralateral normal tissue regions; (ii linearly increased with dose of Cy5.5-c(KRGDf up to 1.5 nmol/mouse; and (iii blocked by preinjection of c(KRGDf. Above doses of 1.5 nmol/mouse, the uptake no longer increased with dose, suggesting integrin receptor saturation. In normal tissues, the PK uptake parameters were not influenced by Cy5.5-c(KRGDf dose nor by the preadministration of c(KRGDf.

  2. FLUORESCENCE PROBING OF THE FORMATION OF HYDROPHOBIC MICRODOMAINS BY CROSS-LINKED POLY(ALKYLMETHYLDIALLYLAMMONIUM BROMIDES) IN AQUEOUS-SOLUTION

    NARCIS (Netherlands)

    WANG, GJ; ENGBERTS, J B F N

    Pyrene has been used as a fluorescence probe to investigate the conformational behavior of cross-linked poly(alkylmethyldiallylammonium bromides) in aqueous solutions. Binding of pyrene to hydrophobic microdomains, formed by the polysoaps, is reflected by a change in the ratio I-1/I-3 of the

  3. BODIPY-pyrene and perylene dyads as heavy atom-free singlet oxygen sensitizers

    KAUST Repository

    Filatov, Mikhail A.

    2018-02-23

    Dyads combining BODIPY as an electron acceptor and pyrene or perylene as electron donor subunits were prepared and studied their photophysical properties studied by steady-state and transient spectroscopy. Depending on the structure of the subunits and polarity of the media, the dyads show either bright fluorescence or photo-induced electron transfer (PeT) in solution. Charge-transfer (CT) states formed as a result of PeT and were found to yield triplet excited states of the BODIPY. In the presence of molecular oxygen, the dyads sensitize singlet oxygen (1O2) with quantum yields of up to 0.75.

  4. BODIPY-pyrene and perylene dyads as heavy atom-free singlet oxygen sensitizers

    KAUST Repository

    Filatov, Mikhail A.; Karuthedath, Safakath; Polestshuk, Pavel M.; Callaghan, Susan; Flanagan, Keith J.; Wiesner, Thomas; Laquai, Fré dé ric; Senge, Mathias O.

    2018-01-01

    Dyads combining BODIPY as an electron acceptor and pyrene or perylene as electron donor subunits were prepared and studied their photophysical properties studied by steady-state and transient spectroscopy. Depending on the structure of the subunits and polarity of the media, the dyads show either bright fluorescence or photo-induced electron transfer (PeT) in solution. Charge-transfer (CT) states formed as a result of PeT and were found to yield triplet excited states of the BODIPY. In the presence of molecular oxygen, the dyads sensitize singlet oxygen (1O2) with quantum yields of up to 0.75.

  5. Characterization of the commercially-available fluorescent chloroquine-BODIPY conjugate, LynxTag-CQGREEN, as a marker for chloroquine resistance and uptake in a 96-well plate assay.

    Directory of Open Access Journals (Sweden)

    Cheryl C Y Loh

    Full Text Available Chloroquine was a cheap, extremely effective drug against Plasmodium falciparum until resistance arose. One approach to reversing resistance is the inhibition of chloroquine efflux from its site of action, the parasite digestive vacuole. Chloroquine accumulation studies have traditionally relied on radiolabelled chloroquine, which poses several challenges. There is a need for development of a safe and biologically relevant substitute. We report here a commercially-available green fluorescent chloroquine-BODIPY conjugate, LynxTag-CQGREEN, as a proxy for chloroquine accumulation. This compound localized to the digestive vacuole of the parasite as observed under confocal microscopy, and inhibited growth of chloroquine-sensitive strain 3D7 more extensively than in the resistant strains 7G8 and K1. Microplate reader measurements indicated suppression of LynxTag-CQGREEN efflux after pretreatment of parasites with known reversal agents. Microsomes carrying either sensitive- or resistant-type PfCRT were assayed for uptake; resistant-type PfCRT exhibited increased accumulation of LynxTag-CQGREEN, which was suppressed by pretreatment with known chemosensitizers. Eight laboratory strains and twelve clinical isolates were sequenced for PfCRT and Pgh1 haplotypes previously reported to contribute to drug resistance, and pfmdr1 copy number and chloroquine IC50s were determined. These data were compared with LynxTag-CQGREEN uptake/fluorescence by multiple linear regression to identify genetic correlates of uptake. Uptake of the compound correlated with the logIC50 of chloroquine and, more weakly, a mutation in Pgh1, F1226Y.

  6. Evaluating pyrene toxicity on Arctic key copepod species Calanus hyperboreus

    DEFF Research Database (Denmark)

    Nørregaard, Rasmus Dyrmose; Nielsen, Torkel Gissel; Friis Møller, Eva

    2014-01-01

    was unaffected. The hatching success was also unaffected, although the total reproductive output was reduced with increased pyrene concentrations. Accumulation of pyrene in the copepods was higher in feeding than starving females and only trace amounts of the phase I metabolite 1-hydroxypyrene, were found...

  7. Interdependence of pyrene interactions and tetramolecular G4-DNA assembly.

    Science.gov (United States)

    Doluca, Osman; Withers, Jamie M; Loo, Trevor S; Edwards, Patrick J B; González, Carlos; Filichev, Vyacheslav V

    2015-03-28

    Controlling the arrangement of organic chromophores in supramolecular architectures is of primary importance for the development of novel functional molecules. Insertion of a twisted intercalating nucleic acid (TINA) moiety, containing phenylethynylpyren-1-yl derivatives, into a G-rich DNA sequence alters G-quadruplex folding, resulting in supramolecular structures with defined pyrene arrangements. Based on CD, NMR and ESI-mass-spectra, as well as TINA excited dimer (excimer) fluorescence emission we propose that insertion of the TINA monomer in the middle of a dTG4T sequence (i.e. dTGGXGGT, where X is TINA) converts a parallel tetramolecular G-quadruplex into an assembly composed of two identical antiparallel G-quadruplex subunits stacked via TINA-TINA interface. Kinetic analysis showed that TINA-TINA association controls complex formation in the presence of Na(+) but barely competes with guanine-mediated association in K(+) or in the sequence with the longer G-run (dTGGGXGGGT). These results demonstrate new perspectives in the design of molecular entities that can kinetically control G-quadruplex formation and show how tetramolecular G-quadruplexes can be used as a tuneable scaffold to control the arrangement of organic chromophores.

  8. Biluminescence via Fluorescence and Persistent Phosphorescence in Amorphous Organic Donor(D4)-Acceptor(A) Conjugates, and Application in Data Security Protection.

    Science.gov (United States)

    Bhatia, Harsh; Bhattacharjee, Indranil; Ray, Debdas

    2018-06-25

    Purely organic biluminescent materials are of great interest due to the involvement of both singlet and long-lived triplet emissions, which have been used in bio-imaging and organic light-emitting diodes. We show two molecules 3,4,5,6-tetraphenyloxy-phthlonitrile (POP) and 3,4,5,6-tetrakis-p-tolyloxy-phthalonitrile (TOP), in which POP was found to exhibit fluorescence and persistent room-temperature green phosphorescence (pRTGP) in the amorphous and crystal states. Both POP and TOP show aggregation induced emission in tetrahydrofuran-water mixture. We found in single crystal X-ray analysis that intra-and inter molecular lp(O)•••π interactions along with (π(C=C)•••π(C≡N), hydrogen bond (H-B), and C-H•••π interactions induce head-to-tail slipped-stacked arrangement in POP. In addition, X-ray structure of TOP with slipped-stack arrangement induced by only (π(C=C)•••π(C≡N) and H-B interactions, shows dim afterglow only in crystals. These indicate that more number of non-covalent interactions may reinforce relatively efficient inter system crossing that leads to pRTGP even in the amorphous state of POP. Given the unique green afterglow feature in amorphous state of POP, document security protection application is achievable.

  9. Quantitative determination of benzo[a]pyrene in foodstuffs using benzo[a]pyrene[G-3H

    International Nuclear Information System (INIS)

    Masuda, Yoshito; Shimamura, Kyoko; Yano, Hiroshige

    1977-01-01

    A method for quantitative determination of nano gram level of benzo(a)pyrene (BP) in foodstuffs using tritiated BP( 3 H-BP) was described. Extracts from foodstuffs, having been added a certain amount of 3 H-BP, were fractionated by column chromatography on Florisil, and thinlayer chromatography on acetylated cellulose. Concentration and radio activity of BP in the final fraction were determined by fluorescence spectrometry and liquid scintillation. Recovery ratio of each experiment was obtained by comparing the radio activities of added 3 H-BP and separated BP. Concentration of BP in the sample analyzed was calculated from the amount of isolated BP and the recovery ratio in each experiment. A quantitative limit of BP by this method was 0.2 ppb when 50 g of sample was used. By this method, contents of BO in each sample of Tenpura oil, salad oil, flour, and polished rice were determined as 0.6, 0.2, 0.1 and < 0.1 ppb on average, respectively. (auth.)

  10. Synthesis of polycyclic aromatic hydrocarbon-protein conjugates for preparation and immunoassay of antibodies.

    Science.gov (United States)

    Glushkov, Andrey N; Kostyanko, Mikhail V; Cherno, Sergey V; Vasilchenko, Ilya L

    2002-04-01

    The method is described dealing with the synthesis of conjugates protein-polycyclic aromatic hydrocarbons (PAHs), highly soluble in water, stable without special stabilizers and containing the minimum quantity of cross-linked products. The reaction of protein with PAH containing an aldehyde group, has been carried out in an alkaline solution, and stabilization of the conjugate has been achieved by reduction with sodium borohydride in the presence of a compound blocking the formation of an insoluble polymeric fraction. The efficiency of synthesized conjugates for the induction and immunoassay of Abs to PAH for benzo[a]pyrene is shown.

  11. Photophysical and computational investigation of the intermolecular interactions of pyrene with phenothiazine and promazine

    Energy Technology Data Exchange (ETDEWEB)

    Güloğlu, Pınar; Acar, Nursel, E-mail: nursel.acar@ege.edu.tr

    2016-10-20

    Highlights: • Intermolecular interactions of pyrene with phenothiazine/promazine were investigated. • All investigated systems were optimized at ωB97XD/6-31G(d,p) level in gas phase. • The electronic transitions were determined using frontier orbitals. • Both Py–Pheno and Py–Prom are potential candidates for charge transfer systems. - Abstract: The intermolecular interactions between the pyrene (Py) (as acceptor) and phenothiazine (Pheno), promazine (Prom) (as donors) were investigated using UV/Vis absorption and fluorescence spectroscopy. Fluorescence quenching rate constants for Py–Pheno and Py–Prom systems have been calculated approximately 10{sup 10} M{sup −1} s{sup −1}, indicating diffusion controlled processes. A computational investigation has also been carried out in gas phase at ωB97XD/6-31G(d,p) level. Time-dependent density functional theory (TDDFT) was used to calculate the electronic transitions of molecules at B3LYP/6-311++G(d,p) level. Total electronic energies, complexation energies, free energy differences, excitation wavelengths, and HOMO–LUMO energy gaps are discussed in gas phase. Analyses of first excited singlet states have indicated charge transfers transitions between Py and Pheno, Prom through π–π stacking in gas phase at 433 nm and 466 nm, respectively. Due to its charge transfer character, Py–Pheno and Py–Prom systems seem to be appropriate models to investigate and design photosensitive materials.

  12. Immobilization and stretching of 5'-pyrene-terminated DNA on carbon film deposited on electron microscope grid.

    Science.gov (United States)

    Loukanov, Alexandre; Filipov, Chavdar; Lecheva, Marta; Emin, Saim

    2015-11-01

    The immobilization and stretching of randomly coiled DNA molecules on hydrophobic carbon film is a challenging microscopic technique, which possess various applications, especially for genome sequencing. In this report the pyrenyl nucleus is used as an anchor moiety to acquire higher affinity of double stranded DNA to the graphite surface. DNA and pyrene are joined through a linker composed of four aliphatic methylene groups. For the preparation of pyrene-terminated DNA a multifunctional phosphoramidite monomer compound was designed. It contains pyrenylbutoxy group as an anchor moiety for π-stacking attachment to the carbon film, 2-cyanoethyloxy, and diisopropylamino as coupling groups for conjugation to activated oligonucleotide chain or DNA molecule. This monomer derivative was suitable for incorporation into automated solid-phase DNA synthesis and was attached to the 5' terminus of the DNA chain through a phosphodiester linkage. The successful immobilization and stretching of pyrene-terminated DNA was demonstrated by conventional 100 kV transmission electron microscope. The microscopic analysis confirmed the stretched shape of the negatively charged nucleic acid pieces on the hydrophobic carbon film. © 2015 Wiley Periodicals, Inc.

  13. New heparin–indomethacin conjugate with an ester linkage: Synthesis, self aggregation and drug delivery behavior

    Energy Technology Data Exchange (ETDEWEB)

    Li, Nan-Nan; Zheng, Bing-Na [DSAPM Lab and PCFM Lab, Institute of Polymer Science, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Lin, Jian-Tao [DSAPM Lab and PCFM Lab, Institute of Polymer Science, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Guangdong Medical College, Dongguan 523808 (China); Zhang, Li-Ming, E-mail: ceszhlm@mail.sysu.edu.cn [DSAPM Lab and PCFM Lab, Institute of Polymer Science, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

    2014-01-01

    New heparin–indomethacin conjugate with an ester linkage was prepared by the carbodiimide-mediated condensation reaction, and then characterized by FTIR and {sup 1}HNMR analyses. Due to its amphiphilic character, such a conjugate could self-aggregate into spherical nanoparticles in aqueous system, as confirmed by fluorescence spectroscopy, dynamic light scattering and transmission electron microscopy. By the in vitro drug release tests, the resultant conjugate nanoparticles were found to have a sustained and esterase-sensitive release behavior for conjugated indomethacin. In addition, the uptake of these conjugate nanoparticles into human nasopharyngeal carcinoma CNE1 cells was confirmed by fluorescence microscopy. - Highlights: • New heparin–indomethacin conjugate with an ester linkage was prepared. • Such a conjugate could self-aggregate into spherical nanoparticles in aqueous system. • The resultant conjugate nanoparticles exhibited an esterase-sensitive drug release behavior. • The resultant conjugate nanoparticles showed the cellular uptake ability in CNE1 cells.

  14. Effect of dietary factors on mutagenesis, metabolism, and binding to DNA of benzo[a]pyrene and benzo[a]pyrene 7,8-dihydrodiol

    International Nuclear Information System (INIS)

    Vance, R.E.

    1988-01-01

    Ellagic acid (EA), a naturally occurring plant phenol, at concentrations of 5 to 50 μg/plate, inhibited rate liver S9 protein dependent benzo[a]pyrene (B[a]P)-induced mutagenesis in Salmonella typhimurium TA 100 by 30-81% and B[a]P 7,8-dihydrodiol (DHD)-induced mutagenesis by 29 to 75%. EA did not significantly affect the metabolism of B[a]P or B[a]P 7,8-DHD as determined by high performance liquid chromatographic analysis of the organosoluble fraction and by the quantification of water-soluble conjugates. At these concentrations EA inhibited the covalent binding of [ 3 H] B[a]P and [ 3 H] B[a]P 7,8-DHD metabolites to calf thymus DNA by 5 to 42% and 27 to 64%, respectively. Formation of benzo[a]pyrene 7,8-dihydrodiol-9,10-epoxide:deoxyguanosine (BPDE:dG) adducts was inhibited by 13 to 56% for B[a]P for B[a]P and 11 to 38% for B[a]P 7,8-DHD. These results suggest that the antimutagenic effect of EA and its inhibition of B[a]P and B[a]P 7,8-DHD metabolite-binding to DNA is not due to the inhibition of S9-mediated metabolism of these compounds. The inhibitory effect may be by previously described scavenging mechanism or by a DNA-affinity binding mechanism that prevents BPDE:DNA adduct formation

  15. Trophic transfer of pyrene metabolites between aquatic invertebrates

    International Nuclear Information System (INIS)

    Carrasco Navarro, V.; Leppänen, M.T.; Kukkonen, J.V.K.; Godoy Olmos, S.

    2013-01-01

    The trophic transfer of pyrene metabolites was studied using Gammarus setosus as a predator and the invertebrates Lumbriculus variegatus and Chironomus riparius as prey. The results obtained by liquid scintillation counting confirmed that the pyrene metabolites produced by the aquatic invertebrates L. variegatus and C. riparius were transferred to G. setosus through the diet. More detailed analyses by liquid chromatography discovered that two of the metabolites produced by C. riparius appeared in the chromatograms of G. setosus tissue extracts, proving their trophic transfer. These metabolites were not present in chromatograms of G. setosus exclusively exposed to pyrene. The present study supports the trophic transfer of PAH metabolites between benthic macroinvertebrates and common species of an arctic amphipod. As some PAH metabolites are more toxic than the parent compounds, the present study raises concerns about the consequences of their trophic transfer and the fate and effects of PAHs in natural environments. - Highlights: ► The trophic transfer of pyrene metabolites between invertebrates was evaluated. ► Biotransformation of pyrene by L. variegatus and C. riparius is different. ► Metabolites produced by L. variegatus and C. riparius are transferred to G. setosus. ► Specifically, two metabolites produced by C. riparius were transferred. - Some of the pyrene metabolites produced by the model invertebrates L. variegatus and C. riparius are transferred to G. setosus through the diet, proving their trophic transfer.

  16. Bioremediation of Pyrene-Contaminated Soils Using Biosurfactant

    Directory of Open Access Journals (Sweden)

    Jorfi

    2014-10-01

    Full Text Available Background Polycyclic aromatic hydrocarbons (PAHs are persistence organic chemicals with proved carcinogenic and mutagenic hazards. These compounds are usually adsorbed in soils in vicinity of oil and gas industries. Bioremediation of PAHs contaminated soils is difficult due to hydrophobic nature of PAHs. Objectives The main purpose of the current study was to determine the pyrene removal efficiency in synthetically contaminated soil, using biosurfactant. Materials and Methods Four pure bacterial strains capable of pyrene degradation were isolated from contaminated soils via enrichment techniques. The soil samples were spiked with an initial pyrene concentration of 500 mg/kg and subjected to bioremediation using a mixed culture comprised of previously isolated strains, in addition to application of biosurfactant during 63 days. Results The pyrene removal efficiency in samples containing biosurfactant, without biosurfactant and controls, were 86.4%, 59.8% and 14%, respectively, after 63 days. The difference of pyrene removal efficiency between the biosurfactant-containing samples and the ones without it was significant (P < 0.05. Conclusions Application of rhamnolipid biosurfactant produced by Pseudomonas aeruginosa significantly improved pyrene removal in contaminated soils.

  17. Progress of pyrene-based organic semiconductor in organic field effect transistors

    Institute of Scientific and Technical Information of China (English)

    Yanbin; Gong; Xuejun; Zhan; Qianqian; Li; Zhen; Li

    2016-01-01

    Thanks to the pure blue emitting, high planarity, electron rich and ease of chemical modification, pyrene has been thoroughly investigated for applications in organic electronics such as organic light emitting diodes(OLEDs), organic field effect transistors(OFETs), and organic solar cells(OSCs). Especially, great progresses have been made of pyrene-based organic semiconductors for OFETs in past decades. Due to the difference of molecular structure, pyrene-based organic semiconductors are divided into three categories, pyrene as terminal group, pyrene as center core and fused pyrene derivatives. This minireview gives a brief introduction of the structure-property relationship and application in OFETs about most of pyrene-based semiconducting materials since 2006,illustrating that pyrene is a good building block to construct semiconductors with superior transport property for OFETs. Finally, we provide a summary concerning the methodology to improve the transport property of the pyrene-based semiconducting materials as well as an outlook.

  18. Synthesis, fluorescence properties and the promising cytotoxicity of pyrene–derived aminophosphonates

    Directory of Open Access Journals (Sweden)

    Jarosław Lewkowski

    2016-06-01

    Full Text Available A large series of variously substituted amino(pyren-1-ylmethylphosphonic acid derivatives was synthesized using a modified aza-Pudovik reaction in 20–97% yields. The fluorescence properties of the obtained compounds were investigated revealing that N-alkylamino(pyren-1-ylmethylphosphonic derivatives are stronger emissive compounds than the corresponding N-aryl derivatives. N-Benzylamino(pyren-1-ylmethylphosphonic acid displayed strong fluorescence (ΦF = 0.68 in phosphate-buffered saline (PBS. The influence of a series of derivatives on two colon cancer cell lines HT29 and HCT116 was also investigated. The most promising results were obtained for N-(4-methoxyphenylamino(pyren-1-ylmethylphosphonate, which was found to be cytotoxic for the HCT116 cancer cell line (IC50 = 20.8 μM, simultaneously showing weak toxicity towards normal lymphocytes (IC50 = 230.8 µM.

  19. Synthesis, fluorescence properties and the promising cytotoxicity of pyrene–derived aminophosphonates

    Science.gov (United States)

    Rodriguez Moya, Maria; Wrona-Piotrowicz, Anna; Gajek, Gabriela

    2016-01-01

    Summary A large series of variously substituted amino(pyren-1-yl)methylphosphonic acid derivatives was synthesized using a modified aza-Pudovik reaction in 20–97% yields. The fluorescence properties of the obtained compounds were investigated revealing that N-alkylamino(pyren-1-yl)methylphosphonic derivatives are stronger emissive compounds than the corresponding N-aryl derivatives. N-Benzylamino(pyren-1-yl)methylphosphonic acid displayed strong fluorescence (ΦF = 0.68) in phosphate-buffered saline (PBS). The influence of a series of derivatives on two colon cancer cell lines HT29 and HCT116 was also investigated. The most promising results were obtained for N-(4-methoxyphenyl)amino(pyren-1-yl)methylphosphonate, which was found to be cytotoxic for the HCT116 cancer cell line (IC50 = 20.8 μM), simultaneously showing weak toxicity towards normal lymphocytes (IC50 = 230.8 µM). PMID:27559373

  20. Interaction of 1-pyrene sulfonic acid sodium salt with human serum albumin

    Energy Technology Data Exchange (ETDEWEB)

    Steblecka, Malgorzata, E-mail: gosia@mitr.p.lodz.pl; Wolszczak, Marian, E-mail: marianwo@mitr.p.lodz.pl; Szajdzinska-Pietek, Ewa, E-mail: espietek@mitr.p.lodz.pl

    2016-04-15

    Steady state and time-resolved techniques of optical spectroscopy were applied to examine the interaction between 1-pyrene sulfonic acid (PSA) sodium salt and human serum albumin (HSA). This work is directed towards finding a convenient fluorescent marker (or blocker) of hydrophobic binding sites within the protein, to be used in the in vitro studies of HSA−drug systems. The observed variation of PSA absorbance with HSA concentration was interpreted in terms of two possible probe/protein binding modes with the binding constants K{sub b,1}=(6.5±0.6)∙10{sup 6} M{sup −1} (a specific receptor site), and K{sub b,2}=(3.8±0.8)∙10{sup 5} M{sup −1} (non-specific binding of up to three probe molecules). The PSA fluorescence is quenched by the albumin (via both static and dynamic mechanisms), and also the HSA–Trp214 fluorescence is quenched by PSA (via resonance energy transfer). These results indicate that the probe is bound in the domain IIA of the secondary HSA structure. At lower [PSA]/[HSA] ratios the PSA fluorescence lifetime is longer than that in homogeneous buffer solutions (not containing HSA). Therefore, we conclude that lower affinity binding sites are distant from the tryptophan residue. This is confirmed by complementary studies on the transient T–T absorbance and on luminescence of the photosensitized singlet oxygen.

  1. Modulating the nanorods protrusion from poly(allylamine hydrochloride)-g-pyrene microcapsules by 1-pyrenesulfonic acid sodium salt.

    Science.gov (United States)

    Guan, Erjia; Wang, Tianxiang; Wang, Zhipeng; Gao, Changyou

    2013-09-01

    It was found previously that the Schiff base bonds in poly(allylamine hydrochloride)-g-pyrene (PAH-Py) microcapsules (MCs) are hydrolyzed at pH 2 within 1 h, leading to disassembly of the MCs and protrusion of pyrene aldehyde (Py) nanorods (NRs) on the capsule surface. Herein, we found a new way to modulate the protrusion of NRs by addition of 1-pyrenesulfonic acid sodium salt (PySO3Na). Along with the increase in PySO3Na to Py molar ratio in the MCs solution, the protrusion of NRs was progressively blocked and even inhibited at a ratio of 2.3, and at this condition, the microcapsules were stable under pH 2 for 24 h. After the composite microcapsules with excess PySO3Na were washed with a pH 10 solution and then incubated in a pH 2 solution, the NRs could be protruded from the MCs again. The fluorescence peak position of the PAH-Py/PySO3Na MCs gradually red-shifted with a decrease in pH value, and a sharp transition occurred at p H3.6, demonstrating the formation of pyrene excimers between the PySO3Na small molecules and the pendant Py groups on the PAH chain. The formed excimers take the role of blocking the self-assembly of cleaved Py molecules instead of inhibiting the hydrolysis of the Schiff base, whereas the MCs were stabilized by the charge interaction between PySO3Na and PAH backbone and the hydrophobic interaction between the pyrene rings. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Tetraaryl pyrenes: photophysical properties, computational studies, crystal structures, and application in OLEDs

    KAUST Repository

    El-Assaad, Tarek H.

    2015-10-15

    Pyrene was derivatized in positions 1, 3, 6, and 8 to yield a series of nine tetraarylpyrenes for which absorption, emission, emission lifetimes and solvatochromism in solution were determined. The fluorescence quantum yields in thin films and crystalline state, electrochemistry, and quantum-chemical calculations were completed for the series along with the X-ray crystal structure analysis of compounds 1, 2, 4, 5, 7, and 9. Compounds 2, 3, 4 as well as 7 were identified as the most suitable candidates for OLED application. Notably, in an unoptimized single-layer device geometry, these compounds exhibited blue electroluminescence coupled with impressively low turn-on voltages and high maximum luminances such as 2.8 V and 13 542 cd m-2 at 8.2 V for compound 2, respectively. © The Royal Society of Chemistry 2016.

  3. Tetraaryl pyrenes: photophysical properties, computational studies, crystal structures, and application in OLEDs

    KAUST Repository

    El-Assaad, Tarek H.; Auer, Manuel; Castañ eda, Raul; Hallal, Kassem M.; Jradi, Fadi M.; Mosca, Lorenzo; Khnayzer, Rony S.; Patra, Digambara; Timofeeva, Tatiana V.; Bredas, Jean-Luc; List-Kratochvil, Emil J. W.; Wex, Brigitte; Kaafarani, Bilal R.

    2015-01-01

    Pyrene was derivatized in positions 1, 3, 6, and 8 to yield a series of nine tetraarylpyrenes for which absorption, emission, emission lifetimes and solvatochromism in solution were determined. The fluorescence quantum yields in thin films and crystalline state, electrochemistry, and quantum-chemical calculations were completed for the series along with the X-ray crystal structure analysis of compounds 1, 2, 4, 5, 7, and 9. Compounds 2, 3, 4 as well as 7 were identified as the most suitable candidates for OLED application. Notably, in an unoptimized single-layer device geometry, these compounds exhibited blue electroluminescence coupled with impressively low turn-on voltages and high maximum luminances such as 2.8 V and 13 542 cd m-2 at 8.2 V for compound 2, respectively. © The Royal Society of Chemistry 2016.

  4. Investigation of benzo(a)pyrene-globin adducts

    Energy Technology Data Exchange (ETDEWEB)

    Wallin, H; Jeffre, A M; Santella, R M

    1987-05-01

    The nature of the adducts formed between benzo(a)pyrene (BP) and globin were investigated in animals treated with (/sup 3/H)BP. Modification levels on globin were determined by radioactivity measurements. Since BP tetraols can be released from benzo(a)pyrene diol epoxide modified protein and DNA by acid treatment, globin samples were treated with acid, released tetraols separated by HPLC and quantitated by scintillation counting. In addition, acid released material was measured in competitive enzyme linked immunosorbent assay (ELISA) using antibodies which recognize BP tetraols. Both measurements indicate that only 2% of bound radioactivity could be released as free BP tetraols. These studies indicate that benzo(a)pyrene diol epoxide may not be the major metabolite of BP involved in globin binding. (author). 14 refs.

  5. IRIS Toxicological Review of Benzo[a]pyrene (Interagency ...

    Science.gov (United States)

    In January 2017, EPA finalized the IRIS assessment of Benzo[a]pyrene. The Toxicological Review was reviewed internally by EPA and by other federal agencies and White House Offices before public release. Consistent with the May 2009 IRIS assessment development process, all written comments on IRIS assessments submitted by other federal agencies and White House Offices are made publicly available. Accordingly, interagency comments and the interagency science discussion materials provided to other agencies, including interagency review drafts of the IRIS Toxicological Review of Benzo[a]pyrene are posted on this site. EPA is undertaking an update of the Integrated Risk Information System (IRIS) health assessment for benzo[a]pyrene (BaP). The outcome of this project is an updated Toxicological Review and IRIS Summary for BaP that will be entered into the IRIS database.

  6. Structural design of intrinsically fluorescent oxysterols

    DEFF Research Database (Denmark)

    Nåbo, Lina J; Modzel, Maciej; Krishnan, Kathiresan

    2018-01-01

    Oxysterols are oxidized derivatives of cholesterol with many important biological functions. Trafficking of oxysterols in and between cells is not well studied, largely due to the lack of appropriate oxysterol analogs. Intrinsically fluorescent oxysterols present a new route towards direct...... observation of intracellular oxysterol trafficking by fluorescence microscopy. We characterize the fluorescence properties of the existing fluorescent 25-hydroxycholesterol analog 25-hydroxycholestatrienol, and propose a new probe with an extended conjugated system. The location of both probes inside...

  7. Biotransformering af pyren i havbørsteormen Nereis virens

    DEFF Research Database (Denmark)

    Jørgensen, Anne; Giessing, Anders; Juul Rasmussen, Lene

    føden og ved overførsel over epithelet. Graden af systemisk akkumulering af PAHer afhænger af optaget men ligeledes af effektiviteten af biotransformering i den pågældende organisme. N. virens er kendt for effektivt at biotransformere PAHer. I nærværende undersøgelse blev biotransformering undersøgt med......-glucuronid er den fase II metabolit der primært produceres ved biotransformering af pyren. Dette indikerer at de vigtigste enzymer i biotransformering af pyren i N. virens er CYP enzymer og glucuronosyl transferase enzymer....

  8. Conjugates of a Photoactivated Rhodamine with Biopolymers for Cell Staining

    Science.gov (United States)

    Zaitsev, Sergei Yu.; Shaposhnikov, Mikhail N.; Solovyeva, Daria O.; Solovyeva, Valeria V.; Rizvanov, Albert A.

    2014-01-01

    Conjugates of the photoactivated rhodamine dyes with biopolymers (proteins, polysaccharides, and nucleic acids) are important tools for microscopic investigation of biological tissue. In this study, a precursor of the photoactivated fluorescent dye (PFD) has been successfully used for staining of numerous mammalian cells lines and for conjugate formation with chitosan (“Chitosan-PFD”) and histone H1 (“Histone H1.3-PFD”). The intensive fluorescence has been observed after photoactivation of these conjugates inside cells (A431, HaCaT, HEK239, HBL-100, and MDCK). Developed procedures and obtained data are important for further application of novel precursors of fluorescent dyes (“caged” dyes) for microscopic probing of biological objects. Thus, the synthesized “Chitosan-PFD” and “Histone H1-PFD” have been successfully applied in this study for intracellular transport visualization by fluorescent microscopy. PMID:25383365

  9. Rapid quantification of polycyclic aromatic hydrocarbons in hydroxypropyl-{beta}-cyclodextrin (HPCD) soil extracts by synchronous fluorescence spectroscopy (SFS)

    Energy Technology Data Exchange (ETDEWEB)

    Guoxiong, Hua [School of Biology and Psychology, Institute for Research on Environment and Sustainability, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom); Broderick, John [School of Biology and Psychology, Institute for Research on Environment and Sustainability, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom); Semple, Kirk T [Department of Environmental Science, Faculty of Science and Technology, University of Lancaster, Lancaster LA1 4YQ (United Kingdom); Killham, Ken [School of Biological Sciences, University of Aberdeen, Aberdeen AB24 3UU (United Kingdom); Singleton, Ian [School of Biology and Psychology, Institute for Research on Environment and Sustainability, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2007-07-15

    Synchronous fluorescence spectroscopy (SFS) was directly applied to rapidly quantify selected polycyclic aromatic hydrocarbons (PAHs: benzo[a]pyrene and pyrene) in aqueous hydroxypropyl-{beta}-cyclodextrin (HPCD) soil extract solutions from a variety of aged contaminated soils containing four different PAHs. The method was optimized and validated. The results show that SFS can be used to analyse benzo[a]pyrene and pyrene in HPCD based soil extracts with high sensitivity and selectivity. The linear calibration ranges were 4.0 x 10{sup -6}-1.0 x 10{sup -3} mM for benzo[a]pyrene and 6.0 x 10{sup -6}-1.2 x 10{sup -3} mM for pyrene in 10 mM HPCD aqueous solution alone. The detection limits according to the error propagation theory for benzo[a]pyrene and pyrene were 3.9 x 10{sup -6} and 5.4 x 10{sup -6} mM, respectively. A good agreement between SFS and HPLC was reached for both determinations of PAHs in HPCD alone and in soil HPCD extracts. Hence, SFS is a potential means to simplify the present non-exhaustive hydroxypropyl-{beta}-cyclodextrin (HPCD)-based extraction technique for the evaluation of PAH bioavailability in soil. - SFS can be used to rapidly quantify selected PAHs in soil extracts and to simplify the non-exhaustive HPCD-based extraction technique for the evaluation of PAH bioavailability.

  10. Rapid quantification of polycyclic aromatic hydrocarbons in hydroxypropyl-β-cyclodextrin (HPCD) soil extracts by synchronous fluorescence spectroscopy (SFS)

    International Nuclear Information System (INIS)

    Hua Guoxiong; Broderick, John; Semple, Kirk T.; Killham, Ken; Singleton, Ian

    2007-01-01

    Synchronous fluorescence spectroscopy (SFS) was directly applied to rapidly quantify selected polycyclic aromatic hydrocarbons (PAHs: benzo[a]pyrene and pyrene) in aqueous hydroxypropyl-β-cyclodextrin (HPCD) soil extract solutions from a variety of aged contaminated soils containing four different PAHs. The method was optimized and validated. The results show that SFS can be used to analyse benzo[a]pyrene and pyrene in HPCD based soil extracts with high sensitivity and selectivity. The linear calibration ranges were 4.0 x 10 -6 -1.0 x 10 -3 mM for benzo[a]pyrene and 6.0 x 10 -6 -1.2 x 10 -3 mM for pyrene in 10 mM HPCD aqueous solution alone. The detection limits according to the error propagation theory for benzo[a]pyrene and pyrene were 3.9 x 10 -6 and 5.4 x 10 -6 mM, respectively. A good agreement between SFS and HPLC was reached for both determinations of PAHs in HPCD alone and in soil HPCD extracts. Hence, SFS is a potential means to simplify the present non-exhaustive hydroxypropyl-β-cyclodextrin (HPCD)-based extraction technique for the evaluation of PAH bioavailability in soil. - SFS can be used to rapidly quantify selected PAHs in soil extracts and to simplify the non-exhaustive HPCD-based extraction technique for the evaluation of PAH bioavailability

  11. Synthesis of block copolymers derived from N-trityl-(S)-serine and pyrene end-labeled poly(methyl methacrylate) or poly(N-isopropylacrylamide) via ATRP

    Energy Technology Data Exchange (ETDEWEB)

    Buruiana, Emil C., E-mail: emilbur@icmpp.ro [Petru Poni Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley 700487, Iasi (Romania); Podasca, Viorica; Buruiana, Tinca [Petru Poni Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley 700487, Iasi (Romania)

    2012-10-15

    A new monomer bearing N-trityl-L-serine methyl ester in structure, methacryloyloxyethyl carbamoyloxy-N-trityl methyl serine (MTS), was prepared to be further polymerized by atom transfer radical polymerization (ATRP) with pyrene-endcapped poly(methyl methacrylate) (Py-PMMA-Br) or poly(N-isopropylacrylamide) (Py-PNIPA-Br). The resulting block copolymers, poly(methyl methacrylate-block-methacryloyloxyethyl carbamoyloxy-N-trityl methyl serine) (Py-PMMA-b-PMTS) and poly(N-isopropylacrylamide-block-methacryloyloxyethyl carbamoyloxy-N-trityl methyl serine (Py-PNIPA-b-PMTS) were characterized by {sup 1}H ({sup 13}C) NMR, ultraviolet, FTIR and fluorescence spectroscopy, thermal analysis, differential scanning calorimetry (DSC), atomic force microscopy (AFM), scanning electron microscopy (SEM), and gel permeation chromatography (GPC) measurements. The chemical composition in Py-PMMA-b-PMTS was estimated from the {sup 1}H NMR analysis that indicated a ratio of the repeating units of 46:19 (MMA:MTS). For the Py-PNIPA-b-PMTS the composition rate in the copolymer was 61:25 (NIPA:MTS). Quenching of the pyrene species with N,N-diethylaniline, nitrobenzene, nitrophenol, potassium iodide, p-nitrotoluene and tetracyanoquinodimethane (TCNQ) in DMF solution excited at 348 nm was evidenced, more efficiently being nitrophenol and TCNQ. In this case, the monomer emission at 388-409 nm underwent a significant decrease caused of an electron transfer from the electron-reach photoexcited pyrene molecule to the electron-deficient quenchers. - Highlights: Black-Right-Pointing-Pointer Diblock copolymers combine the fluorescence of pyrene-PMMA (PNIPA) with the characteristics of PMTS. Black-Right-Pointing-Pointer Such copolymers could be used for nitroderivatives detecting. Black-Right-Pointing-Pointer UV/vis and fluorescence measurements give a good correlation for LCST of Py-PNIPA-Br.

  12. Naphthalene and pyrene degradation in contaminated soil as a ...

    African Journals Online (AJOL)

    The effect of soil particle size distribution and percent organic matter on the degradation rate of naphthalene and pyrene in a water medium of 7.05 ml/min at 27 ± 2oC in a soil reactor was studied. Analysis of the pattern of disappearance of these polycyclic aromatic hydrocarbons (PAHs) using various particle sizes showed ...

  13. Isothermal annealing kinetics of X-irradiated pyrene by EPR

    International Nuclear Information System (INIS)

    Partiti, C.S.M.; Pontuschka, W.M.; Fazzio, A.; Piccini, A.

    1989-07-01

    The annealing behavior of X-irradiated stable free radicals found in Pyrene (C 16 H 10 ) single crystals was studied by EPR. Two processes of thermal decay kinetics were found, both with the same activation energy (1.9±0.1) ev. (author) [pt

  14. Studies on the adsorption of naphthalene and pyrene from aqueous ...

    African Journals Online (AJOL)

    The effectiveness of dried ground orange peels in adsorbing naphthalene and pyrene from an aqueous stream has been investigated in terms of variation in concentration, adsorbent dosage, agitation time and particle size. Experimental batch data was correlated by Freundlich and Langmuir isotherm models.

  15. Bioremediation of Pyrene-Contaminated Soils Using Biosurfactant

    OpenAIRE

    Jorfi; Rezaee; Jaafarzadeh; Esrafili; Akbari; Moheb Ali

    2014-01-01

    Background Polycyclic aromatic hydrocarbons (PAHs) are persistence organic chemicals with proved carcinogenic and mutagenic hazards. These compounds are usually adsorbed in soils in vicinity of oil and gas industries. Bioremediation of PAHs contaminated soils is difficult due to hydrophobic nature of PAHs. Objectives The main purpose of the current study was to determine the pyrene removal efficiency in synthetically contaminated ...

  16. Optical observations geomagnetically conjugate to sprite-producing lightning discharges

    Directory of Open Access Journals (Sweden)

    R. A. Marshall

    2005-09-01

    Full Text Available Theoretical studies have predicted that large positive cloud-to-ground discharges can trigger a runaway avalanche process of relativistic electrons, forming a geomagnetically trapped electron beam. The beam may undergo pitch angle and energy scattering during its traverse of the Earth's magnetosphere, with a small percentage of electrons remaining in the loss cone and precipitating in the magnetically conjugate atmosphere. In particular, N2 1P and N2+1N optical emissions are expected to be observable. In July and August 2003, an attempt was made to detect these optical emissions, called "conjugate sprites", in correlation with sprite observations in Europe near . Sprite observations were made from the Observatoire du Pic du Midi (OMP in the French Pyrenées, and VLF receivers were installed in Europe to detect causative sferics and ionospheric disturbances associated with sprites. In the Southern Hemisphere conjugate region, the Wide-angle Array for Sprite Photometry (WASP was deployed at the South African Astronomical Observatory (SAAO, near Sutherland, South Africa, to observe optical emissions with a field-of-view magnetically conjugate to the Northern Hemisphere observing region. Observations at OMP revealed over 130 documented sprites, with WASP observations covering the conjugate region successfully for 30 of these events. However, no incidences of optical emissions in the conjugate hemisphere were found. Analysis of the conjugate optical data from SAAO, along with ELF energy measurements from Palmer Station, Antarctica, and charge-moment analysis, show that the lightning events during the course of this experiment likely had insufficient intensity to create a relativistic beam.

    Keywords. Ionosphere (Ionsophere-magnetosphere interactions; Ionospheric disturbances; Instruments and techniques

  17. Optical observations geomagnetically conjugate to sprite-producing lightning discharges

    Directory of Open Access Journals (Sweden)

    R. A. Marshall

    2005-09-01

    Full Text Available Theoretical studies have predicted that large positive cloud-to-ground discharges can trigger a runaway avalanche process of relativistic electrons, forming a geomagnetically trapped electron beam. The beam may undergo pitch angle and energy scattering during its traverse of the Earth's magnetosphere, with a small percentage of electrons remaining in the loss cone and precipitating in the magnetically conjugate atmosphere. In particular, N2 1P and N2+1N optical emissions are expected to be observable. In July and August 2003, an attempt was made to detect these optical emissions, called "conjugate sprites", in correlation with sprite observations in Europe near . Sprite observations were made from the Observatoire du Pic du Midi (OMP in the French Pyrenées, and VLF receivers were installed in Europe to detect causative sferics and ionospheric disturbances associated with sprites. In the Southern Hemisphere conjugate region, the Wide-angle Array for Sprite Photometry (WASP was deployed at the South African Astronomical Observatory (SAAO, near Sutherland, South Africa, to observe optical emissions with a field-of-view magnetically conjugate to the Northern Hemisphere observing region. Observations at OMP revealed over 130 documented sprites, with WASP observations covering the conjugate region successfully for 30 of these events. However, no incidences of optical emissions in the conjugate hemisphere were found. Analysis of the conjugate optical data from SAAO, along with ELF energy measurements from Palmer Station, Antarctica, and charge-moment analysis, show that the lightning events during the course of this experiment likely had insufficient intensity to create a relativistic beam. Keywords. Ionosphere (Ionsophere-magnetosphere interactions; Ionospheric disturbances; Instruments and techniques

  18. Selective Metal-Ion-Mediated Vesicle Adhesion Based on Dynamic Self-Organization of a Pyrene-Appended Glutamic Acid.

    Science.gov (United States)

    Xing, Pengyao; Wang, Yajie; Yang, Minmin; Zhang, Yimeng; Wang, Bo; Hao, Aiyou

    2016-07-13

    Vesicles with dynamic membranes provide an ideal model system for investigating biological membrane activities, whereby vesicle aggregation behaviors including adhesion, fusion, fission, and membrane contraction/extension have attracted much attention. In this work we utilize an aromatic amino acid (pyrene-appended glutamic acid, PGlu) to prepare nanovesicles that aggregate to form vesicle clusters selectively induced by Fe(3+) or Cu(2+), and the vesicles transform into irregular nano-objects when interacting with Al(3+). Vesicle clusters have better stability than pristine vesicles, which hinders the spontaneous morphological transformation from vesicles into lamellar nanosheets with long incubation period. The difference between complexation of Fe(3+) and Al(3+) with vesicles was studied by various techniques. On the basis of metal ion-vesicle interactions, this self-assembled nanovesicle system also behaves as an effective fluorescent sensor for Fe(3+) and Al(3+), which cause fluorescence quenching and enhanced excimer emission, respectively.

  19. Peptide-Driven Charge-Transfer Organogels Built from Synergetic Hydrogen Bonding and Pyrene-Naphthalenediimide Donor-Acceptor Interactions.

    Science.gov (United States)

    Bartocci, Silvia; Berrocal, José Augusto; Guarracino, Paola; Grillaud, Maxime; Franco, Lorenzo; Mba, Miriam

    2018-02-26

    The peptide-driven formation of charge transfer (CT) supramolecular gels featuring both directional hydrogen-bonding and donor-acceptor (D-A) complexation is reported. Our design consists of the coassembly of two dipeptide-chromophore conjugates, namely diphenylalanine (FF) dipeptide conveniently functionalized at the N-terminus with either a pyrene (Py-1, donor) or naphthalene diimide (NDI-1, acceptor). UV/Vis spectroscopy confirmed the formation of CT complexes. FTIR and 1 H NMR spectroscopy studies underlined the pivotal role of hydrogen bonding in the gelation process, and electronic paramagnetic resonance (EPR) measurements unraveled the advantage of preorganized CT supramolecular architectures for charge transport over solutions containing non-coassembled D and A molecular systems. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Novel β-cyclodextrin–eosin conjugates

    Directory of Open Access Journals (Sweden)

    Gábor Benkovics

    2017-03-01

    Full Text Available Eosin B (EoB and eosin Y (EoY, two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-β-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy and mass spectrometry. Preliminary spectroscopic investigations showed that the β-cyclodextrin–EoY conjugate retains both the fluorescence properties and the capability to photogenerate singlet oxygen of the unbound chromophore. In contrast, the corresponding β-cyclodextrin–EoB conjugate did not show either relevant emission or photosensitizing activity probably due to aggregation in aqueous medium, which precludes any response to light excitation.

  1. Novel β-cyclodextrin-eosin conjugates.

    Science.gov (United States)

    Benkovics, Gábor; Afonso, Damien; Darcsi, András; Béni, Szabolcs; Conoci, Sabrina; Fenyvesi, Éva; Szente, Lajos; Malanga, Milo; Sortino, Salvatore

    2017-01-01

    Eosin B (EoB) and eosin Y (EoY), two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-β-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy and mass spectrometry. Preliminary spectroscopic investigations showed that the β-cyclodextrin-EoY conjugate retains both the fluorescence properties and the capability to photogenerate singlet oxygen of the unbound chromophore. In contrast, the corresponding β-cyclodextrin-EoB conjugate did not show either relevant emission or photosensitizing activity probably due to aggregation in aqueous medium, which precludes any response to light excitation.

  2. Coumarin amide derivatives as fluorescence chemosensors for cyanide anions

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qianqian [School of Material Science and Engineering, Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022, Shandong (China); Liu, Zhiqiang [State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong (China); Cao, Duxia, E-mail: duxiacao@ujn.edu.cn [School of Material Science and Engineering, Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022, Shandong (China); Guan, Ruifang, E-mail: mse_guanrf@ujn.edu.cn [School of Material Science and Engineering, Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022, Shandong (China); Wang, Kangnan; Shan, Yanyan; Xu, Yongxiao; Ma, Lin [School of Material Science and Engineering, Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022, Shandong (China)

    2015-07-01

    Four coumarin amide derivatives with 4-methyl coumarin or pyrene as terminal group have been synthesized. Their photophysical properties and recognition properties for cyanide anions have been examined. The results indicate that the compounds can recognize cyanide anions with obvious absorption and fluorescence spectra change, at the same time, obvious color and fluorescence change can be observed by naked eye. The in situ hydrogen nuclear magnetic resonance spectra and photophysical properties change confirm that Michael additions between the chemosensors and cyanide anions take place at the 4-position of coumarin. - Highlights: • Four coumarin amide derivatives with 4-methyl coumarin or pyrene as terminal group were synthesized. • The compounds can recognize cyanide anions with obvious absorption and fluorescence spectra change. • Michael additions between the chemosensors and cyanide anions take place at the 4-position of coumarin.

  3. Development of a general methodology for labelling peptide-morpholino oligonucleotide conjugates using alkyne-azide click chemistry.

    Science.gov (United States)

    Shabanpoor, Fazel; Gait, Michael J

    2013-11-11

    We describe a general methodology for fluorescent labelling of peptide conjugates of phosphorodiamidate morpholino oligonucleotides (PMOs) by alkyne functionalization of peptides, subsequent conjugation to PMOs and labelling with a fluorescent compound (Cy5-azide). Two peptide-PMO (PPMO) examples are shown. No detrimental effect of such labelled PMOs was seen in a biological assay.

  4. A physiological toxicokinetic model for dermal absorption of waterborne pyrene by trout

    Energy Technology Data Exchange (ETDEWEB)

    Namdari, R.; Law, F.C.P. [Simon Fraser Univ., Burnaby, British Columbia (Canada)

    1995-12-31

    A physiologically-based toxicokinetic (PB-TK) model was developed to describe the disposition of pyrene in trout following a bolus injection into the dorsal aorta. In the present study, the PB-TK model was adapted for dermal absorption of waterborne pyrene by trout. A skin compartment with transdermal flux described mathematically by the permeability-area-concentration product was added to the PB-TK model to allow prediction of pyrene concentrations in target organs and blood on the basis of exposure concentration at the skin surface. Physiologically relevant parameters e.g., organ volume, blood flow rate, and tissue/blood partitioning coefficient which were derived from the model were similar to those reported in the previous publication. The dermal PB-TK model was validated by exposing the trunk of trout (400--500 g) to stagnant water containing 24 ppm pyrene in a specially designed chamber for 4 hr, 24 hr or 48 hr. The trout were sacrificed at the conclusion of pyrene exposure and the tissues analyzed for unchanged pyrene by HPLC. In separate experiments, trout were implanted with dorsal aorta cannuli before the trunks were exposed to stagnant water containing 24 ppm pyrene in the chamber for 4 hr. At specific time intervals during and after pyrene exposure, blood samples were withdrawn through the cannula and analyzed for pyrene by HPLC. The agreement between simulated and experimentally obtained values shows that this model is an appropriate tool to predict dermal absorption of waterborne pyrene by trout.

  5. Effects of oil dispersants on photodegradation of pyrene in marine water

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Yanyan [Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849 (United States); College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Fu, Jie [Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849 (United States); O’Reilly, S.E. [U.S. Department of the Interior, Gulf of Mexico OCS, Office of Environment, New Orleans, LA 70123 (United States); Zhao, Dongye, E-mail: zhaodon@auburn.edu [Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849 (United States)

    2015-04-28

    Highlights: • Oil dispersant enhances pyrene photodegradation in seawater. • Oil dispersant increases formation of superoxide radicals. • Pyrene photodegradation shows a two-stage kinetics and follows first-order rate law. • Pyrene is degraded mainly through electron transfer from excited pyrene to oxygen. • Higher ionic strength and temperature and lower HA favor pyrene photodegradation. - Abstract: This work investigated effects of a popular oil dispersant (Corexit EC9500A) on UV- or sunlight-mediated photodegradation of pyrene (a model polycyclic aromatic hydrocarbon) in seawater. The presence of 18 and 180 mg/L of the dispersant increased the first-order photodegradation rate by 5.5% and 16.7%, respectively, and reduced or ceased pyrene volatilization. By combining individual first-order rate laws for volatilization and photodegradation, we proposed an integrated kinetic model that can adequately predict the overall dissipation of pyrene from seawater. Mechanistic studies indicated that superoxide radicals played a predominant role in pyrene photodegradation, and the dispersant enhanced formation of superoxide radicals. 1-Hydroxypyrene was the main intermediate regardless of the dispersant, suggesting that electrons were transferred from excited pyrene to oxygen. In the presence of 18 mg/L of the dispersant, the photodegradation rate increased with increasing ionic strength and temperature, but decreased with increasing HA concentration, and remained independent of solution pH. The results are important in understanding roles of oil dispersants on environmental fate of persistent oil components in natural and engineered systems.

  6. Metabolism of benzo(a)pyrene and identification of the major benzo(a)pyrene-DNA adducts in cultured human colon

    DEFF Research Database (Denmark)

    Autrup, Herman; Harris, Curtis C.; Trump, Benjamin F.

    1978-01-01

    The metabolism of benzo(a)pyrene in cultured human colon has been investigated. Nontumorous colonie tissue was collected at the time of either surgery or "immediate autopsy" from patients with or without colonic cancer. After 24 hr in culture the expiants were exposed to [3H]benzo(a)pyrene for an...

  7. Feasibility of the simultaneous determination of polycyclic aromatic hydrocarbons based on two-dimensional fluorescence correlation spectroscopy

    Science.gov (United States)

    Yang, Renjie; Dong, Guimei; Sun, Xueshan; Yang, Yanrong; Yu, Yaping; Liu, Haixue; Zhang, Weiyu

    2018-02-01

    A new approach for quantitative determination of polycyclic aromatic hydrocarbons (PAHs) in environment was proposed based on two-dimensional (2D) fluorescence correlation spectroscopy in conjunction with multivariate method. 40 mixture solutions of anthracene and pyrene were prepared in the laboratory. Excitation-emission matrix (EEM) fluorescence spectra of all samples were collected. And 2D fluorescence correlation spectra were calculated under the excitation perturbation. The N-way partial least squares (N-PLS) models were developed based on 2D fluorescence correlation spectra, showing a root mean square error of calibration (RMSEC) of 3.50 μg L- 1 and root mean square error of prediction (RMSEP) of 4.42 μg L- 1 for anthracene and of 3.61 μg L- 1 and 4.29 μg L- 1 for pyrene, respectively. Also, the N-PLS models were developed for quantitative analysis of anthracene and pyrene using EEM fluorescence spectra. The RMSEC and RMSEP were 3.97 μg L- 1 and 4.63 μg L- 1 for anthracene, 4.46 μg L- 1 and 4.52 μg L- 1 for pyrene, respectively. It was found that the N-PLS model using 2D fluorescence correlation spectra could provide better results comparing with EEM fluorescence spectra because of its low RMSEC and RMSEP. The methodology proposed has the potential to be an alternative method for detection of PAHs in environment.

  8. Optical phase conjugation

    CERN Document Server

    Fisher, Robert A

    1983-01-01

    This book appears at a time of intense activity in optical phase conjugation. We chose not to await the maturation of the field, but instead to provide this material in time to be useful in its development. We have tried very hard to elucidate and interrelate the various nonlinear phenomena which can be used for optical phase conjugation.

  9. Dynamic changes in functional gene copy numbers and microbial communities during degradation of pyrene in soils

    International Nuclear Information System (INIS)

    Peng Jingjing; Cai Chao; Qiao Min; Li Hong; Zhu Yongguan

    2010-01-01

    This study investigates the dynamics of pyrene degradation rates, microbial communities, and functional gene copy numbers during the incubation of pyrene-spiked soils. Spiking pyrene to the soil was found to have negligible effects on the bacterial community present. Our results demonstrated that there was a significant difference in nidA gene copy numbers between sampling dates in QZ soil. Mycobacterium 16S rDNA clone libraries showed that more than 90% mycobacteria detected were closely related to fast-growing PAH-degrading Mycobacterium in pyrene-spiked soil, while other sequences related to slow-growing Mycobacterium were only detected in the control soil. It is suggested that nidA gene copy number and fast-growing PAH-degrading Mycobacterium could be used as indicators to predict pyrene contamination and its degradation activity in soils. - nidA gene and fast-growing PAH-degrading Mycobacterium can serve as indicators for pyrene contamination.

  10. Reduced cytochrome P4501A activity and recovery from oxidative stress during subchronic benzo[a]pyrene and benzo[e]pyrene treatment of rainbow trout

    International Nuclear Information System (INIS)

    Curtis, Lawrence R.; Garzon, Claudia B.; Arkoosh, Mary; Collier, Tracy; Myers, Mark S.; Buzitis, Jon; Hahn, Mark E.

    2011-01-01

    This study assessed the role of aryl hydrocarbon receptor (AHR) affinity, and cytochrome P4501A (CYP1A) protein and activity in polyaromatic hydrocarbon (PAH)-induced oxidative stress. In the 1-100 nM concentration range benzo[a]pyrene (BaP) but not benzo[e]pyrene (BeP) competitively displaced 2 nM [ 3 H]2, 3, 7, 8-tetrachloro-dibenzo-p-dioxin from rainbow trout AHR2α. Based on appearance of fluorescent aromatic compounds in bile over 3, 7, 14, 28 or 50 days of feeding 3 μg of BaP or BeP/g fish/day, rainbow trout liver readily excreted these polyaromatic hydrocarbons (PAHs) and their metabolites at near steady state rates. CYP1A proteins catalyzed more than 98% of ethoxyresorufin-O-deethylase (EROD) activity in rainbow trout hepatic microsomes. EROD activity of hepatic microsomes initially increased and then decreased to control activities after 50 days of feeding both PAHs. Immunohistochemistry of liver confirmed CYP1A protein increased in fish fed both PAHs after 3 days and remained elevated for up to 28 days. Neither BaP nor BeP increased hepatic DNA adduct concentrations at any time up to 50 days of feeding these PAHs. Comet assays of blood cells demonstrated marked DNA damage after 14 days of feeding both PAHs that was not significant after 50 days. There was a strong positive correlation between hepatic EROD activity and DNA damage in blood cells over time for both PAHs. Neither CYP1A protein nor 3-nitrotyrosine (a biomarker for oxidative stress) immunostaining in trunk kidney were significantly altered by BaP or BeP after 3, 7, 14, or 28 days. There was no clear association between AHR2α affinity and BaP and BeP-induced oxidative stress. - Highlights: → No direct association between aryl hydrocarbon receptor affinity and polyaromatic hydrocarbon induced oxidative stress. → There was a strong correlation between cytochrome P4501A activity and oxidative stress as measured with the comet assay. → There was no correlation between cytochrome P4501A

  11. Influence of chain length of pyrene fatty acids on their uptake and metabolism by Epstein-Barr-virus-transformed lymphoid cell lines from a patient with multisystemic lipid storage myopathy and from control subjects.

    Science.gov (United States)

    Radom, J; Salvayre, R; Levade, T; Douste-Blazy, L

    1990-01-01

    The uptake and intracellular metabolism of 4-(1-pyrene)butanoic acid (P4), 10-(1-pyrene)decanoic acid (P10) and 12-(1-pyrene)dodecanoic acid (P12) were investigated in cultured lymphoid cell lines from normal individuals and from a patient with multisystemic lipid storage myopathy (MLSM). The cellular uptake was shown to be dependent on the fatty-acid chain length, but no significant difference in the uptake of pyrene fatty acids was observed between MLSM and control lymphoid cells. After incubation for 1 h the distribution of fluorescent fatty acids taken up by the lymphoid cell lines also differed with the chain length, most of the fluorescence being associated with phospholipid and triacylglycerols. In contrast with P10 and P12, P4 was not incorporated into neutral lipids. When the cells were incubated for 24 h with the pyrene fatty acids, the amount of fluorescent lipids synthesized by the cells was proportional to the fatty acid concentration in the culture medium. After a 24 h incubation in the presence of P10 or P12, at any concentration, the fluorescent triacylglycerol content of MLSM cells was 2-5-fold higher than that of control cells. Concentrations of pyrene fatty acids higher than 40 microM seemed to be more toxic for mutant cells than for control cells. This cytotoxicity was dependent on the fluorescent-fatty-acid chain length (P12 greater than P10 greater than P4). Pulse-chase experiments permitted one to demonstrate the defect in the degradation of endogenously biosynthesized triacylglycerols in MLSM cells (residual activity was around 10-25% of controls on the basis of half-lives and initial rates of P10- or P12-labelled-triacylglycerol catabolism); MLSM lymphoid cells exhibited a mild phenotypic expression of the lipid storage (less severe than that observed in fibroblasts). P4 was not utilized in the synthesis of triacylglycerols, and thus did not accumulate in MLSM cells: this suggests that natural short-chain fatty acids might induce a lesser

  12. A nanodiamond-fluorescein conjugate for cell studies

    Science.gov (United States)

    Pedroso-Santana, Seidy; Fleitas-Salazar, Noralvis; Sarabia-Sainz, Andrei; Silva-Campa, Erika; Burgara-Estrella, Alexel; Angulo-Molina, Aracely; Melendrez, Rodrigo; Pedroza-Montero, Martin; Riera, Raul

    2018-03-01

    The use of nanodiamonds in studies with living systems generally involves the modification of their surfaces with functional groups. Fluorescent molecules can be attached to these groups, so that one can know the exact position of the particles in each moment of the interaction with the cells. Here we modify the surface of detonation nanodiamonds and nitrogen-vacancy center nanodiamonds using carboxylation and hydroxylation procedures. Subsequent reactions with silicates and cysteine, before addition of fluorescein allow to obtain fluorescent nano-conjugates. We used confocal microscopy to observe the position of nanodiamonds interacting with HeLa cells. At 3 h post-incubation the green fluorescence is localized in extracellular rounded like-vesicles assemblies while at 24 h the conjugates can be observed inside the cells. The measurement of the fluorescence emitted by both conjugates allowed to find an enhanced emission of fluorescein isothiocyanate (FITC) when the nitrogen-vacancy center is present. We propose the existence of a fluorescence enhancement by electron transference process. The procedure described in this work allows the functionalization of nanodiamonds with FITC and other molecules using functional surface groups and small size mediators. Also, as was proved in our work, the nanodiamond-fluorescein conjugates can be used to track nanoparticles position within the cell. Localization studies are particularly important for drug delivery applications of nanodiamonds.

  13. Multiphoton spectral analysis of benzo[a]pyrene uptake and metabolism in a rat liver cell line

    International Nuclear Information System (INIS)

    Barhoumi, Rola; Mouneimne, Youssef; Ramos, Ernesto; Morisseau, Christophe; Hammock, Bruce D.; Safe, Stephen; Parrish, Alan R.; Burghardt, Robert C.

    2011-01-01

    Dynamic analysis of the uptake and metabolism of polycyclic aromatic hydrocarbons (PAHs) and their metabolites within live cells in real time has the potential to provide novel insights into genotoxic and non-genotoxic mechanisms of cellular injury caused by PAHs. The present work, combining the use of metabolite spectra generated from metabolite standards using multiphoton spectral analysis and an 'advanced unmixing process', identifies and quantifies the uptake, partitioning, and metabolite formation of one of the most important PAHs (benzo[a]pyrene, BaP) in viable cultured rat liver cells over a period of 24 h. The application of the advanced unmixing process resulted in the simultaneous identification of 8 metabolites in live cells at any single time. The accuracy of this unmixing process was verified using specific microsomal epoxide hydrolase inhibitors, glucuronidation and sulfation inhibitors as well as several mixtures of metabolite standards. Our findings prove that the two-photon microscopy imaging surpasses the conventional fluorescence imaging techniques and the unmixing process is a mathematical technique that seems applicable to the analysis of BaP metabolites in living cells especially for analysis of changes of the ultimate carcinogen benzo[a]pyrene-r-7,t-8-dihydrodiol-t-9,10-epoxide. Therefore, the combination of the two-photon acquisition with the unmixing process should provide important insights into the cellular and molecular mechanisms by which BaP and other PAHs alter cellular homeostasis.

  14. Synthesis of block copolymers derived from N-trityl-(S)-serine and pyrene end-labeled poly(methyl methacrylate) or poly(N-isopropylacrylamide) via ATRP

    International Nuclear Information System (INIS)

    Buruiana, Emil C.; Podasca, Viorica; Buruiana, Tinca

    2012-01-01

    A new monomer bearing N-trityl-L-serine methyl ester in structure, methacryloyloxyethyl carbamoyloxy–N-trityl methyl serine (MTS), was prepared to be further polymerized by atom transfer radical polymerization (ATRP) with pyrene-endcapped poly(methyl methacrylate) (Py–PMMA–Br) or poly(N-isopropylacrylamide) (Py–PNIPA–Br). The resulting block copolymers, poly(methyl methacrylate–block–methacryloyloxyethyl carbamoyloxy–N-trityl methyl serine) (Py–PMMA–b–PMTS) and poly(N-isopropylacrylamide–block–methacryloyloxyethyl carbamoyloxy–N-trityl methyl serine (Py–PNIPA–b–PMTS) were characterized by 1 H ( 13 C) NMR, ultraviolet, FTIR and fluorescence spectroscopy, thermal analysis, differential scanning calorimetry (DSC), atomic force microscopy (AFM), scanning electron microscopy (SEM), and gel permeation chromatography (GPC) measurements. The chemical composition in Py–PMMA–b–PMTS was estimated from the 1 H NMR analysis that indicated a ratio of the repeating units of 46:19 (MMA:MTS). For the Py–PNIPA–b–PMTS the composition rate in the copolymer was 61:25 (NIPA:MTS). Quenching of the pyrene species with N,N-diethylaniline, nitrobenzene, nitrophenol, potassium iodide, p-nitrotoluene and tetracyanoquinodimethane (TCNQ) in DMF solution excited at 348 nm was evidenced, more efficiently being nitrophenol and TCNQ. In this case, the monomer emission at 388–409 nm underwent a significant decrease caused of an electron transfer from the electron-reach photoexcited pyrene molecule to the electron-deficient quenchers. - Highlights: ► Diblock copolymers combine the fluorescence of pyrene–PMMA (PNIPA) with the characteristics of PMTS. ► Such copolymers could be used for nitroderivatives detecting. ► UV/vis and fluorescence measurements give a good correlation for LCST of Py–PNIPA–Br.

  15. Effects of shape, size, and pyrene doping on electronic properties of graphene nanoflakes.

    Science.gov (United States)

    Kuamit, Thanawit; Ratanasak, Manussada; Rungnim, Chompoonut; Parasuk, Vudhichai

    2017-11-25

    Effects of size, shape, and pyrene doping on electronic properties of graphene nanoflakes (GNFs) were theoretically investigated using density functional theory method with PBE, B3PW91, and M06-2X functionals and cc-pVDZ basis set. Two shapes of zigzag GNFs, hexagonal (HGN) and rhomboidal (RGN), were considered. The energy band gap of GNF depends on shape and decreases with size. The HGN has larger band gap energy (1.23-3.96 eV) than the RGN (0.13-2.12 eV). The doping of pyrene and pyrene derivatives on both HGN and RGN was also studied. The adsorption energy of pyrene and pyrene derivatives on GNF does not depend on the shape of GNFs with energies between 21 and 27 kcal mol -1 . The substituent on pyrene enhances the binding to GNF but the strength does not depend on electron withdrawing or donating capability. The doping by pyrene and pyrene derivatives also shifts the HOMO and LUMO energies of GNFs. Both positive (destabilizing) and negative (stabilizing) shifts on HOMO and LUMO of GNFs were seen. The direction and magnitude of the shift do not follow the electron withdrawing and donating capability of pyrene substituents. However, only a slight shift was observed for doped RGN. A shift of 0.19 eV was noticed for HOMO of HGN doped with 1-aminopyrene (pyNH 2 ) and of 0.04 eV for LUMO of HGN doped with 1-pyrenecarboxylic acid (pyCOOH). Graphical Abstract HOMO and LUMO Energies of pyrene/pyrene derivatives doped Graphene Nanoflakes.

  16. Qualidade conjugal: mapeando conceitos

    Directory of Open Access Journals (Sweden)

    Clarisse Mosmann

    2006-12-01

    Full Text Available Apesar da ampla utilização do conceito de qualidade conjugal, identifica-se falta de clareza conceitual acerca das variáveis que o compõem. Esse artigo apresenta revisão da literatura na área com o objetivo de mapear o conceito de qualidade conjugal. Foram analisadas sete principais teorias sobre o tema: Troca Social, Comportamental, Apego, Teoria da Crise, Interacionismo Simbólico. Pelos postulados propostos nas diferentes teorias, podem-se identificar três grupos de variáveis fundamentais na definição da qualidade conjugal: recursos pessoais dos cônjuges, contexto de inserção do casal e processos adaptativos. Neste sentido, a qualidade conjugal é resultado do processo dinâmico e interativo do casal, razão deste caráter multidimensional.

  17. Conjugate Gaze Palsies

    Science.gov (United States)

    ... version Home Brain, Spinal Cord, and Nerve Disorders Cranial Nerve Disorders Conjugate Gaze Palsies Horizontal gaze palsy Vertical ... Version. DOCTORS: Click here for the Professional Version Cranial Nerve Disorders Overview of the Cranial Nerves Internuclear Ophthalmoplegia ...

  18. Conjugated Polymer Solar Cells

    National Research Council Canada - National Science Library

    Paraschuk, Dmitry Y

    2006-01-01

    This report results from a contract tasking Moscow State University as follows: Conjugated polymers are promising materials for many photonics applications, in particular, for photovoltaic and solar cell devices...

  19. Polymers for Protein Conjugation

    Directory of Open Access Journals (Sweden)

    Gianfranco Pasut

    2014-01-01

    Full Text Available Polyethylene glycol (PEG at the moment is considered the leading polymer for protein conjugation in view of its unique properties, as well as to its low toxicity in humans, qualities which have been confirmed by its extensive use in clinical practice. Other polymers that are safe, biodegradable and custom-designed have, nevertheless, also been investigated as potential candidates for protein conjugation. This review will focus on natural polymers and synthetic linear polymers that have been used for protein delivery and the results associated with their use. Genetic fusion approaches for the preparation of protein-polypeptide conjugates will be also reviewed and compared with the best known chemical conjugation ones.

  20. Can pyrene probes be used to measure lateral pressure profiles of lipid membranes? Perspective through atomistic simulations

    DEFF Research Database (Denmark)

    Franova, M. D.; Vattulainen, I.; Ollila, O. H. S.

    2014-01-01

    The lateral pressure profile of lipid bilayers has gained a lot of attention, since changes in the pressure profile have been suggested to shift the membrane protein conformational equilibrium. This relation has been mostly studied with theoretical methods, especially with molecular dynamics....../monomer fluorescence ratio has been assumed to represent the lateral pressure in the location of the pyrene moieties. Here, we consider the validity of this assumption through atomistic molecular dynamics simulations in a DOPC (dioleoylphosphatidylcholine) membrane, which hosts di-pyr-PC probes with different acyl...... simulations, since established methods to measure the lateral pressure profile experimentally have not been available. The only experiments that have attempted to gauge the lateral pressure profile have been done by using di-pyrenyl-phosphatidylcholine (di-pyr-PC) probes. In these experiments, the excimer...

  1. The nature of conducting materials by anodic coupling of pyrene

    Energy Technology Data Exchange (ETDEWEB)

    Zotti, G.; Schiavon, G. (Ist. di Polarografia ed Elettrochimica Preparativa, Consiglio Nazionale delle Ricerche, Padua (Italy))

    1992-05-01

    Polypyrenes from anodic coupling of pyrene in acetonitrile and 1,2-dichloroethane have been identified as the 1,1'-coupled dimer and tetramer, respectively, on the basis of electrochemical analysis and IR, UV-Vis and mass spectroscopies. Bipyrene and tetrapyrene are reversibly reduced at -2.27 and -2.15 V versus Ag/Ag{sup +}, respectively. Their electrochemical oxidation (at 0.96 and 0.87 V) is followed by further polymerization and ultimate degradation whereas iodine doping of tetrapyrene leads reversibly to a conducting adduct (6x10{sup -3} S/cm). (orig.).

  2. Baseline levels of benzo(a)pyrene in southern California mussels

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, B P [Univ. of British Columbia, Vancouver; Young, D R

    1976-12-01

    Marine mussels accumulate the carcinogen benzo(a)-pyrene from contaminated environments. Baseline studies in California indicate that levels of the carcinogen in mussels are at or near zero, except in areas of human activity. This finding runs counter to previous suggestions that benzo(a)pyrene is widely distributed in marine organisms.

  3. Pyrene removal from contaminated soil using electrokinetic process combined with surfactant

    Directory of Open Access Journals (Sweden)

    Seyed Enayat Hashemi

    2015-07-01

    Full Text Available Background: Pyrene is one of the stable polycyclic aromatic hydrocarbons that is considered as an important pollutants, because of extensive distribution in the environment and carcinogenic and mutagenic properties. Among the various treatment techniques, electrokinetic method is an environmental- friendly process for organic and mineral pollutants adsorbed to soil with fine pore size the same as clay and low hydraulic conductivity soils. For improving the efficiency of pyrene removal from soil, soulobilization of pyrene from soil could be used by surfactants. Materials and Methods : In this study, clay soil was selected as model because of the specific properties. Combined method using surfactant and electrokinetic was applied for pyrene removal from soil. Experiments were designed using response surface methodology (RSM, and effect of three variables includes surfactant concentration, voltage and surfactant type were evaluated for pyrene removal from contaminated soil. Results: Pyrene removal using anionic surfactants(SDS and nonionic surfactants(TX100 as a solubilizing agents has high removal efficiency. In the optimum condition with 95% confidence coefficient, utilizing mixed surfactants of sodium dodecyl sulfate and triton X-100 with the same volume, induced of 18.54 volt and 6.53 percent surfactant concentration have 94.6% pyrene removal efficiency. Conclusion:: Results of this study shows that electrokinetic process combined with surfactant as solubilizing agent could be applied as an efficient method for treating the pyrene-contaminated soils.

  4. The endophytic bacterium Serratia sp. PW7 degrades pyrene in wheat.

    Science.gov (United States)

    Zhu, Xuezhu; Wang, Wanqing; Crowley, David E; Sun, Kai; Hao, Shupeng; Waigi, Michael Gatheru; Gao, Yanzheng

    2017-03-01

    This research was conducted to isolate polycyclic aromatic hydrocarbon-degrading (PAH-degrading) endophytic bacteria and investigate their potential in protecting plants against PAH contamination. Pyrene-degrading endophytic bacteria were isolated from plants grown in PAH-contaminated soil. Among these endophytic bacteria, strain PW7 (Serratia sp.) isolated from Plantago asiatica was selected to investigate the suppression of pyrene accumulation in Triticum aestivum L. In the in vitro tests, strain PW7 degraded 51.2% of the pyrene in the media within 14 days. The optimal biodegradation conditions were pH 7.0, 30 °C, and MS medium supplemented with additional glucose, maltose, sucrose, and peptones. In the in vivo tests, strain PW7 successfully colonized the roots and shoots of inoculated (E + ) wheat plants, and its colonization decreased pyrene accumulation and pyrene transportation from roots to shoots. Remarkably, the concentration of pyrene in shoots decreased much more than that in roots, suggesting that strain PW7 has the potential for protecting wheat against pyrene contamination and mitigating the threat of pyrene to human health via food consumption.

  5. Bioavailability and toxicity of pyrene in soils upon biochar and compost addition.

    Science.gov (United States)

    Bielská, Lucie; Kah, Melanie; Sigmund, Gabriel; Hofmann, Thilo; Höss, Sebastian

    2017-10-01

    The study investigates the role of biochar and/or compost in mitigating the toxic effects of pyrene in soils using reproduction of nematodes and porewater concentration as measures of pyrene toxicity and bioavailability, respectively. Two soils were spiked with increasing levels of pyrene to achieve a concentration-response relationship for the reproduction of Caenorhabditis elegans. The observed EC50 values (pyrene concentration causing 50% inhibition of reproduction) were 14mg/kg and 31mg/kg (dry mass) for these soils, corresponding to equilibrium porewater concentrations of 37μg/L and 47μg/L, respectively. Differences in organic carbon content were not sufficient to explain the variability in toxicity between the different soils. Soils causing a significant inhibition of reproduction were further amended with 10%-compost, 5%-biochar, or both, and the effects on reproduction and porewater concentration determined. Combined addition of compost and biochar was identified as the most effective strategy in reducing pyrene concentration in soil porewater, which was also partly reflected in soil toxicity. However, porewater concentrations predicted only 52% of pyrene toxicity to nematodes, pointing to particle-bound or dietary exposure pathways. Capsule: Amending pyrene-spiked soil with biochar and compost effectively reduced pyrene porewater concentrations and toxicity to nematodes, which were significantly related. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Benzo(a)pyrene diol epoxides as intermediates in nucleic acid binding in vivo and in vitro

    DEFF Research Database (Denmark)

    Weinstein, I.B.; Jeffrey, A.M.; Jennette, K.W.

    1976-01-01

    Evidence has been obtained that a specific isomer of a diol epoxide derivative of benzo(a)pyrene, (+/-)-7 beta,8alpha-dihydroxy-9alpha, 10alpha-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene, is an intermediate in the binding of benzo(a)pyrene to RNA in cultured bovine bronchial mucosa. An adduct is for...

  7. Bright and photostable push-pull pyrene dye visualizes lipid order variation between plasma and intracellular membranes.

    Science.gov (United States)

    Niko, Yosuke; Didier, Pascal; Mely, Yves; Konishi, Gen-ichi; Klymchenko, Andrey S

    2016-01-11

    Imaging lipid organization in cell membranes requires advanced fluorescent probes. Here, we show that a recently synthesized push-pull pyrene (PA), similarly to popular probe Laurdan, changes the emission maximum as a function of lipid order, but outperforms it by spectroscopic properties. In addition to red-shifted absorption compatible with common 405 nm diode laser, PA shows higher brightness and much higher photostability than Laurdan in apolar membrane environments. Moreover, PA is compatible with two-photon excitation at wavelengths >800 nm, which was successfully used for ratiometric imaging of coexisting liquid ordered and disordered phases in giant unilamellar vesicles. Fluorescence confocal microscopy in Hela cells revealed that PA efficiently stains the plasma membrane and the intracellular membranes at >20-fold lower concentrations, as compared to Laurdan. Finally, ratiometric imaging using PA reveals variation of lipid order within different cellular compartments: plasma membranes are close to liquid ordered phase of model membranes composed of sphingomyelin and cholesterol, while intracellular membranes are much less ordered, matching well membranes composed of unsaturated phospholipids without cholesterol. These differences in the lipid order were confirmed by fluorescence lifetime imaging (FLIM) at the blue edge of PA emission band. PA probe constitutes thus a new powerful tool for biomembrane research.

  8. Synthesis and characterization of a fluorescent water-soluble paclitaxel prodrug.

    Science.gov (United States)

    Sohn, Jeong-Sun; Choi, Eun-Sun; Jo, Byung-Wook; Hess, Michael; Han, Song-Hee

    2010-05-01

    A fluorescence susceptible water-soluble paclitaxel was synthesized by a condensation reaction between PEGylated paclitaxel (namely, PP7) and 1-pyrene butyric acid (PBA) in order to obtain a better understanding of the mechanism of action of paclitaxel as well as of the environment of the paclitaxel-binding site. The reaction was performed successfully and the resulting paclitaxel was characterized by FT-NMR, analytical-HPLC, UV spectro photometry, and fluorescence spectrometry. The synthesized paclitaxel analogue showed a high susceptibility to fluorescence in both excitation and emission spectra. And we have investigated the time-resolved fluorescence behavior of them in different solvents and at different excitation wavelengths.

  9. Synthesis and photophysical properties of pyrene-functionalized nano-SiO{sub 2} hybrids in solutions and doped-PMMA thin films

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wen-Jie; He, Wen-Li; Yu, Hong-Yu [Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433 (China); Huang, Hong-Xiang [State Key Laboratory of Molecular Engineering of Polymers, Fudan University, 220 Handan Road, Shanghai 200433 (China); Chen, Meng [Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433 (China); Qian, Dong-Jin, E-mail: djqian@fudan.edu.cn [Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433 (China)

    2017-01-15

    Luminescent pyrene-functionalized nano-SiO{sub 2} (nano-SiO{sub 2}Pyr) hybrids were synthesized and characterized using thermogravimetry, infrared, UV–vis absorption and, X-ray photoelectron spectroscopy, as well as field emission transmission electron microscopy (FETEM). The organic substituents immobilized on the nano-SiO{sub 2}Pyr hybrids accounted for approximately 10% of the total weight. Polyethylene glycol 200 (PEG200) was found to be the most suitable solvent to suspend the nano-SiO{sub 2}Pyr hybrids compared to other commonly used organic solvents. FETEM images indicated an average SiO{sub 2} nanoparticle diameter of approximately 12 nm and a 1- to 2-nm thick organic species functionalization layer. Several emission peaks were recorded at wavelengths of 380–580 nm and were designated as emissions arising from either the monomer or excimer of the pyrene substituents. Excimer formation was concentration and solvent polarity dependent, with higher concentrations and a stronger solvent polarity benefiting excimer formation. Further, nano-SiO{sub 2}Pyr hybrids were doped in poly(methyl methacrylate) (PMMA) thin films; fluorescence spectra indicated that the excimer could be formed almost exclusively from neighboring nano-SiO{sub 2}Pyr hybrids. Time-resolved fluorescence decays revealed that the emission lifetimes of nano-SiO{sub 2}Pyr monomers and excimers were approximately 190 ns and 65–100 ns in the PEG200 solution, respectively, which was shortened to 0.45 ns to tens of ns in doped PMMA thin films, depending on the nano-hybrid concentration. Thus, the present study not only provides a method to prepare luminescent nano-materials but also a route to investigate excimer formation in solutions and thin films. - Highlights: • Luminescent pyrene-functionalized nano-SiO{sub 2}Pyr hybrids were prepared. • A 1- to 2- nm thick organic functionalization layer on nano-SiO{sub 2} was observed. • Formation of pyrene excimer was concentration and solvent

  10. Molecules for Fluorescence Detection of Specific Chemicals

    Science.gov (United States)

    Fedor, Steve

    2008-01-01

    A family of fluorescent dye molecules has been developed for use in on-off fluorescence detection of specific chemicals. By themselves, these molecules do not fluoresce. However, when exposed to certain chemical analytes in liquid or vapor forms, they do fluoresce (see figure). These compounds are amenable to fixation on or in a variety of substrates for use in fluorescence-based detection devices: they can be chemically modified to anchor them to porous or non-porous solid supports or can be incorporated into polymer films. Potential applications for these compounds include detection of chemical warfare agents, sensing of acidity or alkalinity, and fluorescent tagging of proteins in pharmaceutical research and development. These molecules could also be exploited for use as two-photon materials for photodynamic therapy in the treatment of certain cancers and other diseases. A molecule in this family consists of a fluorescent core (such as an anthracene or pyrene) attached to two end groups that, when the dye is excited by absorption of light, transfer an electron to the core, thereby quenching the fluorescence. The end groups can be engineered so that they react chemically with certain analytes. Upon reaction, electrons on the end groups are no longer available for transfer to the core and, consequently, the fluorescence from the core is no longer quenched. The chemoselectivity of these molecules can be changed by changing the end groups. For example, aniline end groups afford a capability for sensing acids or acid halides (including those contained in chemical warfare agents). Pyridine or bipyridyl end groups would enable sensing of metal ions. Other chemicals that can be selectively detected through suitable choice of end groups include glucose and proteins. Moreover, the fluorescent cores can be changed to alter light-absorption and -emission characteristics: anthracene cores fluoresce at wavelengths around 500 nm, whereas perylene cores absorb and emit at

  11. Measurement of urinary Benzo[a]pyrene tetrols and their relationship to other polycyclic aromatic hydrocarbon metabolites and cotinine in humans.

    Science.gov (United States)

    Hilton, Donald C; Trinidad, Debra A; Hubbard, Kendra; Li, Zheng; Sjödin, Andreas

    2017-12-01

    Biomonitoring of exposure to polycyclic aromatic hydrocarbons (PAHs) typically uses measurement of metabolites of PAHs with four or less aromatic rings, such as 1-hydroxypyrene, even though interest may be in exposure to larger and carcinogenic PAHs, such as benzo[a]pyrene (B[a]P). An improved procedure for measuring two tetrol metabolites of B[a]P has been developed. Using 2 mL urine, the method includes enzymatic deconjugation of the tetrol conjugates, liquid-liquid extraction, activated carbon solid phase extraction (SPE) and Strata-X SPE, and gas chromatography-electron capture negative ionization-tandem mass spectrometric determination. Limits of detection were 0.026 pg/mL (benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydrotetrol, BPT I-1) and 0.090 pg/mL (benzo[a]pyrene-r-7,t-8,c-9,c-10-tetrahydrotetrol, BPT II-1). We quantified BPT I-1 and BPT II-1 in urine from a volunteer who consumed one meal containing high levels of PAHs (barbequed chicken). We also measured urinary concentrations of BPT I-1 and BPT II-1 in smokers and nonsmokers, and compared these concentrations with those of monohydroxy PAHs (OH-PAHs) and cotinine. Urinary elimination of BPT I-1 and BPT II-1 as a function of time after dietary exposure was similar to that observed previously for OH-PAHs. While the median BPT I-1 concentration in smokers' urine (0.069 pg/mL) significantly differs from nonsmokers (0.043 pg/mL), BPT I-1 is only weakly correlated with cotinine. The urinary concentration of BPT I-1 shows a weaker relationship to tobacco smoke than metabolites of smaller PAHs, suggesting that other routes of exposure such as for example dietary routes may be of larger quantitative importance. Published by Elsevier Ltd.

  12. Polymer solar cells based on poly(3-hexylthiophene) and fullerene: Pyrene acceptor systems

    Energy Technology Data Exchange (ETDEWEB)

    Cominetti, Alessandra; Pellegrino, Andrea; Longo, Luca [Research Center for Renewable Energies and Environment, Istituto Donegani, Eni S.p.A, Via Fauser 4, IT-28100 Novara (Italy); Po, Riccardo, E-mail: riccardo.po@eni.com [Research Center for Renewable Energies and Environment, Istituto Donegani, Eni S.p.A, Via Fauser 4, IT-28100 Novara (Italy); Tacca, Alessandra; Carbonera, Chiara; Salvalaggio, Mario [Research Center for Renewable Energies and Environment, Istituto Donegani, Eni S.p.A, Via Fauser 4, IT-28100 Novara (Italy); Baldrighi, Michele; Meille, Stefano Valdo [Dipartimento di Chimica, Materiali e Ingegneria Chimica “G. Natta”, Politecnico di Milano, via Mancinelli 7, IT-20131 Milano (Italy)

    2015-06-01

    The replacement of widely used fullerene derivatives, e.g. [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), with unfunctionalized C60 and C70 is an effective approach to reduce the costs of organic photovoltaics. However, solubility issues of these compounds have always represented an obstacle to their use. In this study, bulk-heterojunction solar cells made of poly(3-hexylthiophene) donor polymer, C60 or C70 acceptors and a pyrene derivative (1-pyrenebutiric acid butyl ester) are reported. Butyl 1-pyrenebutirate limits the aggregation of fullerenes and improves the active layer morphology, plausibly due to the formation of pyrene-fullerene complexes which, in the case of pyrene-C70, were also obtained in a crystalline form. Maximum power conversion efficiencies of 1.54% and 2.50% have been obtained using, respectively, C60 or C70 as acceptor. Quantum mechanical modeling provides additional insight into the formation of plausible supermolecular structures via π-π interactions and on the redox behaviour of pyrene-fullerene systems. - Highlights: • Pyrene derivatives favour the dispersion of unfunctionalized fullerenes. • Polymer solar cells with pyrene: C60 adduct as acceptor have efficiencies of 1.54%. • When C60 is substituted with C70 the efficiency is increased to 2.50%. • DFT calculations support the plausibility of the formation of pyrene: fullerene adducts. • The use of unfunctionalized fullerenes may decrease the costs of polymer solar cells.

  13. Fluorescence spectroscopy

    DEFF Research Database (Denmark)

    Bagatolli, Luis

    2016-01-01

    Fluorescence spectroscopy is a powerful experimental tool used by scientists from many disciplines. During the last decades there have been important developments on distinct fluorescence methods, particularly those related to the study of biological phenomena. This chapter discusses the foundati......Fluorescence spectroscopy is a powerful experimental tool used by scientists from many disciplines. During the last decades there have been important developments on distinct fluorescence methods, particularly those related to the study of biological phenomena. This chapter discusses...

  14. Differences in the covalent binding of benzo(a)pyrene, safrole, 1'-hydroxysafrole, and 4-aminobiphenyl to DNA of pregnant and non-pregnant mice

    International Nuclear Information System (INIS)

    Lu, L.W.; Disher, R.M.; Randerath, Kurt

    1986-01-01

    The effects of pregnancy on the covalent binding of several carcinogens to DNA were investigated in mice. Non-pregnant or timed-pregnant (18th day of gestation) ICR mice of similar age were treated with benzo(a)pyrene (BP, 200 μmol/kg), safrole (600 μmol/kg), 1'-hydroxysafrole (400 μmol/kg), 4-aminobiphenyl (4-ABP, 800 μmol/kg) or trioctanoin (4 ml/kg) per os. Tissue DNA adduct levels at 24 h after carcinogen treatment were analyzed via a 32 P-postabeling assay. Pregnancy lowered the binding of the ultimate carcinogenic metalolite of BP, 7β, 8α-dihydroxy-9, 10α-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene (BPDE I), to liver and lung DNA by 29-41%, but not the binding of other metabolites. The binding of safrole and its proximate carcinogen, 1'-hydroxysafrole, to liver and kidney DNA was increased 2.3-3.5 fold. Pregnancy decreased the binding of 4-ABP to liver DNA by approx. 18% but increased its binding to kidney DNA by 67%. The results suggest that exposure to some genotoxic compounds especially those requiring conjugation reactions for metabolic activation, may be more hazardous during pregnancy than in the non-pregnant state (author)

  15. Synthesis of Novel C-2- or C-15-Labeled BODIPY—Estrone Conjugates

    Directory of Open Access Journals (Sweden)

    Ildikó Bacsa

    2018-04-01

    Full Text Available Novel BODIPY–estrone conjugates were synthesized via Cu(I-catalyzed azide–alkyne cycloaddition (CuAAC. Estrone-alkynes or an estrone-azide as starting compounds were synthesized via Michael addition or Sonogashira reaction as key steps. Fluorescent dyes based on BODIPY-core were provided by azide or alkyne functional groups. Fluorescent labeling of estrone was efficiently achieved at the C-2 or C-15 position. The newly-elaborated coupling procedures might have a broad applicability in the synthesis of fluorescent-labeled estrone conjugates suitable for biological assays.

  16. The preparation of highly water-soluble multi-walled carbon nanotubes by irreversible noncovalent functionalization with a pyrene-carrying polymer

    International Nuclear Information System (INIS)

    Xue Chaohua; Zhou Renjia; Shi Minmin; Gao Yan; Wu Gang; Chen Hongzheng; Wang Mang; Zhang Xiaobin

    2008-01-01

    Multi-walled carbon nanotubes (MWNTs) have been solubilized in water via a noncovalent method of exfoliation and centrifugation cycles with the assistance of hydrolyzed poly(styrene-co-maleic anhydride) carrying pyrene (HPSMAP). After the obtained solution was micro-filtered and dried, a water-soluble complex of HPSMAP-MWNTs was obtained. The solubility of HPSMAP-MWNTs was measured to be 46.2 mg ml -1 with a net MWNT concentration of 7.4 mg ml -1 in water. Thermal gravimetric analyses showed that there was a large amount of polymer remaining on the surface of MWNTs irreversibly after thoroughly removing the free polymer. Other characterizations using transmission electron microscopy, Fourier transform infrared (FTIR) spectroscopy, fluorescence spectra, and fluorescence decay were conducted

  17. Electronic Paramagnetic Resonance (EPR) of free radicals induced by X-rays in pyrene

    International Nuclear Information System (INIS)

    Moya Partiti, C.S. de.

    1982-01-01

    Pyrene single crystals C 16 H 10 , irradiated by X-rays, at room temperature, were studied by EPR technique, to determine free radicals formed by radiation. The angular dependence of EPR spectra was explained by the presence of two kinds of radicals with an aditional hydrogen: 2-H 2 pyrene and 3-H 2 pyrene. It was studied the isothermic decay of the EPR signal and two typical values for the activation energy were found = (1,9+-0,1) eV and (1,93+-0,03) eV. (author) [pt

  18. Photochemistry of pyrene with water at low temperature: study of atmospherical and astrochemical interest.

    Science.gov (United States)

    Guennoun, Zohra; Aupetit, Christian; Mascetti, Joëlle

    2011-03-17

    Photochemistry of a polyaromatic hydrocarbon, pyrene C(16)H(10), with water has been investigated at cryogenic temperatures. Photoprocessing of this species, performed at λ > 235 nm, in argon matrices, adsorbed onto amorphous water surfaces, and trapped in solid water, led to the formation of ketonic isomers, C(16)H(10)O, and possibly quinones. These species have been identified for the first time by infrared spectroscopy with the support of isotopic substitution experiments and DFT calculations. These oxidized pyrene-like species, of atmospherical and astrochemical interest, most likely arise from a tautomeric rearrangement of their analogous hydroxylated molecules, these latter being formed by reaction of water with pyrene cations.

  19. Effects of pyrene exposure and temperature on early development of two co-existing Arctic copepods

    DEFF Research Database (Denmark)

    Grenvald, Julie Cornelius; Nielsen, Torkel Gissel; Hjorth, Morten

    2013-01-01

    Oil exploration is expected to increase in the near future in Western Greenland. At present, effects of exposure to oil compounds on early life-stages of the ecologically important Calanus spp. are unknown. We investigated the effects of the oil compound pyrene, on egg hatching and naupliar...... with temperature at high pyrene concentration in C. finmarchicus. Both Calanus species were affected by pyrene exposure but C. finmarchicus was more sensitive compared to C. glacialis. Lowered growth rate and increased mortality of the naupliar stages entail reduced recruitment to copepod populations. Exposure...

  20. Peptide-Carrier Conjugation

    DEFF Research Database (Denmark)

    Hansen, Paul Robert

    2015-01-01

    To produce antibodies against synthetic peptides it is necessary to couple them to a protein carrier. This chapter provides a nonspecialist overview of peptide-carrier conjugation. Furthermore, a protocol for coupling cysteine-containing peptides to bovine serum albumin is outlined....

  1. DNA-cell conjugates

    Science.gov (United States)

    Hsiao, Shih-Chia; Francis, Matthew B.; Bertozzi, Carolyn; Mathies, Richard; Chandra, Ravi; Douglas, Erik; Twite, Amy; Toriello, Nicholas; Onoe, Hiroaki

    2018-05-15

    The present invention provides conjugates of DNA and cells by linking the DNA to a native functional group on the cell surface. The cells can be without cell walls or can have cell walls. The modified cells can be linked to a substrate surface and used in assay or bioreactors.

  2. DNA-cell conjugates

    Science.gov (United States)

    Hsiao, Shih-Chia; Francis, Matthew B.; Bertozzi, Carolyn; Mathies, Richard; Chandra, Ravi; Douglas, Erik; Twite, Amy; Toriello, Nicholas; Onoe, Hiroaki

    2016-05-03

    The present invention provides conjugates of DNA and cells by linking the DNA to a native functional group on the cell surface. The cells can be without cell walls or can have cell walls. The modified cells can be linked to a substrate surface and used in assay or bioreactors.

  3. Cubosome formulations stabilized by a dansyl-conjugated block copolymer for possible nanomedicine applications.

    Science.gov (United States)

    Murgia, Sergio; Falchi, Angela Maria; Meli, Valeria; Schillén, Karin; Lippolis, Vito; Monduzzi, Maura; Rosa, Antonella; Schmidt, Judith; Talmon, Yeshayahu; Bizzarri, Ranieri; Caltagirone, Claudia

    2015-05-01

    We present here an innovative, fluorescent, monoolein-based cubosome dispersion. Rather than embedded within the monoolein palisade, the fluorescent imaging agent, namely dansyl, was conjugated to the terminal ethylene oxide moieties of the block copolymer Pluronic F108. We discuss the physicochemical and photophysical properties of this fluorescent Pluronic and of a cubosome formulation stabilized by a mixture of dansyl-conjugated and non-conjugated Pluronic, also including an anticancer drug (quercetin). Furthermore, we performed biocompatibility tests against HeLa cells to assess internalization and cytotoxicity features of this nanoparticles aqueous dispersion. Cryo-TEM, SAXS, and DLS analysis, proved the bicontinuous cubic inner nanostructure and the morphology of this fluorescent cubosome dispersion, while photophysical measurements and biocompatibility results basically validate their potential use for theranostic nanomedicine applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. FLUORESCENCE SPECTROSCOPIC STUDY OF THE FORMATION OF HYDROPHOBIC MICRODOMAINS IN AQUEOUS-SOLUTIONS OF POLY(ALKYLMETHYLDIALLYLAMMONIUM BROMIDES)

    NARCIS (Netherlands)

    YANG, YJ; Engberts, Jan B F N

    The conformational state of poly(alkylmethyldiallylammonium bromides) was studied in aqueous solutions using pyrene as a fluorescence probe. The results are indicative for the formation of hydrophobic microdomains in the case of several copolymers which possess sufficiently hydrophobic alkyl side

  5. Monitoring i-motif transitions through the exciplex emission of a fluorescent probe incorporating two (Py)A units.

    Science.gov (United States)

    Lee, Il Joon; Kim, Byeang Hyean

    2012-02-18

    Pairs of pyrene-modified deoxyadenosine ((Py)A) units induce a stable interstrand i-motif structure, which can be characterized by a change in the fluorescence λ(max), with an exciplex emission that is not observable in its single-strand structure. This journal is © The Royal Society of Chemistry 2012

  6. Recent Advances in Conjugated Polymers for Light Emitting Devices

    Science.gov (United States)

    AlSalhi, Mohamad Saleh; Alam, Javed; Dass, Lawrence Arockiasamy; Raja, Mohan

    2011-01-01

    A recent advance in the field of light emitting polymers has been the discovery of electroluminescent conjugated polymers, that is, kind of fluorescent polymers that emit light when excited by the flow of an electric current. These new generation fluorescent materials may now challenge the domination by inorganic semiconductor materials of the commercial market in light-emitting devices such as light-emitting diodes (LED) and polymer laser devices. This review provides information on unique properties of conjugated polymers and how they have been optimized to generate these properties. The review is organized in three sections focusing on the major advances in light emitting materials, recent literature survey and understanding the desirable properties as well as modern solid state lighting and displays. Recently, developed conjugated polymers are also functioning as roll-up displays for computers and mobile phones, flexible solar panels for power portable equipment as well as organic light emitting diodes in displays, in which television screens, luminous traffic, information signs, and light-emitting wallpaper in homes are also expected to broaden the use of conjugated polymers as light emitting polymers. The purpose of this review paper is to examine conjugated polymers in light emitting diodes (LEDs) in addition to organic solid state laser. Furthermore, since conjugated polymers have been approved as light-emitting organic materials similar to inorganic semiconductors, it is clear to motivate these organic light-emitting devices (OLEDs) and organic lasers for modern lighting in terms of energy saving ability. In addition, future aspects of conjugated polymers in LEDs were also highlighted in this review. PMID:21673938

  7. Carcinogenicity of the environmental pollutants cyclopenteno-(cd)pyrene and cyclopentano(cd)pyrene in mouse skin

    Energy Technology Data Exchange (ETDEWEB)

    Cavalieri, E.; Rogan, E.; Toth, B.; Munhall, A.

    1981-01-01

    Cyclopenteno(cd)pyrene (CPEP) is a widespread environmental pollutant. This hydrocarbon and its 3,4-dihydro derivative, cyclopentano(cd)pyrene (CPAP), were tested on skin in a two-stage initiation-promotion experiment in CD-1 mice and by repeated application in Swiss mice. The biological effect of CPEP and CPAP was compared to that of benzo(a)-pyrene (BP). Nine-week-old female CD-1 mice in groups of 30 were treated every other day over a 20-day period at mini-dose levels of 0.18, 0.06 and 0.02 mumol of CPEP or CPAP in acetone. One group was treated with BP at the low mini-dose level. Initiation was followed by twice weekly application of tetradecanoyl phorbol acetate for 40 weeks. In the second experiments, nine-week-old female Swiss mice in groups of 30 were treated at dose levels of 1.8, 0.6 and 0.2 mumol CPEP or CPAP in acetone twice weekly for 30 weeks. One group was treated with BP at the low dose. CPAP was virtually inactive in both studies. In the initiation-promotion experiment CPEP was inactive at the low dose level, whereas BP exhibited significant tumorigenicity. At the medium and high doses CPEP showed weak, but statistically insignificant, tumorigenic activity. Repeated application of CPEP at the high, medium and low doses resulted in tumor incidences of 23, 37 and 57%, respectively. This reverse dose-response may be due to the relatively high cytotoxicity of CPEP, BP, which was compared to CPEP at the low dose, elicited tumors in 100% of the mice. Most of the CPEP-induced neoplasms were malignant and some metastasized to lungs and lymph nodes. The inactivity of CPAP suggests the carcinogenicity of CPEP is probably due to formation of the ultimate metabolite CPEP 3,4-oxide. In view of the abundance of CPEP in environmental and occupational pollutants, its moderately potent carcinogenicity may represent a potential health hazard.

  8. Conjugate adaptive optics with remote focusing in multiphoton microscopy

    Science.gov (United States)

    Tao, Xiaodong; Lam, Tuwin; Zhu, Bingzhao; Li, Qinggele; Reinig, Marc R.; Kubby, Joel

    2018-02-01

    The small correction volume for conventional wavefront shaping methods limits their application in biological imaging through scattering media. In this paper, we take advantage of conjugate adaptive optics (CAO) and remote focusing (CAORF) to achieve three-dimensional (3D) scanning through a scattering layer with a single correction. Our results show that the proposed system can provide 10 times wider axial field of view compared with a conventional conjugate AO system when 16,384 segments are used on a spatial light modulator. We demonstrate two-photon imaging with CAORF through mouse skull. The fluorescent microspheres embedded under the scattering layers can be clearly observed after applying the correction.

  9. Topological, functional, and dynamic properties of the protein interaction networks rewired by benzo(a)pyrene

    International Nuclear Information System (INIS)

    Ba, Qian; Li, Junyang; Huang, Chao; Li, Jingquan; Chu, Ruiai; Wu, Yongning; Wang, Hui

    2015-01-01

    Benzo(a)pyrene is a common environmental and foodborne pollutant that has been identified as a human carcinogen. Although the carcinogenicity of benzo(a)pyrene has been extensively reported, its precise molecular mechanisms and the influence on system-level protein networks are not well understood. To investigate the system-level influence of benzo(a)pyrene on protein interactions and regulatory networks, a benzo(a)pyrene-rewired protein interaction network was constructed based on 769 key proteins derived from more than 500 literature reports. The protein interaction network rewired by benzo(a)pyrene was a scale-free, highly-connected biological system. Ten modules were identified, and 25 signaling pathways were enriched, most of which belong to the human diseases category, especially cancer and infectious disease. In addition, two lung-specific and two liver-specific pathways were identified. Three pathways were specific in short and medium-term networks (< 48 h), and five pathways were enriched only in the medium-term network (6 h–48 h). Finally, the expression of linker genes in the network was validated by Western blotting. These findings establish the overall, tissue- and time-specific benzo(a)pyrene-rewired protein interaction networks and provide insights into the biological effects and molecular mechanisms of action of benzo(a)pyrene. - Highlights: • Benzo(a)pyrene induced scale-free, highly-connected protein interaction networks. • 25 signaling pathways were enriched through modular analysis. • Tissue- and time-specific pathways were identified

  10. Topological, functional, and dynamic properties of the protein interaction networks rewired by benzo(a)pyrene

    Energy Technology Data Exchange (ETDEWEB)

    Ba, Qian [Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai (China); Key Laboratory of Food Safety Risk Assessment, Ministry of Health, Beijing (China); Li, Junyang; Huang, Chao [Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai (China); Li, Jingquan; Chu, Ruiai [Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai (China); Key Laboratory of Food Safety Risk Assessment, Ministry of Health, Beijing (China); Wu, Yongning, E-mail: wuyongning@cfsa.net.cn [Key Laboratory of Food Safety Risk Assessment, Ministry of Health, Beijing (China); Wang, Hui, E-mail: huiwang@sibs.ac.cn [Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai (China); Key Laboratory of Food Safety Risk Assessment, Ministry of Health, Beijing (China); School of Life Science and Technology, ShanghaiTech University, Shanghai (China)

    2015-03-01

    Benzo(a)pyrene is a common environmental and foodborne pollutant that has been identified as a human carcinogen. Although the carcinogenicity of benzo(a)pyrene has been extensively reported, its precise molecular mechanisms and the influence on system-level protein networks are not well understood. To investigate the system-level influence of benzo(a)pyrene on protein interactions and regulatory networks, a benzo(a)pyrene-rewired protein interaction network was constructed based on 769 key proteins derived from more than 500 literature reports. The protein interaction network rewired by benzo(a)pyrene was a scale-free, highly-connected biological system. Ten modules were identified, and 25 signaling pathways were enriched, most of which belong to the human diseases category, especially cancer and infectious disease. In addition, two lung-specific and two liver-specific pathways were identified. Three pathways were specific in short and medium-term networks (< 48 h), and five pathways were enriched only in the medium-term network (6 h–48 h). Finally, the expression of linker genes in the network was validated by Western blotting. These findings establish the overall, tissue- and time-specific benzo(a)pyrene-rewired protein interaction networks and provide insights into the biological effects and molecular mechanisms of action of benzo(a)pyrene. - Highlights: • Benzo(a)pyrene induced scale-free, highly-connected protein interaction networks. • 25 signaling pathways were enriched through modular analysis. • Tissue- and time-specific pathways were identified.

  11. Metabolic activation and DNA binding of benzo(a)pyrene in cultured human bronchus

    DEFF Research Database (Denmark)

    Yang, Shen K.; Gelboin, Harry V.; Trump, Benjamin F.

    1977-01-01

    . The predominant metabolite formed by human bronchus from the (-)-trans-7,8-diol is found by high-pressure liquid chromatographic analysis to be the diol-epoxide r-7,t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahy-drobenzo(a)pyrene. The results suggest that this diol-epoxide is the major benzo(a)pyrene metabolite bound...

  12. Photodegradation of polycyclic aromatic hydrocarbon pyrene by iron oxide in solid phase

    International Nuclear Information System (INIS)

    Wang, Y.; Liu, C.S.; Li, F.B.; Liu, C.P.; Liang, J.B.

    2009-01-01

    To better understand the photodegradation of polycyclic aromatic hydrocarbons (PAH) in solid phase in natural environment, laboratory experiments were conducted to study the influencing factors, kinetics and intermediate compound of pyrene photodegradation by iron oxides. The results showed that the pyrene photodegradation rate followed the order of α-FeOOH > α-Fe 2 O 3 > γ-Fe 2 O 3 > γ-FeOOH at the same reaction conditions. Lower dosage of α-FeOOH and higher light intensity increased the photodegradation rate of pyrene. Iron oxides and oxalic acid can set up a photo-Fenton-like system without additional H 2 O 2 in solid phase to enhance the photodegradation of pyrene under UV irradiation. All reaction followed the first-order reaction kinetics. The half-life (t 1/2 ) of pyrene in the system showed the higher efficiencies of using iron oxide as photocatalyst to degrade pyrene. Intermediate compound pyreno was found during photodegradation reactions by gas chromatography-mass spectrometry (GC-MS). The photodegradation efficiency for PAHs in this photo-Fenton-like system was also confirmed by using the contaminated soil samples. This work provides some useful information to understand the remediation of PAHs contaminated soils by photochemical techniques under practical condition

  13. How to link pyrene to its host lipid to minimize the extent of membrane perturbations and to optimize pyrene dimer formation

    DEFF Research Database (Denmark)

    Franova, M. D.; Repakova, J.; Holopainen, J. M.

    2014-01-01

    We study how lipid probes based on pyrene-labeling could be designed to minimize perturbations in lipid bilayers, and how the same design principles could be exploited to develop probes which gauge lipid dynamics primarily within a single lipid monolayer or between them. To this end, we use......, simulations suggest that formation of dimers is a slow process, where the rate is limited by both lateral diffusion and the dimerization process once the two probes are neighbors to one another. Typical lifetimes of pyrene dimers turn out be of the order of nanoseconds. The results are expected to pave...

  14. Heavy atom induced room temperature fluorescence quenching of PAH from a glucose glass

    Energy Technology Data Exchange (ETDEWEB)

    Marlow, Matt, E-mail: matthew.marlow@nicholls.edu

    2017-06-15

    Sugar glasses are a relatively new matrix for solid-matrix luminescence. Molecular interactions within the sugar glass are not well understood. Fluorescence quenching was used to investigate molecular interactions within the sugar glass matrix. The room temperature fluorescence quenching of pyrene and naphthalene was observed from a glucose glass. The heavy atom salt NaI was the quencher. Two solvent compositions 50/50 and 60/40 MeOH/water, used for glass preparation, were examined for their effect on glass rigidity and molecular interactions. A complex static mechanism was observed for glasses prepared with 50/50 MeOH/water. This data was fit to the sphere of action model and associations constants determined. A Stern-Volmer static mechanism of quenching was observed for glasses prepared with 60/40 MeOH/water. This data fit the Stern-Volmer equation and association constants were determined. A larger association constant was observed for pyrene compared to naphthalene for both solvent systems used. Pyrene had a larger association constant with a sugar glass prepared with 60/40 MeOH/water compared to 50/50 MeOH/water implying a greater association between pyrene and iodide. The greater association is a reflection of a more rigid internal environment for the sugar glass prepared with 60/40 MeOH/water.

  15. Effect of sunlight irradiation on photocatalytic pyrene degradation in contaminated soils by micro-nano size TiO2

    International Nuclear Information System (INIS)

    Chang Chien, S.W.; Chang, C.H.; Chen, S.H.; Wang, M.C.; Madhava Rao, M.; Satya Veni, S.

    2011-01-01

    The enhanced catalytic pyrene degradation in quartz sand and alluvial and red soils by micro-nano size TiO 2 in the presence and absence of sunlight was investigated. The results showed that the synergistic effect of sunlight irradiation and TiO 2 was more efficient on pyrene degradation in quartz sand and red and alluvial soils than the corresponding reaction system without sunlight irradiation. In the presence of sunlight irradiation, the photooxidation (without TiO 2 ) of pyrene was very pronounced in alluvial and red soils and especially in quartz sand. However, in the absence of sunlight irradiation, the catalytic pyrene degradation by TiO 2 and the photooxidation (without TiO 2 ) of pyrene were almost nil. This implicates that ultra-violet (UV) wavelength range of sunlight plays an important role in TiO 2 -enhanced photocatalytic pyrene degradation and in photooxidation (without TiO 2 ) of pyrene. The percentages of photocatalytic pyrene degradation by TiO 2 in quartz sand, alluvial and red soils under sunlight irradiation were 78.3, 23.4, and 31.8%, respectively, at 5 h reaction period with a 5% (w/w) dose of the amended catalyst. The sequence of TiO 2 -enhanced catalytic pyrene degradation in quartz sand and alluvial and red soils was quartz sand > red soil > alluvial soil, due to different texture and total organic carbon (TOC) contents of the quartz sand and other two soils. The differential Fourier transform infrared (FT-IR) spectra of degraded pyrene in alluvial soil corroborate that TiO 2 -enhanced photocatalytic degradation rate of degraded pyrene was much greater than photooxidation (without TiO 2 ) rate of degraded pyrene. Based on the data obtained, the importance for the application of TiO 2 -enhanced photocatalytic pyrene degradation and associated organic contaminants in contaminated soils was elucidated. - Highlights: → Synergistic effect of sunlight irradiation and TiO 2 promoted degradation of pyrene. → Micro-nano size TiO 2 enhanced

  16. Principles of conjugating quantum dots to proteins via carbodiimide chemistry

    International Nuclear Information System (INIS)

    Song Fayi; Chan, Warren C W

    2011-01-01

    The covalent coupling of nanomaterials to bio-recognition molecules is a critical intermediate step in using nanomaterials for biology and medicine. Here we investigate the carbodiimide-mediated conjugation of fluorescent quantum dots to different proteins (e.g., immunoglobulin G, bovine serum albumin, and horseradish peroxidase). To enable these studies, we developed a simple method to isolate quantum dot bioconjugates from unconjugated quantum dots. The results show that the reactant concentrations and protein type will impact the overall number of proteins conjugated onto the surfaces of the quantum dots, homogeneity of the protein–quantum dot conjugate population, quantum efficiency, binding avidity, and enzymatic kinetics. We propose general principles that should be followed for the successful coupling of proteins to quantum dots.

  17. Synthesis and characterization of novel 2, 2'-bipyrimidine fluorescent derivative for protein binding

    Directory of Open Access Journals (Sweden)

    Padalkar Vikas S

    2011-11-01

    Full Text Available Abstract Background Fluorescent dyes with biocompatible functional group and good fluorescence behavior are used as biosensor for monitoring different biological processes as well as detection of protein assay. All reported fluorophore used as sensors are having high selectivity and sensitivity but till there is more demand to synthesized new fluorophore which have improved fluorescence properties and good biocompatibility. Results Novel 4, 4'-(1, 1'-(5-(2-methoxyphenoxy-[2, 2'-bipyrimidine]-4, 6-diylbis(1H-pyrazol-3, 1-diyl dianiline fluorescent dye was synthesized by multistep synthesis from 2-phenylacetonitrile, 2-chloropyrimidine and 2-methoxyphenol. This dye has absorption at 379 nm with intense single emission at 497 nm having fairly good quantum yield (0.375 and Stokes shift. The intermediates and dye were characterized by FT-IR, 1H NMR, 13C NMR and Mass spectral analysis. The pyrazole bipyrimidine based fluorescent dye possessing two amino groups suitable for binding with protein is reported. Its utility as a biocompatible conjugate was explained by conjugation with bovine serum albumin. The method is based on direct fluorescence detection of fluorophore-labelled protein before and after conjugation. Purified fluorescent conjugate was subsequently analyzed by fluorimetry. The analysis showed that the tested conjugation reaction yielded fluorescent conjugates of the dye through carbodiimide chemistry. Conclusion In summery synthesized fluorophore pyrazole-bipyrimidine has very good interaction towards protein bovine serum albumin and it acts as good candidate for protein assay.

  18. Quantum dot conjugates in a sub-micrometer fluidic channel

    Science.gov (United States)

    Stavis, Samuel M.; Edel, Joshua B.; Samiee, Kevan T.; Craighead, Harold G.

    2010-04-13

    A nanofluidic channel fabricated in fused silica with an approximately 500 nm square cross section was used to isolate, detect and identify individual quantum dot conjugates. The channel enables the rapid detection of every fluorescent entity in solution. A laser of selected wavelength was used to excite multiple species of quantum dots and organic molecules, and the emission spectra were resolved without significant signal rejection. Quantum dots were then conjugated with organic molecules and detected to demonstrate efficient multicolor detection. PCH was used to analyze coincident detection and to characterize the degree of binding. The use of a small fluidic channel to detect quantum dots as fluorescent labels was shown to be an efficient technique for multiplexed single molecule studies. Detection of single molecule binding events has a variety of applications including high throughput immunoassays.

  19. Quantum dot conjugates in a sub-micrometer fluidic channel

    Science.gov (United States)

    Stavis, Samuel M [Ithaca, NY; Edel, Joshua B [Brookline, MA; Samiee, Kevan T [Ithaca, NY; Craighead, Harold G [Ithaca, NY

    2008-07-29

    A nanofluidic channel fabricated in fused silica with an approximately 500 nm square cross section was used to isolate, detect and identify individual quantum dot conjugates. The channel enables the rapid detection of every fluorescent entity in solution. A laser of selected wavelength was used to excite multiple species of quantum dots and organic molecules, and the emission spectra were resolved without significant signal rejection. Quantum dots were then conjugated with organic molecules and detected to demonstrate efficient multicolor detection. PCH was used to analyze coincident detection and to characterize the degree of binding. The use of a small fluidic channel to detect quantum dots as fluorescent labels was shown to be an efficient technique for multiplexed single molecule studies. Detection of single molecule binding events has a variety of applications including high throughput immunoassays.

  20. Benzo(a)pyrene diol epoxides as intermediates in nucleic acid binding in vitro and in vivo.

    Science.gov (United States)

    Weinstein, I B; Jeffrey, A M; Jennette, K W; Blobstein, S H; Harvey, R G; Harris, C; Autrup, H; Kasai, H; Nakanishi, K

    1976-08-13

    Evidence has been obtained that a specific isomer of a diol epoxide derivative of benzo(a)pyrene, (+/-)-7 beta,8alpha-dihydroxy-9alpha, 10alpha-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene, is an intermediate in the binding of benzo(a)pyrene to RNA in cultured bovine bronchial mucosa. An adduct is formed between position 10 of this derivative and the 2-amino group of guanine.

  1. Persistence of urinary excretion products of benzo(a)pyrene

    International Nuclear Information System (INIS)

    Uziel, M.; Haglund, R.; White, D.A.

    1988-01-01

    Persistence of DNA-adducts has been observed in a variety of experimental circumstances and has been suggested as one potential mechanism for explaining the long-term delay before expression of proliferative disease. In this concept, a stable DNA-adduct, which is a remnant of a prior exposure in a nondividing cell, would not express the genotoxic effect until the cells were stimulated to divide, and thus explain the long-term delay in expression of cancer. An alternative view of the observation of persistent DNA-adducts, described in this communication, is the continuing replenishment of DNA adducts by formation and turnover of these adducts from exposure to a constant supply of the ultimate carcinogenic species derived from a prior exposure. It is of interest to note that virtually all experiments where ''persistent'' adducts have been observed have been high dose exposures. During the course of experiments designed to develop improved methods for detection of DNA adducts and related derivatives derived from polynuclear aromatic hydrocarbons (PAH), we observed that there was a continuous excretion of urinary derivatives of the injected benzo(a)pyrene (BaP) beyond the initial burst of detoxification. This report describes the time dependent distribution of those derivatives in blood, urine, feces, and at the site of injection. 11 refs., 5 figs., 4 tabs

  2. Estimating the Biodegradation Kinetics by Mixed Culture Degrading Pyrene (Pyr

    Directory of Open Access Journals (Sweden)

    B. S. U. Ibn Abubakar

    2017-02-01

    Full Text Available Biodegradation and kinetics of Pyrene (Pyr degradation by a mixed culture previously isolated from hydrocarbon-polluted soil were conducted. Preliminary investigation on environmental factors affecting the degradation of Pyr such as temperature, pH and concentrations of Pyr was performed. These factors were optimised and established in aqueous experiments. In order to develop kinetics of Pyr degradation, an optimum temperature of 30oC and pH of 7.0 was used. Biodegradation kinetics was carried out, at first, using higher concentration between (100-700 ppm as sole source of carbon in mineral salt medium (MSM supplemented with 0.1% yeast extract. The result indicated that a range of concentration between (100-700 ppm inhibits the performance of the mixed culture. A concentration range between (10-100 ppm did not inhibit the growth of the mixed culture. A First-order rate constant, k was higher (0.0487 mg/lh with a substrate concentration of 20 ppm than other concentrations. The average degradation rate constant is 0.0029 mg/Lh for all the concentrations tested. This indicated that the mixed culture could degrade over 0.0696 ppm of Pyr per day. It also confirmed that kinetics of microbial degradation was partially fitted into Monod model. The data can be used to estimate biodegradation of Pyr by a mixed culture and preliminarily estimation of degradation rates.

  3. Compartmental analysis of benzo[a]pyrene toxicokinetics

    International Nuclear Information System (INIS)

    Bevan, D.R.; Weyand, E.H.

    1986-01-01

    A multicompartmental model to describe quantitatively the toxicokinetics of benzo[a]pyrene (B[a]P) was developed using SAAM (Simulation, Analysis and Modeling). [ 3 H]-B[a]P dissolved in triethylene glycol was administered intratracheally to male Sprague-Dawley rats, and amounts of [ 3 H] were quantified in various tissues at selected times up to 6 hr after administration. Elimination of [ 3 H]-B[a]P and/or metabolites from lungs was biphasic, with half-times of 5.3 min. and 116 min. [ 3 H]-B[a]P and/or metabolites were subsequently distributed primarily to liver and carcass (muscle, bones, fat, skin and associated blood). Carcass contained about 20% of administered [ 3 H] at 6 hr after administration, and agreement between the model and experimental data required that the carcass be modeled as two compartments, one with rapid and one with slow exchange. Approximately 50% of the administered dose was excreted in feces in 6 hr and only 2% appeared in urine. Enterohepatic circulation was accounted for in the model. The model was then used to predict amounts of [ 3 H]-B[a]P and/or metabolites which would be excreted into bile in animals with bile duct cannulas, and good agreement between the model and data was observed

  4. Tow-step degradation of pyrene by white-rot fungi and soil microorganisms

    International Nuclear Information System (INIS)

    Wische, C. in der; Martens, R.; Zadrazil, F.

    1996-01-01

    The effect of soil microorganisms on mineralization of 14 C-labelled pyrene by white-rot fungi in solid-state fermentation was investigated. Two strains of white-rot fungi, Dichomitus squalens and a Pleurotus sp., were tested. The fungi were incubated on milled wheat straw contaminated with [ 14 C]pyrene for 15 weeks. CO 2 and 14 CO 2 liberated from the cultures were determined weekly. To study the effect of soil microorganisms on respiration and [ 14 C]pyrene mineralization in different periods of fungal development, the fungal substrate was covered with soil at different times of incubation (after 0, 1, 3, 5, 7, 9 or 11 weeks). The two fungi showed contrasting ecological behaviour in competition with the soil microflora. Pleurotus sp. was highly resistant to microbial attack and had the ability to penetrate the soil. D. squalens was less competitive and did not colonize the soil. The resistance of the fungus was dependent on the duration of fungal preincubation. Mineralization of [ 14 C]pyrene by mixed cultures of D. squalens and soil microorganisms was higher than by the fungus or the soil microflora alone when soil was added after 3 weeks of incubation or later. With Pleurotus sp., the mineralization of [ 14 C]pyrene was enhanced by the soil microflora irrespective of the time of soil application. With D. squalens, which in pure culture mineralized less [ 14 C]pyrene than did Pleurotus sp., the increase of [ 14 C]pyrene mineralization caused by soil application was higher than with Pleurotus sp. (orig.)

  5. Microfluidic Fabrication of Conjugated Polymer Sensor Fibers

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Imsung; Song, Simon [Hanyang University, Seoul (Korea, Republic of)

    2014-10-15

    We propose a fabrication method for polydiacetylene (PDA)-embedded hydrogel microfibers on a microfluidic chip. These fibers can be applied to the detection of cyclodextrines (CDs), which are a family of sugar and aluminum ions. PDA, a family of conjugated polymers, has unique characteristics when used for a sensor, because it undergoes a blue-to-red color transition and nonfluorescence-to-fluorescence transition in response to environmental stimulation. PDAs have different sensing characteristics depending on the head group of PCDA. By taking advantage of ionic crosslinking-induced hydrogel formation and the 3D hydrodynamic focusing effect on a microfluidic chip, PCDA-EDEA-derived diacetylene (DA) monomer-embedded microfibers were successfully fabricated. UV irradiation of the fibers afforded blue-colored PDA, and the resulting blue PDA fibers underwent a phase transition to red and emitted red fluorescence upon exposure to CDs and aluminum ions. Their fluorescence intensity varied depending on the CDs and aluminum ion concentrations. This phase transition was also observed when the fibers were dried.

  6. Functional properties of nisin-carbohydrate conjugates formed by radiation induced Maillard reaction

    Science.gov (United States)

    Muppalla, Shobita R.; Sonavale, Rahul; Chawla, Surinder P.; Sharma, Arun

    2012-12-01

    Nisin-carbohydrate conjugates were prepared by irradiating nisin either with glucose or dextran. Increase in browning and formation of intermediate products was observed with a concomitant decrease in free amino and reducing sugar groups indicating occurrence of the Maillard reaction catalyzed by irradiation. Nisin-carbohydrate conjugates showed a broad spectrum antibacterial activity against Gram negative bacteria (Escherichia coli, Pseudomonas fluorescence) as well as Gram positive bacteria (Staphylococcus aureus, Bacillus cereus). Results of antioxidant assays, including that of DPPH radical-scavenging activity and reducing power, showed that the nisin-dextran conjugates possessed better antioxidant potential than nisin-glucose conjugate. These results suggested that it was possible to enhance the functional properties of nisin by preparing radiation induced conjugates suitable for application in food industry.

  7. ANTIBODIES TO BENZO[A]PYRENE AND POLYMORPHISMS OF CYP1A1*2A, CYP1A2*1F, GSTT1, AND GSTM1 GENES IN HEALTHY MEN AND LUNG CANCER PATIENTS

    Directory of Open Access Journals (Sweden)

    A. N. Glushkov

    2016-01-01

    Full Text Available Some genetic polymorphisms of CYP and GST enzymes metabolizing low-molecular weight xenobiotics may represent endogenous risk factors for carcinogenesis. However, possible relationships between the enzyme activities, amounts of carcinogen adducts and synthesis of anticarcinogen antibodies in humans (including cancer patients are still poorly studied. The purpose of this study was to identify possible associations between occurrence of antibodies against benzo[a]pyrene, and frequency of genetic polymorphisms of CYP1A1*2A, CYP1A2*1F, GSTT1, GSTM1 in healthy men and in lung cancer patients. Materials and methods. We have examined 203 men with non-small cell lung cancer and 267 apparently healthy donors without respiratory diseases. A non-competitive solid phase immunoassay of antibodies to benzo[a]pyrene was performed. Analysis of polymorphic loci within CYP1A1 (rs4646903, CYP1A2 (rs762551, GSTP1 (rs1695, rs1138272 was performed by means of real-time PCR using TaqMan technology. Null-alleles of GSTM1 (del, GSTT1 (del genes were detected by multiplex PCR with real-time fluorescent assay. Results. Among the lung cancer patients, the proportion of cases with a high level of IgG antibodies to benzo[a]pyrene in carriers of GSTT1+ and GSTM1+ in conjunction with the CYP1A2*1F C allele was significantly greater than in AA homozygotes CYP1A2*1F. The risk of lung cancer was increased to 5.5 in carriers of CYP1A2*1F C allele combined with GSTT1+ and GSTM1+ at high levels of IgG antibodies to benzo [a] pyrene. In healthy male donors, we have not found differences between the incidence of low and high levels of IgG anti-benzo[a]pyrene antibodies in the carriers of certain CYP1A1*2A, CYP1A2*1F, GSTT1 and GSTM1 genotypes. Conclusions. We have first reported a relationship between CYP1 and GST gene polymorphisms and specific immune response to chemical carcinogens in lung cancer patients. Immunoassays of IgG antibodies to benzo[a]pyrene combined with molecular

  8. Study of the Conformational State of Non-Cross-Linked and Cross-Linked Poly(alkylmethyldiallylammonium chlorides) in Aqueous Solution by Fluorescence Probing

    NARCIS (Netherlands)

    Wang, Guang-Jia; Engberts, Jan B.F.N.

    The aggregation behaviour of novel non-cross-linked and cross-linked poly(alkylmethyldiallylammonium chlorides) in aqueous solutions has been investigated by fluorescence spectroscopy using pyrene as a probe. These copolymers were found to exhibit similar aggregate properties as the corresponding

  9. Comparative synchronous fluorescence spectrophotometry and 32P-postlabeling analysis of PAH-DNA adducts in human lung and the relationship to TP53 mutations

    DEFF Research Database (Denmark)

    Andreassen, Åshild; Kure, Elin H.; Nielsen, Per Sabro

    1996-01-01

    Polycyclic aromatic hydrocarbon (PAH)-DNA adducts were studied in human lung from 39 lung cancer patients by synchronous fluorescence spectrophotometric (SFS) and 32P-postlabeling assays. Regression analysis of the samples failed to detect any correlation between benzo[a]pyrene-diolepoxide (BPDE)...

  10. Synthesis and photophysicochemical studies of a water soluble conjugate between folic acid and zinc tetraaminophthalocyanine

    Energy Technology Data Exchange (ETDEWEB)

    Khoza, Phindile; Antunes, Edith [Department of Chemistry, Rhodes University, PO Box 94, Grahamstown (South Africa); Chen, Ji-Yao [State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433 (China); Nyokong, Tebello, E-mail: t.nyokong@ru.ac.za [Department of Chemistry, Rhodes University, PO Box 94, Grahamstown (South Africa)

    2013-02-15

    This work reports on the synthesis of zinc tetraaminophthalocyanine (ZnTAPc) functionalized with folic acid (FA), forming ZnTAPcFA. The conjugate between FA and ZnTAPc was soluble in water whereas ZnTAPc alone is not. The structure of ZnTAPcFA conjugate was elucidated by {sup 1}H NMR, MALDI-TOF mass and FTIR spectra. Photophysical and photochemical studies of ZnTAPcFA were conducted in DMSO. The increase in fluorescence quantum yield of the conjugate was accompanied by a decrease in the triplet and singlet oxygen quantum yields. The changes in triplet quantum and singlet oxygen quantum yields were marginal when ZnTAPc was simply mixed with FA without a chemical bond. - Highlights: Black-Right-Pointing-Pointer A conjugate between folic acid and a zinc tetraaminophthalocyanine was formed. Black-Right-Pointing-Pointer The conjugate is water soluble even though the phthalocyanine alone is not. Black-Right-Pointing-Pointer The fluorescence quantum yield of the conjugate was enhanced compared to the phthalocyanine alone. Black-Right-Pointing-Pointer Triplet quantum yields decreased for the conjugate.

  11. Synthesis and photophysicochemical studies of a water soluble conjugate between folic acid and zinc tetraaminophthalocyanine

    International Nuclear Information System (INIS)

    Khoza, Phindile; Antunes, Edith; Chen, Ji-Yao; Nyokong, Tebello

    2013-01-01

    This work reports on the synthesis of zinc tetraaminophthalocyanine (ZnTAPc) functionalized with folic acid (FA), forming ZnTAPcFA. The conjugate between FA and ZnTAPc was soluble in water whereas ZnTAPc alone is not. The structure of ZnTAPcFA conjugate was elucidated by 1 H NMR, MALDI-TOF mass and FTIR spectra. Photophysical and photochemical studies of ZnTAPcFA were conducted in DMSO. The increase in fluorescence quantum yield of the conjugate was accompanied by a decrease in the triplet and singlet oxygen quantum yields. The changes in triplet quantum and singlet oxygen quantum yields were marginal when ZnTAPc was simply mixed with FA without a chemical bond. - Highlights: ► A conjugate between folic acid and a zinc tetraaminophthalocyanine was formed. ► The conjugate is water soluble even though the phthalocyanine alone is not. ► The fluorescence quantum yield of the conjugate was enhanced compared to the phthalocyanine alone. ► Triplet quantum yields decreased for the conjugate

  12. Uptake of Single-Walled Carbon Nanotubes Conjugated with DNA by Microvascular Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Joseph Harvey

    2012-01-01

    Full Text Available Single-walled carbon nanotubes (SWCNTs have been proposed to have great therapeutic potential. SWCNTs conjugated with drugs or genes travel in the systemic circulation to reach target cells or tissues following extravasation from microvessels although the interaction between SWCNT conjugates and the microvascular endothelial cells (ECs remains unknown. We hypothesized that SWCNT-DNA conjugates would be taken up by microvascular ECs and that this process would be facilitated by SWCNTs compared to facilitation by DNA alone. ECs were treated with various concentrations of SWCNT-DNA-FITC conjugates, and the uptake and intracellular distribution of these conjugates were determined by a confocal microscope imaging system followed by quantitative analysis of fluorescence intensity. The uptake of SWCNT-DNA-FITC conjugates (2 μg/mL by microvascular ECs was significantly greater than that of DNA-FITC (2 μg/mL, observed at 6 hrs after treatment. For the intracellular distribution, SWCNT-DNA-FITC conjugates were detected in the nucleus of ECs, while DNA-FITC was restricted to the cytoplasm. The fluorescence intensity and distribution of SWCNTs were concentration and time independent. The findings demonstrate that SWCNTs facilitate DNA delivery into microvascular ECs, thus suggesting that SWCNTs serving as drug and gene vehicles have therapeutic potential.

  13. Mechanism-based inactivation of benzo[a]pyrene hydroxylase by aryl acetylenes and aryl olefins

    International Nuclear Information System (INIS)

    Gan, L.S.; Lu, J.Y.L.; Alworth, W.L.

    1986-01-01

    A series of aryl acetylenes and aryl olefins have been examined as substrates and inhibitors of cytochrome P-450 dependent monooxgenases in liver microsomes from 5,6-benzoflavone or phenobarbital pretreated rats. 1-Ethynylpyrene, 3-ethynylperylene, 2-ethynylfluorene, methyl 1-pyrenyl acetylene, cis- and trans-1-(2-bromovinyl)pyrene, and 1-allylpyrene serve as mechanism-based irreversible inactivators (suicide inhibitors) of benzo[a]pyrene hydroxylase, while 1-vinylpyrene and phenyl 1-pyrenyl acetylene do not cause a detectable suicide inhibition of benzo[a]pyrene hydroxylase. The mechanism-based loss of benzo[a]pyrene hydroxylase caused by the aryl acetylenes is not accompanied by a corresponding loss of the P-450 content of the microsomes (suicide destruction). The suicide inhibition by these aryl acetylenes therefore does not involve covalent binding to the heme moiety of the monooxygenase. Nevertheless, in the presence of NADPH, 3 H-labeled 1-ethynylpyrene becomes covalently attached to the cytochrome P-450 protein; the measured stoichiometry of binding is one 1-ethynylpyrene per P-450 heme unit. The authors conclude that the inhibition of benzo[a]pyrene hydroxylase produced by 1-ethynylpyrene may be related to the mechanism of suicide inhibition of P-450 activity by chloramphenicol rather than the mechanism of suicide destruction of P-450 previously described for acetylene and propyne

  14. Isolation and Identification of Pyrene Mineralizing Mycobacterium spp. from Contaminated and Uncontaminated Sources

    International Nuclear Information System (INIS)

    Lease, C.W.M; Bentham, R.H; Gaskin, S.E; Juhasz, A.L

    2011-01-01

    Mycobacterium isolates obtained from PAH-contaminated and uncontaminated matrices were evaluated for their ability to degrade three-, four- and five-ring PAHs. PAH enrichment studies were prepared using pyrene and inocula obtained from manufacturing gas plant (MGP) soil, uncontaminated agricultural soil, and faeces from Macropus fuliginosus (Western Grey Kangaroo). Three pyrene-degrading microorganisms isolated from the corresponding enrichment cultures had broad substrate ranges, however, isolates could be differentiated based on surfactant, phenol, hydrocarbon and PAH utilisation. 16S rRNA analysis identified all three isolates as Mycobacterium sp. The Mycobacterium spp. could rapidly degrade phenanthrene and pyrene, however, no strain had the capacity to utilise fluorene or benzo[a]pyrene. When pyrene mineralisation experiments were performed, 70-79% of added 14 C was evolved as 14 CO 2 after 10 days. The present study demonstrates that PAH degrading microorganisms may be isolated from a diverse range of environmental matrices. The present study demonstrates that prior exposure to PAHs was not a prerequisite for PAH catabolic activity for two of these Mycobacterium isolates.

  15. Organometallic B12-DNA conjugate

    DEFF Research Database (Denmark)

    Hunger, Miriam; Mutti, Elena; Rieder, Alexander

    2014-01-01

    Design, synthesis, and structural characterization of a B12-octadecanucleotide are presented herein, a new organometallic B12-DNA conjugate. In such covalent conjugates, the natural B12 moiety may be a versatile vector for controlled in vivo delivery of oligonucleotides to cellular targets in hum...

  16. Design, synthesis and photochemical properties of the first examples of iminosugar clusters based on fluorescent cores

    Directory of Open Access Journals (Sweden)

    Mathieu L. Lepage

    2015-05-01

    Full Text Available The synthesis and photophysical properties of the first examples of iminosugar clusters based on a BODIPY or a pyrene core are reported. The tri- and tetravalent systems designed as molecular probes and synthesized by way of Cu(I-catalysed azide–alkyne cycloadditions are fluorescent analogues of potent pharmacological chaperones/correctors recently reported in the field of Gaucher disease and cystic fibrosis, two rare genetic diseases caused by protein misfolding.

  17. Optical Sensing Properties of Pyrene-Schiff Bases toward Different Acids.

    Science.gov (United States)

    Babgi, Bandar A; Alzahrani, Asma

    2016-07-01

    A set of (4-substituted-phenyl)-pyren-1-ylmethylene-amine (PMA) was prepared by the reaction of pyrene-1-carboxaldehyde and the corresponding 4-substituted aniline. The structure of the PMA compounds were confirmed by spectroscopic data (IR, (1)HNMR, (13)CNMR, ISI-MS and elemental analysis. The structure of (4-bromo-phenyl)-pyren-1-ylmethylene-amine (BrPMA) was further confirmed by the single X-ray crystallography. The absorption and emission spectroscopic behaviors were investigated in variant acids. The compounds showed dramatic spectroscopic changes upon acidifying with strong acids and negligible effects when weak acids are used in the acidifications. Hence, the PMA compounds can be used as sensors to distinguish between weak and strong acids.

  18. Conjugation in Escherichia coli

    Science.gov (United States)

    Boyer, Herbert

    1966-01-01

    Boyer, Herbert (Yale University, New Haven, Conn.). Conjugation in Escherichia coli. J. Bacteriol. 91:1767–1772. 1966.—The sex factor of Escherichia coli K-12 was introduced into an E. coli B/r strain by circumventing the host-controlled modification and restriction incompatibilities known to exist between these closely related strains. The sexual properties of the constructed F+ B strain and its Hfr derivatives were examined. These studies showed that the E. coli strain B/r F+ and Hfr derivatives are similar to the E. coli strain K-12 F+ and Hfr derivatives. However, the site of sex factor integration was found to be dependent on the host genome. PMID:5327905

  19. Electrochromic in conjugated polymers

    International Nuclear Information System (INIS)

    Picado Valenzuela, Alfredo

    2007-01-01

    This revision considered object the description of one of the materials with the greatest potential in the field of electrochromic (mainly in the visible region): the conjugated polymers (CP), area of enormous potential both now and in a short time ahead. The CP are insulating materials and organic semiconductors in a state not doped. They can be doped positively or negatively being observed a significant increase in the conductivity and being generated a color change in these materials. The understanding of how optical properties vary based on the chemical structure of the polymer or its mixtures and more precisely of the alternatives that can be entered into the conjugated system or π system to obtain a material that besides to be flexible, environmentally stable, presents the colored states. The revision was centred chiefly in the polypyrrole (Ppy), the polythiophene (PTh) and their derivatives such as poly (3.4-ethylenedioxythiophene) (PEDOT). The advantage of using monomers with variable structure, to adjust the composition of the copolymer, or to blend with the PC, allows to obtain a variety of colored states that can be modulated through the visible spectrum and even with applications to wavelengths outside of this region. Because the PC presented at least two different colored states can be varied continuously as a function of the voltage applied. In some cases, they may submit multicoloured statements, which offers a range of possibilities for their application in flexible electronic devices type screens and windows. Applications include smart windows, camouflage clothing and data screens. This type of material is emerging as one of the substitutes of the traditional inorganic semiconductor, with the advantage of its low cost, high flexibility and the possibility to generate multiple colors through the handling of the monomers in the structure and control of energy of his band gap. (author) [es

  20. Azadioxatriangulenium: exploring the effect of a 20 ns fluorescence lifetime in fluorescence anisotropy measurements

    Science.gov (United States)

    Bogh, Sidsel A.; Bora, Ilkay; Rosenberg, Martin; Thyrhaug, Erling; Laursen, Bo W.; Just Sørensen, Thomas

    2015-12-01

    Azaoxatriangulenium (ADOTA) has been shown to be highly emissive despite a moderate molar absorption coefficient of the primary electronic transition. As a result, the fluorescence lifetime is ~20 ns, longer than all commonly used red fluorescent organic probes. The electronic transitions in ADOTA are highly polarised (r 0  =  0.38), which in combination with the long fluorescence lifetime extents the size-range of biomolecular weights that can be detected in fluorescence polarisation-based experiments. Here, the rotational dynamics of bovine serum albumin (BSA) are monitored with three different ADOTA derivatives, differing only in constitution of the reactive linker. A detailed study of the degree of labelling, the steady-state anisotropy, and the time-resolved anisotropy of the three different ADOTA-BSA conjugates are reported. The fluorescence quantum yields (ϕ fl) of the free dyes in PBS solution are determined to be ~55%, which is reduced to ~20% in the ADOTA-BSA conjugates. Despite the reduction in ϕ fl, a ~20 ns intensity averaged lifetime is maintained, allowing for the rotational dynamics of BSA to be monitored for up to 100 ns. Thus, ADOTA can be used in fluorescence polarisation assays to fill the gap between commonly used organic dyes and the long luminescence lifetime transition metal complexes. This allows for efficient steady-state fluorescence polarisation assays for detecting binding of analytes with molecular weights of up to 100 kDa.

  1. In vitro metabolism of benzo[a]pyrene-7,8-dihydrodiol and dibenzo[def,p]chrysene-11,12 diol in rodent and human hepatic microsomes

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Jordan N.; Mehinagic, Denis; Nag, Subhasree; Crowell, Susan R.; Corley, Richard A.

    2017-03-01

    Polycyclic aromatic hydrocarbons (PAHs) are contaminants that are ubiquitously found in the environment, produced through combustion of organic matter or petrochemicals, and many of which are procarcinogens. The prototypic PAH, benzo[a]pyrene (B[a]P) and the highly carcinogenic dibenzo[def,p]chrysene (DBC) are metabolically activated by isoforms of the P450 enzyme superfamily producing benzo[a]pyrene-7,8-dihydrodiol (B[a]P diol), dibenzo[def,p]chrysene-11,12 diol (DBC diol). Each of these diols can be further metabolized by cytochrome P450 enzymes to highly reactive diol-epoxide metabolites that readily react with DNA or by phase II conjugation facilitating excretion. To complement prior in vitro metabolism studies with parent B[a]P and DBC, both phase I metabolism and phase II glucuronidation of B[a]P diol and DBC diol were measured in hepatic microsomes from female B6129SF1/J mice, male Sprague-Dawley rats, and female humans. Metabolic parameters, including intrinsic clearance and Michaelis-Menten kinetics were calculated from substrate depletion data. Mice and rats demonstrated similar B[a]P diol phase I metabolic rates. Compared to rodents, human phase I metabolism of B[a]P diol demonstrated lower overall metabolic capacity, lower intrinsic clearance at higher substrate concentrations (>0.14 µM), and higher intrinsic clearance at lower substrate concentrations (<0.07 µM). Rates of DBC diol metabolism did not saturate in mice or humans and were highest overall in mice. Higher affinity constants and lower capacities were observed for DBC diol glucuronidation compared to B[a]P diol glucuronidation; however, intrinsic clearance values for these compounds were consistent within each species. Kinetic parameters reported here will be used to extend physiologically based pharmacokinetic (PBPK) models to include the disposition of B[a]P and DBC metabolites in animal models and humans to support future human health risk assessments.

  2. Percutaneous absorption of [14C]DDT and [14C]benzo[a]pyrene from soil

    International Nuclear Information System (INIS)

    Wester, R.C.; Maibach, H.I.; Bucks, D.A.; Sedik, L.; Melendres, J.; Liao, C.; DiZio, S.

    1990-01-01

    The objective was to determine percutaneous absorption of DDT and benzo[a]pyrene in vitro and in vivo from soil into and through skin. Soil (Yolo County 65-California-57-8; 26% sand, 26% clay, 48% silt) was passed through 10-, 20-, and 48-mesh sieves. Soil then retained by 80-mesh was mixed with [14C]-labeled chemical at 10 ppm. Acetone solutions at 10 ppm were prepared for comparative analysis. Human cadaver skin was dermatomed to 500 microns and used in glass diffusion cells with human plasma as the receptor fluid (3 ml/hr flow rate) for a 24-hr skin application time. With acetone vehicle, DDT (18.1 +/- 13.4%) readily penetrated into human skin. Significantly less DDT (1.0 +/- 0.7%) penetrated into human skin from soil. DDT would not partition from human skin into human plasma in the receptor phase (less than 0.1%). With acetone vehicle, benzo[a]pyrene (23.7 +/- 9.7%) readily penetrated into human skin. Significantly less benzo[a]pyrene (1.4 +/- 0.9%) penetrated into human skin from soil. Benzo[a]pyrene would not partition from human skin into human plasma in the receptor phase (less than 0.1%). Substantivity (skin retention) was investigated by applying 14C-labeled chemical to human skin in vitro for only 25 min. After soap and water wash, 16.7 +/- 13.2% of DDT applied in acetone remained absorbed to skin. With soil only 0.25 +/- 0.11% of DDT remained absorbed to skin. After soap and water wash 5.1 +/- 2.1% of benzo[a]pyrene applied in acetone remained absorbed to skin. With soil only 0.14 +/- 0.13% of benzo[a]pyrene remained absorbed to skin

  3. Sorting fluorescent nanocrystals with DNA

    Energy Technology Data Exchange (ETDEWEB)

    Gerion, Daniele; Parak, Wolfgang J.; Williams, Shara C.; Zanchet, Daniela; Micheel, Christine M.; Alivisatos, A. Paul

    2001-12-10

    Semiconductor nanocrystals with narrow and tunable fluorescence are covalently linked to oligonucleotides. These biocompounds retain the properties of both nanocrystals and DNA. Therefore, different sequences of DNA can be coded with nanocrystals and still preserve their ability to hybridize to their complements. We report the case where four different sequences of DNA are linked to four nanocrystal samples having different colors of emission in the range of 530-640 nm. When the DNA-nanocrystal conjugates are mixed together, it is possible to sort each type of nanoparticle using hybridization on a defined micrometer -size surface containing the complementary oligonucleotide. Detection of sorting requires only a single excitation source and an epifluorescence microscope. The possibility of directing fluorescent nanocrystals towards specific biological targets and detecting them, combined with their superior photo-stability compared to organic dyes, opens the way to improved biolabeling experiments, such as gene mapping on a nanometer scale or multicolor microarray analysis.

  4. The effect of caffeine on the reactions of the excited singlet state of pyrene in micellar sodium lauryl sulfate

    Science.gov (United States)

    Hashimoto, Shuichi; Thomas, J. Kerry

    1984-08-01

    The effect of caffeine on a few photo-induced reactions of pyrene in micellar sodium lauryl sulfate (NaLS) has been studied. In these systems caffeine complexes with the pyrene (K asso = 85 ± 10 M -1 and also with the other reactants, e.g. Cu 2+ or TI +. The efficiencies of reactions which involve contact, i.e. pyrene excimer formation, and quenching by TI + ions to give the triplet state of pyrene, are significantly reduced in the presence of caffeine, due to geometric inhibitions formed by the complexation processes. The kinetics of photo-induced electron transfer, e.g. between excited pyrene and Cu 2+, are not affected. However, the subsequent reactions of the products are modified and the yield of ionic products is markedly increased.

  5. Biotransformation of the polycyclic aromatic hydrocarbon pyrene by the marine polychaete Nereis virens

    DEFF Research Database (Denmark)

    Jørgensen, Anne; Giessing, Anders M. B.; Rasmussen, Lene Juel

    2005-01-01

    In vivo and in vitro biotransformation of the polycyclic aromatic hydrocarbon (PAH) pyrene was investigated in the marine polychaete Nereis virens. Assays were designed to characterize phase I and II enzymes isolated from gut tissue. High-pressure liquid chromatography measurement of 1-hydroxypyr......In vivo and in vitro biotransformation of the polycyclic aromatic hydrocarbon (PAH) pyrene was investigated in the marine polychaete Nereis virens. Assays were designed to characterize phase I and II enzymes isolated from gut tissue. High-pressure liquid chromatography measurement of 1...

  6. Aggregation induced emission enhancement of pyrene-appended Schiff base luminophore and its photovoltaic effect

    Energy Technology Data Exchange (ETDEWEB)

    Panda, Uttam; Roy, Suman; Mallick, Debashis [Department of Chemistry, Jadavpur University, Kolkata 700032 (India); Dalapati, Pradip [Condensed Matter Physics Research Center, Department of Physics, Jadavpur University, Kolkata 700032 (India); Biswas, Subir [Immunology Lab, Department of Zoology, University of Calcutta, Kolkata 700019 (India); Manik, Nabin Baran [Condensed Matter Physics Research Center, Department of Physics, Jadavpur University, Kolkata 700032 (India); Bhattacharyya, Arindam [Immunology Lab, Department of Zoology, University of Calcutta, Kolkata 700019 (India); Sinha, Chittaranjan, E-mail: c_r_sinha@yahoo.com [Department of Chemistry, Jadavpur University, Kolkata 700032 (India)

    2016-07-15

    Pyrene appended Schiff base, 1,3-bis-((E)-pyrene-1-ylmethyleneamino)propan-2-ol (HL), a fluorophore, shows aggregation induced emission enhancement upon addition of water in DMF (4:1, v/v) solution; the quantum yield (Φ) is increased by 0.034–0.450. Under illumination of solar radiation HL (10{sup −3} M) impregnated photovoltaic cell generates 4.4 mA/6.29 V electricity. DFT and TD-DFT computation of optimized geometry of HL has explained the photophysical properties.

  7. Effects of Sludge-amendment on Mineralization of Pyrene and Microorganisms in Sludge and Soil

    DEFF Research Database (Denmark)

    Klinge, C; Gejlsbjerg, B; Ekelund, Flemming

    2001-01-01

    . Sludge-amendment enhanced the mineralization of pyrene in the soil compared to soil without sludge, and the most extensive mineralization was observed when the sludge was kept in a lump. The number of protozoa, heterotrophic bacteria and pyrene-mineralizing bacteria was much higher in the sludge compared...... to the soil. The amendment of sludge did not affect the number of protozoa and bacteria in the surrounding soil, which indicated that organic contaminants in the sludge had a little effect on the number of protozoa and bacteria in the surrounding soil...

  8. Functional properties of nisin–carbohydrate conjugates formed by radiation induced Maillard reaction

    International Nuclear Information System (INIS)

    Muppalla, Shobita R.; Sonavale, Rahul; Chawla, Surinder P.; Sharma, Arun

    2012-01-01

    Nisin–carbohydrate conjugates were prepared by irradiating nisin either with glucose or dextran. Increase in browning and formation of intermediate products was observed with a concomitant decrease in free amino and reducing sugar groups indicating occurrence of the Maillard reaction catalyzed by irradiation. Nisin–carbohydrate conjugates showed a broad spectrum antibacterial activity against Gram negative bacteria (Escherichia coli, Pseudomonas fluorescence) as well as Gram positive bacteria (Staphylococcus aureus, Bacillus cereus). Results of antioxidant assays, including that of DPPH radical-scavenging activity and reducing power, showed that the nisin–dextran conjugates possessed better antioxidant potential than nisin–glucose conjugate. These results suggested that it was possible to enhance the functional properties of nisin by preparing radiation induced conjugates suitable for application in food industry. - Highlights: ► Nisin–carbohydrate conjugates were prepared using radiation induced Maillard reaction. ► Conjugation of nisin with dextran/glucose resulted in improvement of antibacterial spectrum. ► Conjugates of nisin with dextran/glucose had significant radical scavenging activity.

  9. Syntheses and optical properties of triphenylene-containing conjugated polymers

    International Nuclear Information System (INIS)

    Chou, C.-E.; Wang Degang; Bagui, Mahuya; Hsu, Jeffrey; Chakraborty, Sanjiban; Peng Zhonghua

    2010-01-01

    In this paper, we report the detailed synthesis and optical properties of three new conjugated polymers containing triphenylene units in the backbone. Polymer PTPT exhibits strong folding propensity and forms foldamers in both polar and nonpolar solvents. PTPA, with two long alkyl chains attached to the bridging phenyl ring, exhibits mainly as interchain aggregates in 'poor' solvents (DMSO and acetonitrile), but adopts a folding conformation in solvent mixtures with a high poor solvent content. PTPV, on the other hand, adopts a random nonfolding conformation in both polar and nonpolar solvents. The low folding propensity of PTPV is likely due to the added geometrical flexibility of the vinyl bonds. Among the three polymers, PTPV is most fluorescent with a fluorescence quantum yield as high as 0.87, suggesting its potential applications as light-emitting materials or fluorescence-based sensors. PTPT, on the other hand, with its strong folding property, may find applications as efficient charge-transporting materials.

  10. Determination of Benzo[α]pyrene in Edible Oil Using Tetraoxocalix[2]arene[2]triazine Bonded Silica SPE Sorbent.

    Science.gov (United States)

    Guo, Yun; Zhao, Wen-Jie; Deng, Zhi-Fen; Hongbo, Wang; Peng, Bin; Ma, Xue; Lan, Chen; Zhang, Shu-Sheng

    2018-06-01

    Benzo[α]pyrene (BaP) is a well-known carcinogen in edible oil. In this study, a method combined solid-phase extraction (SPE) with fluorescent detection was developed using tetraoxocalix[2]arene[2]triazine sorbent (SiO 2 -OCA) for the clean-up and enrichment of BaP. The interaction between SiO 2 -OCA and BaP involves a donor-acceptor complex mechanism. The experimental procedure was as follows: BaP was extracted from edible oil with DMF/H 2 O (9:1, v/v). Then, the ratio of DMF/H 2 O was adjusted to 1:2 prior to SPE. The final concentrate was analyzed using a fluorescence detector at excitation and emission wavelengths of 255 and 420 nm. The method was fully validated. The linearity was in the range of 0.1-100 μg kg -1 with a coefficient of 0.999. The limits of detection and quantification were 0.03 and 0.1 μg kg -1 , respectively. The average recoveries were in the range of 88.0-122.3%. The intraday and interday precisions were 6.8% and 9.2%, respectively. Compared with other methods, the method reported in this article shows a good detection limit, high reproducibility and recovery, and linearity over a broad concentration range. This established method was also applied to evaluate real samples. The concentration of six tested samples was below 5 μg kg -1 .

  11. Block-conjugate-gradient method

    International Nuclear Information System (INIS)

    McCarthy, J.F.

    1989-01-01

    It is shown that by using the block-conjugate-gradient method several, say s, columns of the inverse Kogut-Susskind fermion matrix can be found simultaneously, in less time than it would take to run the standard conjugate-gradient algorithm s times. The method improves in efficiency relative to the standard conjugate-gradient algorithm as the fermion mass is decreased and as the value of the coupling is pushed to its limit before the finite-size effects become important. Thus it is potentially useful for measuring propagators in large lattice-gauge-theory calculations of the particle spectrum

  12. Prenatal induction of benzo(a)pyrene hydroxylases in mice

    International Nuclear Information System (INIS)

    Neubert, D.; Tapken, S.

    1988-01-01

    1. Benzo(a)pyrene hydroxylase (BPH) activity was measured in homogenates of fetal liver (day 18) or of whole-embryos of mice on day 9, 10 or 12 of gestation after maternal pretreatment with B(a)P on 3 consecutive days. A 3 H-liberation assay with 3 H-B(a)P labelled either generally or at the 6-position was used. The values obtained with the embryonic/fetal tissues were compared with those found in maternal liver. 2. Three oral doses of 17.5 mg B(a)P/kg body wt were found to just significantly induce BPH in maternal liver. An induction was observed after pretreatment with 24 mg B(a)P/kg body wt in 9, 10 or 12-day-old whole-embryos, but the V max reached was only 10-20% (1% on day 9) of that of adult non-induced liver. The K m (6-hydroxylation) for all tissues tested were in the same range (600-900 nM). The induction was demonstrable in embryos at tissue levels about one order of magnitude lower than those required for induction in maternal liver. 3. Treatment with 25 mg B(a)P/kg body wt on 3 consecutive days was required to induce BPH in fetal liver on day 18 of gestation. The required B(a)P tissue concentrations were about one half of those necessary for induction in maternal liver. 4. Among a variety of other polycyclic hydrocarbons only chrysene showed an inducing potency similar to that of B(a)P in adult and fetal liver. For all compounds tested there was no correlation found in the inducing potency between adult and fetal liver (e.g. coronene). 5. The doses required to induce BPH in the maternal or fetal liver or in whole embryos of rodents are significantly higher (mg range) than those of usual average human exposure or those taken up by smokers (ng range). (orig.)

  13. Fluorophore-conjugated iron oxide nanoparticle labeling and analysis of engrafting human hematopoietic stem cells

    DEFF Research Database (Denmark)

    Maxwell, Dustin J; Bonde, Jesper; Hess, David A

    2008-01-01

    culture conditions to maintain viability without inducing terminal differentiation. In the current study, fluorescent molecules were covalently linked to dextran-coated iron oxide nanoparticles (Feridex) to characterize human HSC labeling to monitor the engraftment process. Conjugating fluorophores...... to the dextran coat for fluorescence-activated cell sorting purification eliminated spurious signals from nonsequestered nanoparticle contaminants. A short-term defined incubation strategy was developed that allowed efficient labeling of both quiescent and cycling HSC, with no discernable toxicity in vitro...

  14. Fluorescence microscopy.

    Science.gov (United States)

    Sanderson, Michael J; Smith, Ian; Parker, Ian; Bootman, Martin D

    2014-10-01

    Fluorescence microscopy is a major tool with which to monitor cell physiology. Although the concepts of fluorescence and its optical separation using filters remain similar, microscope design varies with the aim of increasing image contrast and spatial resolution. The basics of wide-field microscopy are outlined to emphasize the selection, advantages, and correct use of laser scanning confocal microscopy, two-photon microscopy, scanning disk confocal microscopy, total internal reflection, and super-resolution microscopy. In addition, the principles of how these microscopes form images are reviewed to appreciate their capabilities, limitations, and constraints for operation. © 2014 Cold Spring Harbor Laboratory Press.

  15. Characterization of hapten-protein conjugates: antibody generation and immunoassay development for chlorophenoxyacetic acid pesticides.

    Science.gov (United States)

    Boro, Robin C; Singh, K Vikas; Suri, C Raman

    2009-01-01

    The generation of specific and sensitive antibodies against small molecules is greatly dependent upon the characteristics of the hapten-protein conjugates. In this study, we report a new fluorescence-based method for the characterization of hapten-protein conjugates. The method is based on an effect promoted by hapten-protein conjugation density upon the fluorescence intensity of the intrinsic tryptophan chromophore molecules of the protein. The proposed methodology is applied to quantify the hapten-protein conjugation density for two different chlorophenoxyacetic acid pesticides, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenoxybutyric acid (2,4-DB), coupled to carrier protein. Highly sensitive anti-2,4-D and anti-2,4-DB antibodies were obtained using these well-characterized hapten-protein conjugates. The generated antibodies were used in an immunoassay format demonstrating inhibitory concentration (IC50) values equal to 30 and 7 ng/mL for 2,4-D and 2,4-DB, respectively. Linearity was observed in the concentration range between 0.1-500 nglmL with LODs around 4 and 3 ng/mL for 2,4-D and 2,4-DB, respectively, in standard water samples. The proposed method was successfully applied for the determination of the extent of hapten-protein conjugation to produce specific antibodies for immunoassay development against pesticides.

  16. Entanglements in Conjugated Polymers

    Science.gov (United States)

    Xie, Renxuan; Lee, Youngmin; Aplan, Melissa; Caggiano, Nick; Gomez, Enrique; Colby, Ralph

    Conjugated polymers, such as poly(3-hexylthiophene-2,5-diyl) (P3HT) and poly-((9,9-dioctylfluorene)-2,7-diyl-alt-[4,7-bis(thiophen-5-yl)-2,1,3-benzothiadiazole]-2',2''-diyl) (PFTBT), are widely used as hole and electron transport materials in a variety of electronic devices. However, fundamental knowledge regarding chain entanglements and nematic-to-isotropic transition is still lacking and are crucial to maximize charge transport properties. A systematic melt rheology study on P3HT with various molecular weights and regio regularities was performed. We find that the entanglement molecular weight Me is 5.0 kg/mol for regiorandom P3HT, but the apparent Me for regioregular P3HT is significantly higher. The difference is postulated to arise from the presence of a nematic phase only in regioregular P3HT. Analogously, PFTBT shows a clear rheological signature of the nematic-to-isotropic transition as a reversible sharp transition at 278 C. Shearing of this nematic phase leads to anisotropic crystalline order in PFTBT. We postulate that aligning the microstructure will impact charge transport and thereby advance the field of conducting polymers. National Science Foundation.

  17. Structure and function of nanoparticle-protein conjugates

    International Nuclear Information System (INIS)

    Aubin-Tam, M-E; Hamad-Schifferli, K

    2008-01-01

    Conjugation of proteins to nanoparticles has numerous applications in sensing, imaging, delivery, catalysis, therapy and control of protein structure and activity. Therefore, characterizing the nanoparticle-protein interface is of great importance. A variety of covalent and non-covalent linking chemistries have been reported for nanoparticle attachment. Site-specific labeling is desirable in order to control the protein orientation on the nanoparticle, which is crucial in many applications such as fluorescence resonance energy transfer. We evaluate methods for successful site-specific attachment. Typically, a specific protein residue is linked directly to the nanoparticle core or to the ligand. As conjugation often affects the protein structure and function, techniques to probe structure and activity are assessed. We also examine how molecular dynamics simulations of conjugates would complete those experimental techniques in order to provide atomistic details on the effect of nanoparticle attachment. Characterization studies of nanoparticle-protein complexes show that the structure and function are influenced by the chemistry of the nanoparticle ligand, the nanoparticle size, the nanoparticle material, the stoichiometry of the conjugates, the labeling site on the protein and the nature of the linkage (covalent versus non-covalent)

  18. Solid-phase microextraction (SPME) as a tool to predict the bioavailability and toxicity of pyrene to the springtail, Folsomia candida, under various soil conditions

    DEFF Research Database (Denmark)

    Styrishave, Bjarne; Mortensen, Mads; Krogh, Paul Henning

    2008-01-01

    The porewater concentrations of pyrene were estimated by a negligible depletive solid-phase microextraction (SPME) method. The effects of organic matter (OM) and soil aging on the bioavailability of pyrene in soil were investigated by generation of reproductive effect concentrations (EC50...... increased with increasing OM and aging of the soil. The increase of the OM content in the soil reduced the extractability of pyrene by SPME, as well as the toxicity of pyrene. An aging effect was demonstrated in Askov soil, EC50 values increased with increased contact time. The amounts of pyrene extracted...

  19. Morphing hydrogel patterns by thermo-reversible fluorescence switching.

    Science.gov (United States)

    Bat, Erhan; Lin, En-Wei; Saxer, Sina; Maynard, Heather D

    2014-07-01

    Stimuli responsive surfaces that show reversible fluorescence switching behavior in response to temperature changes were fabricated. Oligo(ethylene glycol) methacrylate thermoresponsive polymers with amine end-groups were prepared by atom transfer radical polymerization (ATRP). The polymers were patterned on silicon surfaces by electron beam (e-beam) lithography, followed by conjugation of self-quenching fluorophores. Fluorophore conjugated hydrogel thin films were bright when the gels were swollen; upon temperature-induced collapse of the gels, self-quenching of the fluorophores led to significant attenuation of fluorescence. Importantly, the fluorescence was regained when the temperature was cooled. The fluorescence switching behavior of the hydrogels for up to ten cycles was investigated and the swelling-collapse was verified by atomic force microscopy. Morphing surfaces that change shape several times upon increase in temperature were obtained by patterning multiple stimuli responsive polymers. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Time-resolved fluorescence quenching studies of sodium lauryl ether sulfate micelles

    OpenAIRE

    Friedrich, Leidi C.; Silva, Volnir O.; Moreira Jr, Paulo F.; Tcacenco, Celize M.; Quina, Frank H.

    2013-01-01

    Aggregation numbers (N Ag) of micelles of the commercial anionic detergent sodium lauryl ether sulfate (SLES), with an average of two ethylene oxide subunits, were determined at 30 and 40º C by the time-resolved fluorescence quenching method with pyrene as the fluorescent probe and the N-hexadecylpyridinium ion as the quencher. The added-salt dependent growth of SLES micelles (γ = 0.11-0.15, where γ is the slope of a plot of log aggregation number vs. log [Yaq] and [Yaq] is the sodium counter...

  1. Protein carriers of conjugate vaccines

    Science.gov (United States)

    Pichichero, Michael E

    2013-01-01

    The immunogenicity of polysaccharides as human vaccines was enhanced by coupling to protein carriers. Conjugation transformed the T cell-independent polysaccharide vaccines of the past to T cell-dependent antigenic vaccines that were much more immunogenic and launched a renaissance in vaccinology. This review discusses the conjugate vaccines for prevention of infections caused by Hemophilus influenzae type b, Streptococcus pneumoniae, and Neisseria meningitidis. Specifically, the characteristics of the proteins used in the construction of the vaccines including CRM, tetanus toxoid, diphtheria toxoid, Neisseria meningitidis outer membrane complex, and Hemophilus influenzae protein D are discussed. The studies that established differences among and key features of conjugate vaccines including immunologic memory induction, reduction of nasopharyngeal colonization and herd immunity, and antibody avidity and avidity maturation are presented. Studies of dose, schedule, response to boosters, of single protein carriers with single and multiple polysaccharides, of multiple protein carriers with multiple polysaccharides and conjugate vaccines administered concurrently with other vaccines are discussed along with undesirable consequences of conjugate vaccines. The clear benefits of conjugate vaccines in improving the protective responses of the immature immune systems of young infants and the senescent immune systems of the elderly have been made clear and opened the way to development of additional vaccines using this technology for future vaccine products. PMID:23955057

  2. Applications of PDMS partitioning methods in the study of biodegradation of pyrene in the

    DEFF Research Database (Denmark)

    Tejeda-Agredano, MC; Gouliarmou, Varvara; Ortega-Calvo, JJ

    Although there are reports on the inhibition of anthropogenic organic chemicals biodegradation due to binding to dissolved humic substances (HS), there is an increasing body of evidence pointing to an enhancing effect in the case of hydrophobic chemicals, like pyrene. The addition of humic fracti...

  3. Dispersion state and humic acids concentration-dependent sorption of pyrene to carbon nanotubes

    NARCIS (Netherlands)

    Zhang, X.; Kah, M.; Jonker, M.T.O.; Hofmann, T.

    2012-01-01

    Sonication and humic acids (HA) are known to disperse carbon nanotube (CNT) suspensions, but potential effects on sorption of chemicals to CNTs remain poorly understood. We applied a passive sampling method to investigate the influence of dispersion/aggregation on sorption of pyrene to CNTs.

  4. Degradation of Polycyclic Aromatic Hydrocarbon Pyrene by Biosurfactant-Producing Bacteria Gordonia cholesterolivorans AMP 10

    Directory of Open Access Journals (Sweden)

    Tri Handayani Kurniati

    2016-12-01

    Full Text Available Pyrene degradation and biosurfactant activity by a new strain identified as Gordonia cholesterolivorans AMP 10 were studied. The strain grew well and produced effective biosurfactants in the presence of glucose, sucrose, and crude oil. The biosurfactants production was detected by the decreased surface tension of the medium and emulsification activity.  Analysis of microbial growth parameters showed that AMP10 grew best at 50 µg mL-1 pyrene concentration, leading to 96 % degradation of pyrene within 7 days. The result of nested PCR analysis revealed that this isolate possessed the nahAc gene which encodes dioxygenase enzyme for initial degradation of Polycyclic Aromatic Hydrocarbon (PAH. Observation of both tensio-active and emulsifying activities indicated that biosurfactants which produced by AMP 10 when grown on glucose could lower the surface tension of medium from 71.3 mN/m to 24.7 mN/m and formed a stable emulsion in used lubricant oil with an emulsification index (E24 of 74%. According to the results, it is suggested that the bacterial isolates G. cholesterolivorans AMP10 are suitable candidates for bioremediation of PAH-contaminated environments.How to CiteKurniati, T. H.,  Rusmana, I. Suryani, A. & Mubarik, N. R. (2016. Degradation of Polycyclic Aromatic Hydrocarbon Pyrene by Biosurfactant-Producing Bacteria Gordonia cholesterolivorans AMP 10. Biosaintifika: Journal of Biology & Biology Education, 8(3, 336-343. 

  5. Degradation of ¹³C-labeled pyrene in soil-compost mixtures and fertilized soil.

    Science.gov (United States)

    Adam, Iris K U; Miltner, Anja; Kästner, Matthias

    2015-11-01

    Polycyclic aromatic hydrocarbons (PAH) are toxic pollutants widely distributed in the environment due to natural and anthropogenic processes. In order to mitigate tar oil contaminations with PAH, research on improving bioremediation approaches, which are sometimes inefficient, is needed. However, the knowledge on the fate of PAH-derived carbon and the microbial degraders in particular in compost-supplemented soils is still limited. Here we show the PAH carbon turnover mass balance in microcosms with soil-compost mixtures or in farmyard fertilized soil using [(13)C6]-pyrene as a model PAH. Complete pyrene degradation of 100 mg/kg of soil was observed in all supplemented microcosms within 3 to 5 months, and the residual (13)C was mainly found as carbon converted to microbial biomass. Long-term fertilization of soil with farmyard manure resulted in pyrene removal efficiency similar to compost addition, although with a much longer lag phase, higher mineralization, and lower carbon incorporation into the biomass. Organic amendments either as long-term manure fertilization or as compost amendment thus play a key role in increasing the PAH-degrading potential of the soil microbial community. Phospholipid fatty acid stable isotope probing (PLFA-SIP) was used to trace the carbon within the microbial population and the amount of biomass formed from pyrene degradation. The results demonstrate that complex microbial degrader consortia rather than the expected single key players are responsible for PAH degradation in organic-amended soil.

  6. STUDYING THE INFLUENCE OF THE PYRENE INTERCALATOR TINA ON THE STABILITY OF DNA i-MOTIFS

    DEFF Research Database (Denmark)

    El-Sayed, Ahmed A.; Pedersen, Erik Bjerregaard; Khaireldin, Nahid A.

    2012-01-01

    Certain cytosine-rich (C-rich) DNA sequences can fold into secondary structures as four-stranded i-motifs with hemiprotonated base pairs. Here we synthesized C-rich TINA-intercalating oligonucleotides by inserting a nonnucleotide pyrene moiety between two C-rich regions. The stability of their i-...

  7. Patterns of 1-hydroxypyrene excretion in volunteers exposed to pyrene by the dermal route

    Energy Technology Data Exchange (ETDEWEB)

    Viau, C.; Vyskocil, A. [University of Montreal, Montreal, PQ (Canada)

    1995-02-24

    The urinary excretion profiles following exposure to pyrene were established in one psoriasic patient under treatment with a coal tar-based shampoo and in two other volunteers exposed to a single dose of 100{mu}1 creosote and, in a separate experiment, to five consecutive daily dermal applications of 500{mu}g pyrene on 200 cm{sup 2} of the inner face of the forearms. Timed micturitions were collected for up to 48 h following exposure. Both in the psoriasic patient and in the volunteers exposed to creosote, the excretion peaks between 10 and 15 h after application and first-order apparent half lives of 11.5-15 h can be calculated for the elimination phase. Compatible with these observations, repeated exposure to pyrene in the volunteers causes an increase in peak and trough urinary 1-hydroxypyrene (1-OHP) values for the first few days following the first exposure. These results suggest that the difference between beginning-of-shift/beginning of work week and beginning-of-shift/end of work week 1-OHP excretion should reflect the average exposure of the week in workers having a constant exposure to pyrene. The difference between the beginning and end-of-shift excretion values of a given day should reflect the exposure of that day but the maximum excretion would be attained a few hours after termination of exposure.

  8. Solubility of Benzo[a]pyrene and Organic Matter of Soil in Subcritical Water

    Directory of Open Access Journals (Sweden)

    Svetlana Sushkova

    2015-12-01

    Full Text Available A dynamic subcritical water extraction method of benzo[a]pyrene from soils is under consideration. The optimum conditions for benzo[a]pyrene extraction from soil are described including the soil treatment by subcritical water at 250 °C and 100 atm for 30 min. The effectiveness of developed method was determined using the matrix spiking recovery technique. A comparative analysis was made to evaluate the results of benzo[a]pyrene extraction from soils using the subcritical water and organic solvents. The advantages of the subcritical water extraction involve the use of ecologically friendly solvent, a shorter time for the analysis and a higher amount of benzo[a]pyrene extracted from soil (96 %. The influence of subcritical water extraction on soil properties was measured the investigation of the processes occurring within soil under the influence the high temperature and pressure. Under appropriate conditions of the experiment there is the destruction of the soil organic matter while the composition of the soil mineral fraction remains practically unchanged.

  9. Enzymatic synthesis of pyrene-labeled polyphosphoinositides and their behavior in organic solvents and phosphatidylcholine bilayers

    NARCIS (Netherlands)

    Gadella, Th.W.J.; Moritz, A.; Westerman, J.; Wirtz, K.W.A.

    1990-01-01

    A method is reported for the synthesis of pyrene-labeled analogues of phosphatidylinositol 4-phosphate (Pyr-PIP) and phosphatidylinositol 4,5-bisphosphate (Pyr-PIP,) from sn-2-(pyrenyl-decanoy1)phosphatidylinositol (Pyr-PI) using partially purified PI and PIP kinase preparations. Phos-phorylation of

  10. Effect of various chemicals on the metabolism of benzo(a)pyrene by cultured rat colon

    DEFF Research Database (Denmark)

    Autrup, Herman; Harris, Curtis C.; Fugaro, Steven

    1977-01-01

    The effect of various co- and anti-carcinogens of colon carcinogenesis on the metabolism of benzo(a)pyrene (BP) in cultured rat colon is reported. Rat colon enzymatically converted BP into metabolites which bind to cellular macromolecules i.e., DNA and protein. Activity of aryl hydrocarbon...

  11. On the carcinogenic polycyclic aromatic hydrocarbon benzo(a)pyrene in volcano exhausts.

    Science.gov (United States)

    Ilnitsky, A P; Belitsky, G A; Shabad, L M

    1976-05-01

    The content of benzo(a)pyrene in the juvenile ashes of the volcano Tyatya (Kunashir Island, Kuriles) and in the soil, vegetation and volcanic mud collected near volcanos in Kamchatka was studied. It was concluded that volcanic activity does not play a large role in forming the background level of this carcinogen in the human environment.

  12. Investigation of biological destruction of benzo[a]pyrene andpolycyclic aromatic hydrocarbons of biochar in soil

    Science.gov (United States)

    Okunev, R. V.; Smirnova, E. V.; Sharipova, A. R.; Gilmutdinova, I. M.; Giniyatullin, K. G.

    2018-01-01

    The biological decomposition of benzo[a]pyrene in the concentrations exceeding the MAC (maximum permissible concentration) level in soils by 2, 5 and 10 times was studied in laboratory conditions. The gray forest soil samples were contaminated with benzo[a]pyrene and incubated in optimum for bacterial growth soil moisture for 30 and 60 days. The residual amount of contaminant was monitored by HPLC after extraction with acetone-cyclohexane (2:1). Soil microbial activity was evaluated by measuring basal respiration (BR) and substrate-induced respiration (SID) rates of the soil by gas chromatography. The results of the experiment showed that in 60 days the amount of benzo[a]pyrene in contaminated soils decreased; however, this time was not enough for complete decomposition of pollutant. In this case, benzo[a]pyrene has a negative effect on the BR and SIR rates. Soil contamination affected the BR rate only at high doses (10 MPC), whereas the SIR was a more sensitive indicator of the toxic effect of the pollutant and significantly reacts already at concentrations at the level of 2 MPC. The combination of PAHs isolated from biochar has a strong negative effect on the values of BR and SIR.

  13. Excitation energy deactivation funnel in 3-substituted BODIPY-porphyrin conjugate

    International Nuclear Information System (INIS)

    Nguyen, Nguyen Tran; Verbelen, Bram; Leen, Volker; Waelkens, Etienne; Dehaen, Wim; Kruk, Mikalai

    2016-01-01

    BODIPYs absorb in the visible region which is complementary to that of porphyrins and therefore can be suggested as promising antenna groups to improve the light-harvesting potential of porphyrins. A boron-dipyrromethene dye was combined at the 3-position with a Zn-porphyrin to afford a conjugate. The fluorescence of the conjugate was found to originate from the BODIPY moiety independently of the excitation wavelength due to an unique set of energy transfer rates between the BODIPY and Zn-porphyrin moieties. The fluorescence intensity was shown to be tunable over a wide range using the solvent properties. This feature makes the studied BODIPY-porphyrin conjugate a promising compound for the design of new photochromic devices.

  14. Excitation energy deactivation funnel in 3-substituted BODIPY-porphyrin conjugate

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Nguyen Tran [Chemistry Department, University of Education, The University of DaNang, Ton Duc Thang 459, Da Nang (Viet Nam); Molecular Design and Synthesis, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven (Belgium); Verbelen, Bram; Leen, Volker [Molecular Design and Synthesis, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven (Belgium); Waelkens, Etienne [Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, Box 901, 3000 Leuven (Belgium); Dehaen, Wim, E-mail: wim.dehaen@kuleuven.be [Molecular Design and Synthesis, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven (Belgium); Kruk, Mikalai, E-mail: m.kruk@belstu.by [Belarusian State Technological University, Physics Department, Sverdlov Str., 13a, Minsk 220006 (Belarus)

    2016-11-15

    BODIPYs absorb in the visible region which is complementary to that of porphyrins and therefore can be suggested as promising antenna groups to improve the light-harvesting potential of porphyrins. A boron-dipyrromethene dye was combined at the 3-position with a Zn-porphyrin to afford a conjugate. The fluorescence of the conjugate was found to originate from the BODIPY moiety independently of the excitation wavelength due to an unique set of energy transfer rates between the BODIPY and Zn-porphyrin moieties. The fluorescence intensity was shown to be tunable over a wide range using the solvent properties. This feature makes the studied BODIPY-porphyrin conjugate a promising compound for the design of new photochromic devices.

  15. Superoxide dismutase and catalase conjugated to polyethylene glycol increases endothelial enzyme activity and oxidant resistance

    International Nuclear Information System (INIS)

    Beckman, J.S.; Minor, R.L. Jr.; White, C.W.; Repine, J.E.; Rosen, G.M.; Freeman, B.A.

    1988-01-01

    Covalent conjugation of superoxide dismutase and catalase with polyethylene glycol (PEG) increases the circulatory half-lives of these enzymes from 125 I-PEG-catalase or 125 I-PEG-superoxide dismutase produced a linear, concentration-dependent increase in cellular enzyme activity and radioactivity. Fluorescently labeled PEG-superoxide dismutase incubated with endothelial cells showed a vesicular localization. Mechanical injury to cell monolayers, which is known to stimulate endocytosis, further increased the uptake of fluorescent PEG-superoxide dismutase. Addition of PEG and PEG-conjugated enzymes perturbed the spin-label binding environment, indicative of producing an increase in plasma membrane fluidity. Thus, PEG conjugation to superoxide dismutase and catalase enhances cell association of these enzymes in a manner which increases cellular enzyme activities and provides prolonged protection from partially reduced oxygen species

  16. Probing Conformational Change of Bovine Serum Albumin–Dextran Conjugates under Controlled Dry Heating

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Shuqin; Li, Yunqi; Zhao, Qin; Li, Ji; Xia, Qiuyang; Zhang, Xiaoming; Huang, Qingrong (Rutgers); (Chinese Aca. Sci.); (Jiangnan)

    2015-04-29

    The time-dependent conformational change of bovine serum album (BSA) during Maillard reaction with dextran under controlled dry heating has been studied by small-angle X-ray scattering, fluorescence spectroscopy, dynamic light scattering, and circular dichroism analysis. Through the research on the radii of gyration (Rg), intrinsic fluorescence, and secondary structure, conjugates with dextran coating were found to inhibit BSA aggregation and preserve the secondary structure of native BSA against long-time heat treatment during Maillard reaction. The results suggested that the hydrophilic dextran was conjugated to the compact protein surface and enclosed it and more dextran chains were attached to BSA with the increase of the heating time. The study presented here will be beneficial to the understanding of the conformational evolution of BSA molecules during the dry-heating Maillard reaction and to the control of the protein–polysaccharide conjugate structure.

  17. Transfer of benzo[a]pyrene from microplastics to Artemia nauplii and further to zebrafish via a trophic food web experiment: CYP1A induction and visual tracking of persistent organic pollutants.

    Science.gov (United States)

    Batel, Annika; Linti, Frederic; Scherer, Martina; Erdinger, Lothar; Braunbeck, Thomas

    2016-07-01

    The uptake of microplastic particles and the transfer of potential harmful substances along with microplastics has been studied in a variety of organisms, especially invertebrates. However, the potential accumulation of very small microplastic particles along food webs ending with vertebrate models has not been investigated so far. Therefore, a simple artificial food chain with Artemia sp. nauplii and zebrafish (Danio rerio) was established to analyze the transfer of microplastic particles and associated persistent organic pollutants (POPs) between different trophic levels. Very small (1-20 μm) microplastic particles accumulated in Artemia nauplii and were subsequently transferred to fish. Virgin particles not loaded with POPs did not cause any observable physical harm in the intestinal tracts of zebrafish, although parts of the particles were retained within the mucus of intestinal villi and might even have been taken up by epithelial cells. The transfer of associated POPs was tested with the polycyclic aromatic hydrocarbon benzo[a]pyrene and an ethoxyresorufin-O-deethylase (EROD) assay for CYP1A induction in zebrafish liver as well as via fluorescence analyses. Whereas a significant induction in the EROD assay could not be shown, because of high individual variation and low sensitivity regarding substance concentration, the fluorescence tracking of benzo[a]pyrene indicates that food-borne microplastic-associated POPs may actually desorb in the intestine of fish and are thus transferred to the intestinal epithelium and liver. Environ Toxicol Chem 2016;35:1656-1666. © 2016 SETAC. © 2016 SETAC.

  18. Pyrene Molecular Orbital Shuffle-Controlling Excited State and Redox Properties by Changing the Nature of the Frontier Orbitals.

    Science.gov (United States)

    Merz, Julia; Fink, Julian; Friedrich, Alexandra; Krummenacher, Ivo; Al Mamari, Hamad H; Lorenzen, Sabine; Haehnel, Martin; Eichhorn, Antonius; Moos, Michael; Holzapfel, Marco; Braunschweig, Holger; Lambert, Christoph; Steffen, Andreas; Ji, Lei; Marder, Todd B

    2017-09-21

    We show that by judicious choice of substituents at the 2- and 7-positions of pyrene, the frontier orbital order of pyrene can be modified, giving enhanced control over the nature and properties of the photoexcited states and the redox potentials. Specifically, we introduced a julolidine-like moiety and Bmes 2 (mes=2,4,6-Me 3 C 6 H 2 ) as very strong donor (D) and acceptor (A), respectively, giving 2,7-D-π-D- and unsymmetric 2,7-D-π-A-pyrene derivatives, in which the donor destabilizes the HOMO-1 and the acceptor stabilizes the LUMO+1 of the pyrene core. Consequently, for 2,7-substituted pyrene derivatives, unusual properties are obtained. For example, very large bathochromic shifts were observed for all of our compounds, and unprecedented green light emission occurs for the D/D system. In addition, very high radiative rate constants in solution and in the solid state were recorded for the D-π-D- and D-π-A-substituted compounds. All compounds show reversible one-electron oxidations, and Jul 2 Pyr exhibits a second oxidation, with the largest potential splitting (ΔE=440 mV) thus far reported for 2,7-substituted pyrenes. Spectroelectrochemical measurements confirm an unexpectedly strong coupling between the 2,7-substituents in our pyrene derivatives. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Inoculating wheat (Triticum aestivum L.) with the endophytic bacterium Serratia sp. PW7 to reduce pyrene contamination.

    Science.gov (United States)

    Zhu, Xuezhu; Wang, Wanqing; Sun, Kai; Lin, Xianghao; Li, Shuang; Waigi, Michael Gatheru; Ling, Wanting

    2017-08-03

    This research was conducted to find an optimal inoculation way for a pyrene-degrading endophytic Serratia sp. PW7 to colonize wheat for reducing pyrene contamination. Three inoculation ways, which are soaking seeds in inocula (TS), dipping roots of seedlings in inocula (TR), and spraying inocula on leaves of seedlings (TL), were used in this study. Inoculated seedlings and noninoculated seedlings (CK) were, respectively, cultivated in Hoagland solutions supplemented with pyrene in a growth chamber. The results showed that strain PW7 successfully colonized the inoculated seedlings in high numbers, and significantly promoted the growth of seedlings (TS and TR). More importantly, strain PW7 reduced pyrene levels in the seedlings and the Hoagland solutions. Compared to the noninoculated seedlings, the pyrene contents of the inoculated seedlings were decreased by 35.7-86.3% in the shoots and by 26.8-60.1% in the roots after 8-day cultivation. By comparing the efficiencies of decreasing pyrene residues, it can be concluded that TR was an optimal inoculation way for endophytic strains to colonize the inoculated plants and to reduce the pyrene contamination. Our findings provide an optimized inoculation way to reduce organic contamination in crops by inoculating plants with functional endophytic bacteria.

  20. The effects of simultaneous application of plant growth regulators and bioaugmentation on improvement of phytoremediation of pyrene contaminated soils.

    Science.gov (United States)

    Rostami, Saeid; Azhdarpoor, Abooalfazl; Rostami, Majid; Samaei, Mohammad Reza

    2016-10-01

    Polycyclic aromatic hydrocarbons (PAHs) refer to a wide group of soil contaminants whose presence in the environment is a cause of concern. The present study aimed to evaluate the effects of Indole Acetic Acid (IAA) and Pseudomonas aeruginosa on the phytoremediation activities of sorghum bicolor and increase in pyrene removal efficiency in the soil. The initial concentration of pyrene was 150 and 300 mg kg(-1) in this experiment. The treatments included unplanted soil (T0), planted soil with sorghum (T1), planted soil with application of IAA (T2), planted soil with application of Pseudomonas sp. (T3), and planted soil with simultaneous application of IAA and Pseudomonas sp. (T4). The pyrene removal rate in the soil was measured every 30 days. Moreover, plant biomass and soil bacteria were measured after 90 days. The results showed that pyrene removal rate significantly increased in the planted treatments compared to the unplanted ones. After 90 days, at the initial concentration of 150-300 mg kg(-1), pyrene removal efficiency was 52-92% in T1-T4 and 35-47% in the unplanted treatment (T0). Application of IAA and Pseudomonas sp. significantly increased plant biomass, soil bacteria, and pyrene removal rate in T2, T3, and T4 compared to T1. Therefore, application of IAA in the planted treatments with sorghum could have a significant effect on increasing the removal efficiency of pyrene. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Study of Necrosis in the Liver of Formaldehyde and Benzo(αPyrene Exposured-Mice

    Directory of Open Access Journals (Sweden)

    Ahmad Soni

    2013-04-01

    Full Text Available Formaldehyde and benzo(αpyrene are compounds that harmful for health. Misapplication of this compound has an impact in the form of organ damage in the body. This study aims to determine the impact of the treatment of the combined exposure of formaldehyde and benzo(αpyrene to cell necrosis in the liver of mice (Mus musculus. Treatment of formaldehyde dose of 25 mg/kg BW to mice was given orally every day for 60 days. Treatment of benzo(αpyrene via intraperitoneal injection at a dose of 250 mg/kg BW were given after 30 days of incubation with four times injection with one day interval. Liver organ histological preparations were made through the HE staining. Observations were made by using a microscope for liver organ preparations. The data obtained that is the percentage of cells necrosis and necrotic foci. This research used Completely Randomized Design (CRD with 95% confidence interval. Liver organ preparations observations indicate that the percentage of necrosis in the untreated control, benzo(αpyrene 250 mg/kg BW, formaldehyde 25 mg/kg BW, combination of formaldehyde 25 mg/kg BW with BaP in a row that is equal to 14.43% ± 0.91; 26.05% ± 3.75; 49.38% ± 2.66; 51.86 ± 1.73. The mean of necrotic foci in liver organ formed in the untreatment control, benzo(αpyrene 250 mg/kg BW, Formaldehyde 25 mg/kg BW, and the combination of formaldehyde 25 mg/kg BW with BaP in a row, equal to 1.3 ± 0,07; 1.63 ± 0.61; 2 ± 0.51, and 3.4 ± 0.76. This suggests that the combined treatment had the highest level of toxicity compared with other treatments.

  2. Degradation of phenanthrene and pyrene using genetically engineered dioxygenase producing Pseudomonas putida in soil

    Directory of Open Access Journals (Sweden)

    Mardani Gashtasb

    2016-01-01

    Full Text Available Bioremediation use to promote degradation and/or removal of contaminants into nonhazardous or less-hazardous substances from the environment using microbial metabolic ability. Pseudomonas spp. is one of saprotrophic soil bacterium and can be used for biodegradation of polycyclic aromatic hydrocarbons (PAHs but this activity in most species is weak. Phenanthrene and pyrene could associate with a risk of human cancer development in exposed individuals. The aim of the present study was application of genetically engineered P. putida that produce dioxygenase for degradation of phenanthrene and pyrene in spiked soil using high-performance liquid chromatography (HPLC method. The nahH gene that encoded catechol 2,3-dioxygenase (C23O was cloned into pUC18 and pUC18-nahH recombinant vector was generated and transformed into wild P. putida, successfully. The genetically modified and wild types of P. putida were inoculated in soil and pilot plan was prepared. Finally, degradation of phenanthrene and pyrene by this bacterium in spiked soil were evaluated using HPLC measurement technique. The results were showed elimination of these PAH compounds in spiked soil by engineered P. putida comparing to dishes containing natural soil with normal microbial flora and inoculated autoclaved soil by wild type of P. putida were statistically significant (p0.05 but it was few impact on this process (more than 2%. Additional and verification tests including catalase, oxidase and PCR on isolated bacteria from spiked soil were indicated that engineered P. putida was alive and functional as well as it can affect on phenanthrene and pyrene degradation via nahH gene producing. These findings indicated that genetically engineered P. putida generated in this work via producing C23O enzyme can useful and practical for biodegradation of phenanthrene and pyrene as well as petroleum compounds in polluted environments.

  3. Isolation and Identification of Pyrene-degrading Bacteria from Soils around Landfills in Shiraz and Their Growth Kinetic Assay

    Directory of Open Access Journals (Sweden)

    Farshid Kafilzadeh

    2011-12-01

    Full Text Available Background & Objectives: Pyrene is a kind of carcinogen hydrocarbon in environment and one of the top 129 pollutants as ranked by the U.S.Environmental Pretection Agency (USEPA. Today's commodious method that is considered by many researchers is the use of microorganisms to degrade these compounds from the environment. The goal of this research is separation and identification of the indigenous bacterias which are effective in decomposition of Pyrene hydrocarbon from soils around Shiraz Landfills. Isolated bacteria growth in the presence of different concentrations of the aforesaid organic pollutant was evaluated. Materials & Methods: Taking samples from Landfills were done after transportation them to the laboratory. The numbers of the bacterias were counted in a medium including Pyrene 0.6 g/l and in another medium without Pyrene. The isolated bacterias were separated by the enriched medium of hydrocarbon Pyrene and were recognized accordance with standards methods (specialty of colony, microscopic properties, fermentation of sugars and biochemical test.The kinetic growth of the separated bacterias was evaluated every 12 hours during 7 successive days. Results: It was reported that the numbers of the bacterias in the medium without Pyrene is more than those with Pyrene (cfu/g. The separated bacterias were included Bacillus spp., Pseudomonas spp., Micrococcus spp., Mycobacterium spp. These four isolated bacterias showed the best growth with Pyrene 0.6 g/l during third and fourth days. Conclusion: The separating bacterias, effecting in decomposition of PAH, make this possibility that the modern methods with more efficiency to be created for removing the carcinogen organic polluters from the environment. Moreover, the separated bacterias (relating to this research can be applied to develop the microbial population in the areas that polluted with Pyrene.

  4. Conjugated Fatty Acid Synthesis

    Science.gov (United States)

    Rawat, Richa; Yu, Xiao-Hong; Sweet, Marie; Shanklin, John

    2012-01-01

    Conjugated linolenic acids (CLNs), 18:3 Δ9,11,13, lack the methylene groups found between the double bonds of linolenic acid (18:3 Δ9,12,15). CLNs are produced by conjugase enzymes that are homologs of the oleate desaturases FAD2. The goal of this study was to map the domain(s) within the Momordica charantia conjugase (FADX) responsible for CLN formation. To achieve this, a series of Momordica FADX-Arabidopsis FAD2 chimeras were expressed in the Arabidopsis fad3fae1 mutant, and the transformed seeds were analyzed for the accumulation of CLN. These experiments identified helix 2 and the first histidine box as a determinant of conjugase product partitioning into punicic acid (18:3 Δ9cis,11trans,13cis) or α-eleostearic acid (18:3 Δ9cis,11trans,13trans). This was confirmed by analysis of a FADX mutant containing six substitutions in which the sequence of helix 2 and first histidine box was converted to that of FAD2. Each of the six FAD2 substitutions was individually converted back to the FADX equivalent identifying residues 111 and 115, adjacent to the first histidine box, as key determinants of conjugase product partitioning. Additionally, expression of FADX G111V and FADX G111V/D115E resulted in an approximate doubling of eleostearic acid accumulation to 20.4% and 21.2%, respectively, compared with 9.9% upon expression of the native Momordica FADX. Like the Momordica conjugase, FADX G111V and FADX D115E produced predominantly α-eleostearic acid and little punicic acid, but the FADX G111V/D115E double mutant produced approximately equal amounts of α-eleostearic acid and its isomer, punicic acid, implicating an interactive effect of residues 111 and 115 in punicic acid formation. PMID:22451660

  5. Near-infrared (NIR) emitting conjugated polymers for biomedical applications (Presentation Recording)

    Science.gov (United States)

    Repenko, Tatjana; Kuehne, Alexander J. C.

    2015-10-01

    Fluorescent biomedical markers of today such as dye-infiltrated colloids, microgels and quantum dots suffer from fast bleaching, lack surface functionality (for targets or pharmaceutical agents) and potentially leach heavy metals in case of quantum dots (e.g. Cd). By contrast, conjugated polymer particles are non-cytotoxic, exhibit reduced bleaching, as the entire particle consists of fluorophore, they are hydrophobic and show high quantum yields. Consequently, conjugated polymer particles represent ideal materials for biological applications and imaging. However currently, conjugated polymer particles for biomedical imaging usually lack near-infrared (NIR) emission and are polydisperse. Fluorescent agents with emission in the NIR spectrum are interesting for biomedical applications due to their low photo-damage towards biological species and the ability of NIR radiation to penetrate deep into biological tissue.. I will present the development and synthesis of new conjugated polymers particles with fluorescence in the NIR spectral region for bio-imaging and clinical diagnosis. The particle synthesis proceeds in a one-step Pd or Ni-catalyzed dispersion polymerization of functional NIR emitters. The resulting monodisperse conjugated polymer particles are obtained as a dispersion in a non-hazardous solvent. Different sizes in the sub-micrometer range with a narrow size distribution can be produced. Furthermore biological recognition motifs can be easily attached to the conjugated polymers via thiol-yne click-chemistry providing specific tumor targeting without quenching of the fluorescence. References [1] Kuehne AJC, Gather MC, Sprakel J., Nature Commun. 2012, 3, 1088. [2] Repenko T, Fokong S, De Laporte L, Go D, Kiessling F, Lammers T, Kuehne AJC.,Chem Commun 2015, accepted.

  6. Liposomal Conjugates for Drug Delivery to the Central Nervous System

    Directory of Open Access Journals (Sweden)

    Frieder Helm

    2015-04-01

    Full Text Available Treatments of central nervous system (CNS diseases often fail due to the blood–brain barrier. Circumvention of this obstacle is crucial for any systemic treatment of such diseases to be effective. One approach to transfer drugs into the brain is the use of colloidal carrier systems—amongst others, liposomes. A prerequisite for successful drug delivery by colloidal carriers to the brain is the modification of their surface, making them invisible to the reticuloendothelial system (RES and to target them to specific surface epitopes at the blood–brain barrier. This study characterizes liposomes conjugated with cationized bovine serum albumin (cBSA as transport vectors in vitro in porcine brain capillary endothelial cells (PBCEC and in vivo in rats using fluorescently labelled liposomes. Experiments with PBCEC showed that sterically stabilized (PEGylated liposomes without protein as well as liposomes conjugated to native bovine serum albumin (BSA were not taken up. In contrast, cBSA-liposomes were taken up and appeared to be concentrated in intracellular vesicles. Uptake occurred in a concentration and time dependent manner. Free BSA and free cBSA inhibited uptake. After intravenous application of cBSA-liposomes, confocal fluorescence microscopy of brain cryosections from male Wistar rats showed fluorescence associated with liposomes in brain capillary surrounding tissue after 3, 6 and 24 h, for liposomes with a diameter between 120 and 150 nm, suggesting successful brain delivery of cationized-albumin coupled liposomes.

  7. Androgen Receptor Antagonism By Divalent Ethisterone Conjugates In Castrate-Resistant Prostate Cancer Cells

    Science.gov (United States)

    Levine, Paul M.; Lee, Eugine; Greenfield, Alex; Bonneau, Richard; Logan, Susan K.; Garabedian, Michael J.; Kirshenbaum, Kent

    2013-01-01

    Sustained treatment of prostate cancer with Androgen Receptor (AR) antagonists can evoke drug resistance, leading to castrate-resistant disease. Elevated activity of the AR is often associated with this highly aggressive disease state. Therefore, new therapeutic regimens that target and modulate AR activity could prove beneficial. We previously introduced a versatile chemical platform to generate competitive and non-competitive multivalent peptoid oligomer conjugates that modulate AR activity. In particular, we identified a linear and a cyclic divalent ethisterone conjugate that exhibit potent anti-proliferative properties in LNCaP-abl cells, a model of castrate-resistant prostate cancer. Here, we characterize the mechanism of action of these compounds utilizing confocal microscopy, time-resolved fluorescence resonance energy transfer, chromatin immunoprecipitation, flow cytometry, and microarray analysis. The linear conjugate competitively blocks AR action by inhibiting DNA binding. In addition, the linear conjugate does not promote AR nuclear localization or co-activator binding. In contrast, the cyclic conjugate promotes AR nuclear localization and induces cell-cycle arrest, despite its inability to compete against endogenous ligand for binding to AR in vitro. Genome-wide expression analysis reveals that gene transcripts are differentially affected by treatment with the linear or cyclic conjugate. Although the divalent ethisterone conjugates share extensive chemical similarities, we illustrate that they can antagonize the AR via distinct mechanisms of action, establishing new therapeutic strategies for potential applications in AR pharmacology. PMID:22871957

  8. pH-sensitive intracellular photoluminescence of carbon nanotube-fluorescein conjugates in human ovarian cancer cells

    International Nuclear Information System (INIS)

    Chen, M T; Ishikawa, F N; Gundersen, M A; Gomez, L M; Vernier, P T; Zhou, C

    2009-01-01

    To add to the understanding of the properties of functionalized carbon nanotubes in biological applications, we report a monotonic pH sensitivity of the intracellular fluorescence emission of single-walled carbon nanotube-fluorescein carbazide (SWCNT-FC) conjugates in human ovarian cancer cells. Light-stimulated intracellular hydrolysis of the amide linkage and localized intracellular pH changes are proposed as mechanisms. SWCNT-FC conjugates may serve as intracellular pH sensors.

  9. Research study of conjugate materials; Conjugate material no chosa kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The paper reported an introductory research on possibilities of new glass `conjugate materials.` The report took up the structure and synthetic process of conjugate materials to be researched/developed, classified them according to structural elements on molecular, nanometer and cluster levels, and introduced the structures and functions. Further, as glasses with new functions to be proposed, the paper introduced transparent and high-strength glass used for houses and vehicles, light modulation glass which realizes energy saving and optical data processing, and environmentally functional glass which realizes environmental cleaning or high performance biosensor. An initial survey was also conducted on rights of intellectual property to be taken notice of in Japan and abroad in the present situation. Reports were summed up and introduced of Osaka National Research Institute, Electrotechnical Laboratory, and National Industrial Research Institute of Nagoya which are all carrying out leading studies of conjugate materials. 235 refs., 135 figs., 6 tabs.

  10. Time-resolved fluorescence quenching studies of sodium lauryl ether sulfate micelles

    International Nuclear Information System (INIS)

    Friedrich, Leidi C.; Silva, Volnir O.; Quina, Frank H.; Moreira Junior, Paulo F.; Tcacenco, Celize M.

    2013-01-01

    Aggregation numbers (N Ag ) of micelles of the commercial anionic detergent sodium lauryl ether sulfate (SLES), with an average of two ethylene oxide subunits, were determined at 30 and 40 deg C by the time-resolved fluorescence quenching method with pyrene as the fluorescent probe and the N-hexadecylpyridinium ion as the quencher. The added-salt dependent growth of SLES micelles (γ = 0.11-0.15, where γ is the slope of a plot of log aggregation number vs. log [Y aq ] and [Y aq ] is the sodium counterion concentration free in the intermicellar aqueous phase) is found to be significantly lower than that of sodium alkyl sulfate micelles (γ ca. 0.25), a difference attributed to the larger headgroup size of SLES. The I 1 /I 3 vibronic intensity ratio and the rate constant for intramicellar quenching of pyrene show that the pyrene solubilization microenvironment and the intramicellar microviscosity are insensitive to micelle size or the presence of added salt. (author)

  11. Time-resolved fluorescence quenching studies of sodium lauryl ether sulfate micelles

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, Leidi C.; Silva, Volnir O.; Quina, Frank H., E-mail: quina@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto de Quimica; Moreira Junior, Paulo F. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Escola Politecnica. Departamento de Engenharia Quimica; Tcacenco, Celize M. [Fundacao Instituto de Ensino para Osasco (FIEO/UNIFIEO), SP (Brazil). Centro Universitario FIEO. Centro de Estudos Quimicos

    2013-02-15

    Aggregation numbers (N{sub Ag}) of micelles of the commercial anionic detergent sodium lauryl ether sulfate (SLES), with an average of two ethylene oxide subunits, were determined at 30 and 40 deg C by the time-resolved fluorescence quenching method with pyrene as the fluorescent probe and the N-hexadecylpyridinium ion as the quencher. The added-salt dependent growth of SLES micelles ({gamma} = 0.11-0.15, where {gamma} is the slope of a plot of log aggregation number vs. log [Y{sub aq}] and [Y{sub aq}] is the sodium counterion concentration free in the intermicellar aqueous phase) is found to be significantly lower than that of sodium alkyl sulfate micelles ({gamma} ca. 0.25), a difference attributed to the larger headgroup size of SLES. The I{sub 1}/I{sub 3} vibronic intensity ratio and the rate constant for intramicellar quenching of pyrene show that the pyrene solubilization microenvironment and the intramicellar microviscosity are insensitive to micelle size or the presence of added salt. (author)

  12. Conjugated polymer nanoparticles, methods of using, and methods of making

    KAUST Repository

    Habuchi, Satoshi

    2017-03-16

    Embodiments of the present disclosure provide for conjugated polymer nanoparticle, method of making conjugated polymer nanoparticles, method of using conjugated polymer nanoparticle, polymers, and the like.

  13. Conjugated polymer nanoparticles, methods of using, and methods of making

    KAUST Repository

    Habuchi, Satoshi; Piwonski, Hubert Marek; Michinobu, Tsuyoshi

    2017-01-01

    Embodiments of the present disclosure provide for conjugated polymer nanoparticle, method of making conjugated polymer nanoparticles, method of using conjugated polymer nanoparticle, polymers, and the like.

  14. Conjugated polymer zwitterions and solar cells comprising conjugated polymer zwitterions

    Science.gov (United States)

    Emrick, Todd; Russell, Thomas; Page, Zachariah; Liu, Yao

    2018-06-05

    A conjugated polymer zwitterion includes repeating units having structure (I), (II), or a combination thereof ##STR00001## wherein Ar is independently at each occurrence a divalent substituted or unsubstituted C3-30 arylene or heteroarylene group; L is independently at each occurrence a divalent C1-16 alkylene group, C6-30arylene or heteroarylene group, or alkylene oxide group; and R1 is independently at each occurrence a zwitterion. A polymer solar cell including the conjugated polymer zwitterion is also disclosed.

  15. Association to HeLa cells and surface behavior of exogenous gangliosides studied with a fluorescent derivative of GM1

    International Nuclear Information System (INIS)

    Masserini, M.; Giuliani, A.; Palestini, P.; Acquotti, D.; Pitto, M.; Chigorno, V.; Tettamanti, G.

    1990-01-01

    Cultured HeLa cells were incubated with pyrene-GM1/ 3 H-radiolabeled GM1 ganglioside (1:4 M/M) mixtures for various times. The process of association of pyrene-GM1 with cells was qualitatively and quantitatively the same as that of 3 H-GM1. The pyrene-GM1 and 3 H-GM1 proportions in the various forms of association with cells were similar to that of the starting ganglioside mixture. After 2-h incubation, the association of ganglioside with cells was well established whereas almost no metabolic processing had occurred. During a 24-h incubation, pyrene- and 3 H-GM1 underwent similar metabolic processing and gave rise to catabolic (GM2 and GM3) and anabolic (GDla) derivatives. Fluorescence spectroscopy experiments carried out with the excimer formation technique on subcellular fractions containing plasma membranes showed that exogenous ganglioside was, in part, associated with the cells in a micellar form removable by trypsin treatment, and in part inserted in a seemingly molecular dispersion. Addition of Ca 2+ salts caused aggregation of the ganglioside, as indicated by the increase of the excimer:monomer fluorescence ratio. The phenomenon was Ca 2+ concentration dependent (maximum at 10 mM), and subsequent addition of EDTA has no effect. The saccharide portion of exogenously incorporated pyrene-GM1 was available to interact with external ligands, as shown by its ability to bind cholera toxin whose addition reduced the collision rate among the ganglioside lipid moieties

  16. Self-assembled fluorescent organic nanoparticles for live cell imaging

    NARCIS (Netherlands)

    Fischer, I.; Petkau, K.; Dorland, Y.L.; Schenning, A.P.H.J.; Brunsveld, L.

    2013-01-01

    Fluorescent, cell-permeable, organic nanoparticles based on self-assembled p-conjugated oligomers with high absorption cross-sections and high quantum yields have been developed. The nanoparticles are generated with a tuneable density of amino groups for charge-mediated cellular uptake by a

  17. Fluorescent magnetic hybrid nanoprobe for multimodal bioimaging

    Energy Technology Data Exchange (ETDEWEB)

    Koktysh, Dmitry [Department of Chemistry, Vanderbilt University, Station B 351822, Nashville, TN 37235 (United States); Bright, Vanessa; Pham, Wellington, E-mail: dmitry.koktysh@vanderbilt.edu, E-mail: wellington.pham@vanderbilt.edu [Institute of Imaging Science, Vanderbilt University, 1161 21st Avenue South AA, 1105 MCN, Nashville, TN 37232 (United States)

    2011-07-08

    A fluorescent magnetic hybrid imaging nanoprobe (HINP) was fabricated by the conjugation of superparamagnetic Fe{sub 3}O{sub 4} nanoparticles and visible light emitting ({approx}600 nm) fluorescent CdTe/CdS quantum dots (QDs). The assembly strategy used the covalent linking of the oxidized dextran shell of magnetic particles to the glutathione ligands of QDs. The synthesized HINP formed stable water-soluble colloidal dispersions. The structure and properties of the particles were characterized by transmission electron and atomic force microscopy, energy dispersive x-ray analysis and inductively coupled plasma optical emission spectroscopy, dynamic light scattering analysis, optical absorption and photoluminescence spectroscopy, and fluorescent imaging. The luminescence imaging region of the nanoprobe was extended to the near-infrared (NIR) ({approx}800 nm) by conjugation of the superparamagnetic nanoparticles with synthesized CdHgTe/CdS QDs. Cadmium, mercury based QDs in HINP can be easily replaced by novel water-soluble glutathione stabilized AgInS{sub 2}/ZnS QDs to present a new class of cadmium-free multimodal imaging agents. The observed NIR photoluminescence of fluorescent magnetic nanocomposites supports their use for bioimaging. The developed HINP provides dual-imaging channels for simultaneous optical and magnetic resonance imaging.

  18. Ratiometric Sensing of Hydrogen Peroxide Utilizing Conformational Change in Fluorescent Boronic Acid Polymers

    Directory of Open Access Journals (Sweden)

    Kan Takeshima

    2017-01-01

    Full Text Available We demonstrate that the copolymers containing boronic acid and pyrene units can be utilized for the fluorometric sensing of hydrogen peroxide (H2O2 in aqueous solutions. The copolymer exists in a relatively extended conformation in the absence of H2O2, whereas the polymer chain is contracted by the reaction of boronic acid moieties with H2O2 to form phenol groups. This conformational change induces aggregation of the originally isolated pyrene groups. As a result, relative intensity of excimer emission with respect to monomer emission increases with H2O2 concentration. Accordingly, the present methodology enables us to measure H2O2 by means of ratiometric fluorescence change in the range of 0–30 μM.

  19. Influence of particle characteristics and organic matter content on the bioavailability and bioaccumulation of pyrene by clams

    International Nuclear Information System (INIS)

    Verrengia Guerrero, N.R.; Taylor, M.G.; Wider, E.A.; Simkiss, K.

    2003-01-01

    An experimental model with artificial particles and humic acids describes bioavailability of sediment-bound pyrene to clams. - Hydrophobic chemicals are known to associate with sediment particles including those from both suspended particulate matter and bottom deposits. The complex and variable composition of natural particles makes it very difficult therefore, to predict the bioavailability of sediment-bound contaminants. To overcome these problems we have previously devised a test system using artificial particles, with or without humic acids, for use as an experimental model of natural sediments. In the present work we have applied this experimental technique to investigate the bioavailability and bioaccumulation of pyrene by the freshwater fingernail clam Sphaerium corneum. The uptake and accumulation of pyrene in clams exposed to the chemical in the presence of a sample of natural sediment was also investigated. According to the results obtained, particle surface properties and organic matter content are the key factors for assessing the bioavailability and bioaccumulation of pyrene by clams

  20. Topological analysis of the electron density and of the electron localization function of pyrene and its radicals

    International Nuclear Information System (INIS)

    Hernandez-Trujillo, Jesus; Garcia-Cruz, Isidoro; Martinez-Magadan, Jose Manuel

    2005-01-01

    The topological properties of the charge distribution of pyrene and the three derived monoradicals in their ground state and of didehydrogenated pyrenes in the lowest singlet and triplet electronic states are discussed in detail by means of the quantum theory of atoms in molecules (TAIM) and by the electron localization function (ELF). The non-equivalence of the fused aromatic rings of pyrene prevents one from anticipating the stability and reactivity of these species from the chemistry of didehydrogenated species derived from benzene only. Whereas some of these didehydrogenated molecules were found to display a diradical character in the singlet ground state, the topological analysis reveals that others correspond to normal closed shells. Using these theoretical tools, the energetic and geometric details of o-, m- and p-benzyne-like pyrene derivatives are explained

  1. Transplantation of hamster lung lesions induced by 239PuO2 or benz(a)pyrene

    International Nuclear Information System (INIS)

    McDonald, K.E.; Sanders, C.L.

    1980-01-01

    None(0%) of 1000 recipients of lung lesions for 239 PuO 2 -exposed hamsters that were transplanted into other hamsters' cheek pouches, developed tumors, whereas 90% of transplants from benz(a)pyrene-induced lung lesions were malignant

  2. Association between mutation spectra and stable and unstable DNA adduct profiles in Salmonella for benzo[a]pyrene and dibenzo[a,l]pyrene

    Energy Technology Data Exchange (ETDEWEB)

    DeMarini, David M., E-mail: demarini.david@epa.gov [Integrated Systems Toxicology Division, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Hanley, Nancy M.; Warren, Sarah H.; Adams, Linda D.; King, Leon C. [Integrated Systems Toxicology Division, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States)

    2011-09-01

    Highlights: {yields} Benzo[a]pyrene (BP) induces stable DNA adducts and mutations primarily at guanine. {yields} Dibenzo[a,l]pyrene (DBP) induces them primarily at adenine. {yields} BP induces abasic sites, but DBP does not in the Salmonella mutagenicity assay. {yields} Stable DNA adducts alone appear to account for the mutation spectrum of DBP. {yields} Stable DNA adducts and possibly abasic sites account for the mutation spectrum of BP. - Abstract: Benzo[a]pyrene (BP) and dibenzo[a,l]pyrene (DBP) are two polycyclic aromatic hydrocarbons (PAHs) that exhibit distinctly different mutagenicity and carcinogenicity profiles. Although some studies show that these PAHs produce unstable DNA adducts, conflicting data and arguments have been presented regarding the relative roles of these unstable adducts versus stable adducts, as well as oxidative damage, in the mutagenesis and tumor-mutation spectra of these PAHs. However, no study has determined the mutation spectra along with the stable and unstable DNA adducts in the same system with both PAHs. Thus, we determined the mutagenic potencies and mutation spectra of BP and DBP in strains TA98, TA100 and TA104 of Salmonella, and we also measured the levels of abasic sites (aldehydic-site assay) and characterized the stable DNA adducts ({sup 32}P-postlabeling/HPLC) induced by these PAHs in TA104. Our results for the mutation spectra and site specificity of stable adducts were consistent with those from other systems, showing that DBP was more mutagenic than BP in TA98 and TA100. The mutation spectra of DBP and BP were significantly different in TA98 and TA104, with 24% of the mutations induced by BP in TA98 being complex frameshifts, whereas DBP produced hardly any of these mutations. In TA104, BP produced primarily GC to TA transversions, whereas DBP produced primarily AT to TA transversions. The majority (96%) of stable adducts induced by BP were at guanine, whereas the majority (80%) induced by DBP were at adenine

  3. Spirolactone and spirothiolactone rhodamine-pyrene probes for detection of Hg²⁺ with different sensing properties and its application in living cells.

    Science.gov (United States)

    Rui, Qing-Qing; Zhou, Yi; Fang, Yuan; Yao, Cheng

    2016-04-15

    Two new rhodamine B-based fluorescent probes PyRbS and PyRbO containing pyrene moiety were designed and synthesized. Both of the probes showed colorimetric and fluorometric sensing abilities for Hg(2+) with high selectivity over other metal ions. The binding analysis using Job's plot suggested 1:1 stoichiometry for the complexes formed for Hg(2+). Compared with PyRbO, the PyRbS showed higher selectivity and sensitivity due to the thiophilic property of Hg(2+) ion. The PyRbS exhibited the linear fluorescence quenching to Hg(2+) in the range of 0.3 to 4.8 μM (λ(ex)=365 nm) and 0.3 to 5.4 μM (λ(ex)=515 nm), and the detection limit was 0.72 μM. Moreover, ratiometric changes of PyRbS with Hg(2+) in absorption spectrum were observed, which could not be obtained in the combination of PyRbO with Hg(2+). In addition, the methyl thiazolyl tetrazolium (MTT) assay demonstrated that RbPyS had low cytotoxicity and was successfully used to monitor intracellular Hg(2+) levels in living cells. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. A novel baseline-correction method for standard addition based derivative spectra and its application to quantitative analysis of benzo(a)pyrene in vegetable oil samples.

    Science.gov (United States)

    Li, Na; Li, Xiu-Ying; Zou, Zhe-Xiang; Lin, Li-Rong; Li, Yao-Qun

    2011-07-07

    In the present work, a baseline-correction method based on peak-to-derivative baseline measurement was proposed for the elimination of complex matrix interference that was mainly caused by unknown components and/or background in the analysis of derivative spectra. This novel method was applicable particularly when the matrix interfering components showed a broad spectral band, which was common in practical analysis. The derivative baseline was established by connecting two crossing points of the spectral curves obtained with a standard addition method (SAM). The applicability and reliability of the proposed method was demonstrated through both theoretical simulation and practical application. Firstly, Gaussian bands were used to simulate 'interfering' and 'analyte' bands to investigate the effect of different parameters of interfering band on the derivative baseline. This simulation analysis verified that the accuracy of the proposed method was remarkably better than other conventional methods such as peak-to-zero, tangent, and peak-to-peak measurements. Then the above proposed baseline-correction method was applied to the determination of benzo(a)pyrene (BaP) in vegetable oil samples by second-derivative synchronous fluorescence spectroscopy. The satisfactory results were obtained by using this new method to analyze a certified reference material (coconut oil, BCR(®)-458) with a relative error of -3.2% from the certified BaP concentration. Potentially, the proposed method can be applied to various types of derivative spectra in different fields such as UV-visible absorption spectroscopy, fluorescence spectroscopy and infrared spectroscopy.

  5. Systemic excretion of benzo(a)pyrene in the control and microsomally induced rat: the influence of plasma lipoproteins and albumin as carrier molecules

    International Nuclear Information System (INIS)

    Shu, H.P.; Bymun, E.N.

    1983-01-01

    In vitro studies have previously indicated that benzo(a)pyrene distributes primarily into the plasma lipoprotein fraction when incubated with whole plasma. Hydroxylated metabolites of benzo(a)pyrene distribute increasingly into the albumin fraction as the degree of metabolite hydroxylation increases. This report assesses the influence of plasma lipoproteins and albumin as carriers for benzo(a)pyrene on carcinogen excretion in the control and microsomally induced rat. Male Sprague-Dawley rats cannulated in the bile duct received i.v. injections of radiolabeled benzo(a)pyrene noncovalently bound to the very-low-density, low-density, or high-density lipoproteins in equimolar amounts. Bile was collected and measured for radioactivity. Cumulative biliary excretions of benzo(a)pyrene complexed with rat lipoproteins were 39.6 +/- 9.7 (S.D.), 24.6 +/- 1.3, and 21.2 +/- 8.8% for very low-density, low-density, and high-density lipoprotein, respectively. Values for excretion of benzo(a)pyrene complexed with rat or human lipoproteins were comparable. These data suggest that the transport molecule can effect a 2-fold difference in benzo(a)pyrene excretion under conditions of the present study. Thus, excretion increased as the degree of benzo(a)pyrene hydroxylation increased. The effect of microsomal enzyme induction on excretion of lipoprotein-bound benzo(a)pyrene was also assessed. Contrary to expectation, excretion of benzo(a)pyrene bound to the very-low-density, low-density, or high-density lipoproteins in Aroclor-induced rats was not greater than that of control animals. Hence, under the conditions of the present study, 60 to 80% of the injected benzo(a)pyrene and 50 to 60% of the injected benzo(a)pyrene metabolites were not excreted immediately in control or microsomally induced animals. This benzo(a)pyrene may represent a carcinogen pool that is slowly excreted

  6. Phthalic acid and benzo[a]pyrene in soil-plant-water systems amended with contaminated sewage sludge

    DEFF Research Database (Denmark)

    Mougin, C.; Dappozze, F.; Brault, A.

    2006-01-01

    We studied the fate of C-14-labelled phthalic acid and benzo[a]pyrene applied to the soil by the way of contaminated sewage sludge in model ecosystems allowing the simultaneous assessment of physicochemical and biological descriptors. Here we show that the mineralisation of phthalic acid is highe......[a]pyrene is recalcitrant to biodegradation whatever the type of soil contamination. We show also that the chemicals present in the sludge are poorly transferred to soil leachates and plant seedlings....

  7. Gambaran Histopatologik Payudara Mencit (Mus Musculus) Yang Diinduksi Benzo(α)pyrene Dan Diberikan Ekstrak Kunyit (Curcuma Longa L.)

    OpenAIRE

    Nansi, Eka M; Durry, Meilany F; Kairupan, Carla

    2015-01-01

    : Breast cancer (Carcinoma mammae) is one of the most common cancers affecting women. The etiology of breast cancer is still unknown, however, there are several important risk factors linked to the occurence of breast cancer, as follows: genetic, hormonal, and environmental. Polycyclic aromatic hydrocarbons (PHA) such as benzo(a)pyrene is a carcinogenic agent that can be found in the surrounding environment. It has been proven that benzo(a)pyrene can induce tumors in experimental animal model...

  8. High-efficiency pyrene-based blue light emitting diodes: Aggregation suppression using a calixarene 3D-scaffold

    KAUST Repository

    Chan, Khaileok

    2012-01-01

    An efficient blue light emitting diode based on solution processable pyrene-1,3-alt-calix[4]arene is demonstrated, providing a record current efficiency of 10.5 cd A -1 in a simple non-doped OLED configuration. Complete suppression of pyrene aggregation in the solid state is achieved by controlling chromophore dispersion using the 1,3-alt-calix[4]arene scaffold. © 2012 The Royal Society of Chemistry.

  9. Effect of bioaugmentation to enhance phytoremediation for removal of phenanthrene and pyrene from soil with Sorghum and Onobrychis sativa

    Science.gov (United States)

    2014-01-01

    The use of plants to remove Poly-aromatic-hydrocarbons (PAHs) from soil (phytoremediation) is emerging as a cost-effective method. Phytoremediation of contaminated soils can be promoted by the use of adding microorganisms with the potential of pollution biodegradation (bioaugmentation). In the present work, the effect of bacterial consortium was studied on the capability of Sorghum and Onobrychis sativa for the phytoremediation of soils contaminated with phenanthrene and pyrene. 1.5 kg of the contaminated soil in the ratio of 100 and 300 mg phenanthrene and/or pyrene per kg of dry soil was then transferred into each pot (nine modes). The removal efficiency of natural, phytoremediation and bioaugmentation, separately and combined, were evaluated. The samples were kept under field conditions, and the remaining concentrations of pyrene and phenanthrene were determined after 120 days. The rhizosphere as well as the microbial population of the soil was also determined. Results indicated that both plants were able to significantly remove pyrene and phenanthrene from the contaminated soil samples. Phytoremediation alone had the removal efficiency of about 63% and 74.5% for pyrene and phenanthrene respectively. In the combined mode, the removal efficiency dramatically increased, leading to pyrene and phenanthrene removal efficiencies of 74.1% and 85.02% for Onobrychis sativa and 73.84% and 85.2% for sorghum, respectively. According to the results from the present work, it can be concluded that Onobrychis sativa and sorghum are both efficient in removing pyrene and phenanthrene from contamination and bioaugmentation can significantly enhance the phytoremediation of soils contaminated with pyrene and phenanthrene by 22% and 16% respectively. PMID:24406158

  10. Fluorescein Derivatives in Intravital Fluorescence Imaging

    Directory of Open Access Journals (Sweden)

    Michael S. Roberts

    2013-08-01

    Full Text Available Intravital fluorescence microscopy enables the direct imaging of fluorophores in vivo and advanced techniques such as fluorescence lifetime imaging (FLIM enable the simultaneous detection of multiple fluorophores. Consequently, it is now possible to record distribution and metabolism of a chemical in vivo and to optimise the delivery of fluorophores in vivo. Recent clinical applications with fluorescein and other intravital fluorescent stains have occurred in neurosurgery, dermatology [including photodynamic therapy (PDT] and endomicroscopy. Potential uses have been identified in periodontal disease, skin graft and cancer surgery. Animal studies have demonstrated that diseased tissue can be specifically stained with fluorophore conjugates. This review focuses on the fluorescein derived fluorophores in common clinical use and provides examples of novel applications from studies in tissue samples.

  11. Photoacoustic emission from fluorescent nanodiamonds enhanced with gold nanoparticles

    Science.gov (United States)

    Zhang, Bailin; Fang, Chia-Yi; Chang, Cheng-Chun; Peterson, Ralph; Maswadi, Saher; Glickman, Randolph D.; Chang, Huan-Cheng; Ye, Jing Yong

    2012-01-01

    Fluorescent nanodiamonds (FNDs) have drawn much attention in recent years for biomedical imaging applications due to their desired physical properties including excellent photostability, high biocompatibility, extended far-red fluorescence emission, and ease of surface functionalization. Here we explore a new feature of FNDs, i.e. their photoacoustic emission capability, which may lead to potential applications of using FNDs as a dual imaging contrast agent for combined fluorescence and photoacoustic imaging modalities. We observed significant enhancement of photoacoustic emission from FNDs when they were conjugated with gold nanoparticles (GNPs). PMID:22808436

  12. Photoacoustic emission from fluorescent nanodiamonds enhanced with gold nanoparticles.

    Science.gov (United States)

    Zhang, Bailin; Fang, Chia-Yi; Chang, Cheng-Chun; Peterson, Ralph; Maswadi, Saher; Glickman, Randolph D; Chang, Huan-Cheng; Ye, Jing Yong

    2012-07-01

    Fluorescent nanodiamonds (FNDs) have drawn much attention in recent years for biomedical imaging applications due to their desired physical properties including excellent photostability, high biocompatibility, extended far-red fluorescence emission, and ease of surface functionalization. Here we explore a new feature of FNDs, i.e. their photoacoustic emission capability, which may lead to potential applications of using FNDs as a dual imaging contrast agent for combined fluorescence and photoacoustic imaging modalities. We observed significant enhancement of photoacoustic emission from FNDs when they were conjugated with gold nanoparticles (GNPs).

  13. Investigation on the photocatalytic degradation of pyrene on soil surfaces using nanometer anatase TiO2 under UV irradiation

    International Nuclear Information System (INIS)

    Dong Dianbo; Li Peijun; Li Xiaojun; Zhao Qing; Zhang Yinqiu; Jia Chunyun; Li Peng

    2010-01-01

    Photocatalytic degradation of pyrene on soil surfaces was investigated in the presence of nanometer anatase TiO 2 under a variety of conditions. After being spiked with pyrene, soil samples loaded with different amounts of TiO 2 (0%, 1%, 2%, 3%, and 4%, w/w) were exposed to UV irradiation for 25 h. The results indicated that the photocatalytic degradation of pyrene followed pseudo-first-order kinetics. TiO 2 accelerated the degradation of pyrene generally as indicated by the half-life reduction from 45.90 to 31.36 h, corresponding to the TiO 2 amounts from 0% to 4%, respectively. The effects of H 2 O 2 , light intensity and humic acids on the degradation of pyrene were also investigated. The degradation of pyrene increased along with increasing the concentration of H 2 O 2 , light intensity and the concentration of humic acids. All results indicated that the photocatalytic method in the presence of nanometer anatase TiO 2 was an advisable choice for the treatments of PAHs polluted soil in the future.

  14. Reactions of model compounds in the presence of pyrene and MoS sub 2 to simulate coprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Ting, P.-S.; Curtis, C.W.; Cronauer, D.C. (Auburn University, Auburn, AL (USA). Chemical Engineering Dept.)

    Catalytic reactions of pyrene using in situ generated MoS{sub 2} from molybdenum naphthenate and excess sulfur were evaluated in the presence of added model species, both hydrocarbons and heteroatomic species. The added hydrocarbons and heteroatomic compounds containing oxygen and sulfur had little effect on the hydrogenation of pyrene at either 400 or 425{degree}C, but quinoline at 400{degree}C reduced the hydrogenation of pyrene by half. Reactions at 425{degree}C also reduced the hydrogenation of pyrene by half regardless of the added model species. The added model species underwent different degrees of reaction: the hydrocarbons underwent little or no reaction, dibenzofuran showed little hydrodeoxygenation, dibenzothiophene yielded substantial hydrodesulfurization and quinoline was almost totally hydrodenitrogenated. The addition of quinoline at increasing concentration resulted in substantial lowering of pyrene hydrogenation and quinoline hydrodenitrogenation. Introduction of quinoline at a low concentration of 0.4 wt% gave a pyrene hydrogenation rate constant of 0.073 min{sup -1} at 400{degree}C while an increase in quinoline to 10.0 wt% yielded a rate constant of 0.020 min{sup -1}. 21 refs., 7 figs., 6 tabs.

  15. Effects of Nereis diversicolor on the Transformation of 1-Methylpyrene and Pyrene

    DEFF Research Database (Denmark)

    Malmquist, Linus Mattias Valdemar; Christensen, Jan Henning; Selck, Henriette

    and quantitative analyses of metabolites and parent compounds in worm tissue, water, and sediment were performed. Transformation of 1-methylpyrene generated the benzylic hydroxylated phase I product, 1-pyrenecarboxylic acid that comprised 90% of the total metabolites of 1-methylpyrene, and was mainly found......Transformation of nonsubstituted and alkyl-substituted polycyclic aromatic hydrocarbons (PAHs) by the benthic invertebrate Nereis diversicolor was compared in this study. Pyrene and 1-methylpyrene were used as model compounds for nonsubstituted and alkyl-substituted PAHs, respectively. Qualitative...... as the most prominent metabolite. Transformation of 1-methylpyrene (21% transformed) was more than 3 times as efficient as pyrene transformation (5.6% transformed). Because crude oils contain larger amounts of C1−C4-substituted PAHs than nonsubstituted PAHs, the rapid and efficient transformation of sediment...

  16. Effects of Nereis diversicolor on the transformation of 1-Methylpyrene and Pyrene

    DEFF Research Database (Denmark)

    Malmquist, Linus Mattias Valdemar; Christensen, Jan H.; Selck, Henriette

    2013-01-01

    and quantitative analyses of metabolites and parent compounds in worm tissue, water, and sediment were performed. Transformation of 1-methylpyrene generated the benzylic hydroxylated phase I product, 1-pyrenecarboxylic acid that comprised 90% of the total metabolites of 1-methylpyrene, and was mainly found......Transformation of nonsubstituted and alkyl-substituted polycyclic aromatic hydrocarbons (PAHs) by the benthic invertebrate Nereis diversicolor was compared in this study. Pyrene and 1-methylpyrene were used as model compounds for nonsubstituted and alkyl-substituted PAHs, respectively. Qualitative...... as the most prominent metabolite. Transformation of 1-methylpyrene (21% transformed) was more than 3 times as efficient as pyrene transformation (5.6% transformed). Because crude oils contain larger amounts of C1−C4-substituted PAHs than nonsubstituted PAHs, the rapid and efficient transformation of sediment...

  17. Transtuzumab-conjugated liposome-coated fluorscent magnetic namoparticles to target breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Mi Jung; Lee, Hak Jong; Hwang, Sung Il; Yun, Bo La; Kim, Sun Mi [Dept. of Radiology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Yoon, Young Il; Kwon, Yong Soo [Nanoimaging and Therapy Research Center, Institute of Nanoconvergence, Advanced Institutes of Convergence Technology, Seoul National University, Suwon (Korea, Republic of); Yoon, Tae Jong [NanoBio Materials Chemistry Lab., Dept. of Applied Bioscience, CHA University, Pocheon (Korea, Republic of)

    2014-08-15

    To synthesize mesoporous silica-core-shell magnetic nanoparticles (MNPs) encapsulated by liposomes (Lipo [MNPm-SiO{sub 2}]) in order to enhance their stability, allow them to be used in any buffer solution, and to produce trastuzumab-conjugated (Lipo[MNPm-SiO{sub 2}]-Her2Ab) nanoparticles to be utilized in vitro for the targeting of breast cancer. The physiochemical characteristics of Lipo[MNPm-SiO{sub 2}] were assessed in terms of size, morphological features, and in vitro safety. The multimodal imaging properties of the organic dye incorporated into Lipo[MNPm-SiO{sub 2}] were assessed with both in vitro fluorescence and MR imaging. The specific targeting ability of trastuzumab (Her2/neu antibody, Herceptin)-conjugated Lipo[MNPm-SiO{sub 2}] for Her2/neu-positive breast cancer cells was also evaluated with fluorescence and MR imaging. We obtained uniformly-sized and evenly distributed Lipo[MNPm-SiO{sub 2}] that demonstrated biological stability, while not disrupting cell viability. Her2/neu-positive breast cancer cell targeting by trastuzumab-conjugated Lipo[MNPm-SiO{sub 2}] was observed by in vitro fluorescence and MR imaging. Trastuzumab-conjugated Lipo[MNPm-SiO{sub 2}] is a potential treatment tool for targeted drug delivery in Her2/neu-positive breast cancer.

  18. Conjugation of nano and quantum materials with bovine serum albumin (BSA) to study their biological potential

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Suman, E-mail: sumansingh01@gmail.com [Central Scientific Instruments Organisation (CSIR-CSIO), Chandigarh (India); Kaur, Rajnish; Chahal, Jitender; Devi, P. [Central Scientific Instruments Organisation (CSIR-CSIO), Chandigarh (India); Jain, D.V.S. [Panjab University, Chandigarh (India); Singla, M.L., E-mail: singla_min@yahoo.co.in [Central Scientific Instruments Organisation (CSIR-CSIO), Chandigarh (India)

    2013-09-15

    Conjugates of gold nanoparticles (AuNPs) and semiconductor quantum dots (CdS/T) have been synthesized with bovine serum albumin (BSA) using wet chemistry. The optical properties of nano and quantum materials and their BSA conjugate have been studied using UV–Visible and Fluorescence spectroscopy. UV–Visible spectrum of pure BSA showed an absorption maximum at 278 nm, which showed blue shift after its conjugation with nano and quantum materials. Increased concentration of AuNPs during conjugation resulted in broadening of BSA peak (278 nm), which can be related to the formation of ground state complex formation, caused by the partial adsorption of BSA on the surface of NPs. However, increased concentrations of BSA resulted in decrease in SPR intensity of gold nanoparticles (528 nm) and absorbance peak of BSA started diminishing. AuNPs acted as quencher for BSA fluorescence intensity, when excited at 280 nm. The binding constant (K) and the number of binding sites (n) between AuNPs and BSA have been found to be 1.97×10{sup 2} LM{sup −1} and 0.6 respectively. With quantum dots, conjugation resulted in enhancement of fluorescence emission of quantum dots when excited at 300 nm, which might be due to the stabilizing effect of BSA on QDs or due to energy transfer from tryptophan moieties of albumin to quantum dots. -- Highlights: • Synthesis of nanoparticles (AuNPs) and quantum dots (CdS). • Conjugation of these materials with bovine serum albumin. • Optical behavioral studies.

  19. Degradation of pyrene in soil and in vitro by a Bacillus lentus strain ...

    African Journals Online (AJOL)

    A bacterium isolated from an asphalt plant soil and identified as a strain of Bacillus lentus was tested in vitro and in sterilized and native soils for ability to survive and sustain pyrene degradation over a period of 63 days. The exponential growth rate in vitro was 0.049 d-1 and the doubling time 2.65 d. In the control flask ...

  20. Chemoresistance to Cancer Treatment: Benzo-α-Pyrene as Friend or Foe?

    Science.gov (United States)

    Dzobo, Kevin; Hassen, Naseeha; Senthebane, Dimakatso Alice; Thomford, Nicholas Ekow; Rowe, Arielle; Shipanga, Hendrina; Wonkam, Ambroise; Parker, M Iqbal; Mowla, Shaheen; Dandara, Collet

    2018-04-17

    Background: Environmental pollution such as exposure to pro-carcinogens including benzo-α-pyrene is becoming a major problem globally. Moreover, the effects of benzo-α-pyrene (BaP) on drug pharmacokinetics, pharmacodynamics, and drug resistance warrant further investigation, especially in cancer outpatient chemotherapy where exposure to environmental pollutants might occur. Method: We report here on the effects of benzo-α-pyrene on esophageal cancer cells in vitro, alone, or in combination with chemotherapeutic drugs cisplatin, 5-flurouracil, or paclitaxel. As the study endpoints, we employed expression of proteins involved in cell proliferation, drug metabolism, apoptosis, cell cycle analysis, colony formation, migration, and signaling cascades in the WHCO1 esophageal cancer cell line after 24 h of treatment. Results: Benzo-α-pyrene had no significant effect on WHCO1 cancer cell proliferation but reversed the effect of chemotherapeutic drugs by reducing drug-induced cell death and apoptosis by 30–40% compared to drug-treated cells. The three drugs significantly reduced WHCO1 cell migration by 40–50% compared to control and BaP-treated cells. Combined exposure to drugs was associated with significantly increased apoptosis and reduced colony formation. Evaluation of survival signaling cascades showed that although the MEK-ERK and Akt pathways were activated in the presence of drugs, BaP was a stronger activator of the MEK-ERK and Akt pathways than the drugs. Conclusion: The present study suggest that BaP can reverse the effects of drugs on cancer cells via the activation of survival signaling pathways and upregulation of anti-apoptotic proteins such as Bcl-2 and Bcl-xL. Our data show that BaP contribute to the development of chemoresistant cancer cells.

  1. Benzo(a)pyrene activation and detoxification by human pulmonary alveolar macrophages and lymphocytes

    International Nuclear Information System (INIS)

    Marshall, M.V.; McLemore, T.L.; Martin, R.R.; Marshall, M.H.; Wray, N.P.; Busbee, D.L.; Cantrell, E.T.; Arnott, M.S.; Griffin, A.C.

    1980-01-01

    Comparisons of pulmonary alveolar macrophages and circulating lymphocytes from five smokers and five nonsmokers for their ability to metabolize benzo(a)pyrene as determined by high pressure liquid chromatography were carried out. Utilizing this approach, further investigation of activation and detoxification by several human cell types could provide the basis for more precise and comprehensive studies of carcinogen and drug metabolism in the human lung, and for a better assessment of cancer risk in selected populations

  2. Conjugal Pairing in Escherichia Coli

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 8. Conjugal Pairing in Escherichia Coli. Joshua Lederberg. Classics Volume 13 Issue 8 August 2008 pp 793-794. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/013/08/0793-0794 ...

  3. Persistence Mechanisms of Conjugative Plasmids

    DEFF Research Database (Denmark)

    Bahl, Martin Iain; Hansen, Lars H.; Sørensen, Søren Johannes

    2009-01-01

    Are plasmids selfish parasitic DNA molecules or an integrated part of the bacterial genome? This chapter reviews the current understanding of the persistence mechanisms of conjugative plasmids harbored by bacterial cells and populations. The diversity and intricacy of mechanisms affecting the suc...

  4. Orderings for conjugate gradient preconditionings

    Science.gov (United States)

    Ortega, James M.

    1991-01-01

    The effect of orderings on the rate of convergence of the conjugate gradient method with SSOR or incomplete Cholesky preconditioning is examined. Some results also are presented that help to explain why red/black ordering gives an inferior rate of convergence.

  5. Magnetic field control of fluorescent polymer nanorods

    International Nuclear Information System (INIS)

    Kim, Taehyung; He, Le; Bardeen, Christopher J; Morales, Jason R; Beyermann, W P

    2011-01-01

    Nanoscale objects that combine high luminescence output with a magnetic response may be useful for probing local environments or manipulating objects on small scales. Ideally, these two properties would not interfere with each other. In this paper, we show that a fluorescent polymer host material can be doped with high concentrations of 20–30 nm diameter magnetic γ-Fe 2 O 3 particles and then formed into 200 nm diameter nanorods using porous anodic alumina oxide templates. Two different polymer hosts are used: the conjugated polymer polydioctylfluorene and also polystyrene doped with the fluorescent dye Lumogen Red. Fluorescence decay measurements show that 14% by weight loading of the γ-Fe 2 O 3 nanoparticles quenches the fluorescence of the polydioctylfluorene by approximately 33%, but the polystyrene/Lumogen Red fluorescence is almost unaffected. The three-dimensional orientation of both types of nanorods can be precisely controlled by the application of a moderate strength (∼0.1 T) external field with sub-second response times. Transmission electron microscope images reveal that the nanoparticles cluster in the polymer matrix, and these clusters may serve both to prevent fluorescence quenching and to generate the magnetic moment that rotates in response to the applied magnetic field.

  6. Bacteriophytochromes control conjugation in Agrobacterium fabrum.

    Science.gov (United States)

    Bai, Yingnan; Rottwinkel, Gregor; Feng, Juan; Liu, Yiyao; Lamparter, Tilman

    2016-08-01

    Bacterial conjugation, the transfer of single stranded plasmid DNA from donor to recipient cell, is mediated through the type IV secretion system. We performed conjugation assays using a transmissible artificial plasmid as reporter. With this assay, conjugation in Agrobacterium fabrum was modulated by the phytochromes Agp1 and Agp2, photoreceptors that are most sensitive in the red region of visible light. In conjugation studies with wild-type donor cells carrying a pBIN-GUSINT plasmid as reporter that lacked the Ti (tumor inducing) plasmid, no conjugation was observed. When either agp1(-) or agp2(-) knockout donor strains were used, plasmid DNA was delivered to the recipient, indicating that both phytochromes suppress conjugation in the wild type donor. In the recipient strains, the loss of Agp1 or Agp2 led to diminished conjugation. When wild type cells with Ti plasmid and pBIN-GUS reporter plasmid were used as donor, a high rate of conjugation was observed. The DNA transfer was down regulated by red or far-red light by a factor of 3.5. With agp1(-) or agp2(-) knockout donor cells, conjugation in the dark was about 10 times lower than with the wild type donor, and with the double knockout donor no conjugation was observed. These results imply that the phytochrome system has evolved to inhibit conjugation in the light. The decrease of conjugation under different temperature correlated with the decrease of phytochrome autophosphorylation. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. REVIEW ARTICLE Conjugated Hyperbilirubinaemia in Early Infancy ...

    African Journals Online (AJOL)

    REVIEW ARTICLE Conjugated Hyperbilirubinaemia in Early Infancy. AOK Johnson. Abstract. Conjugated hyperbilirubinaemia exists when the conjugated serum bilirubin level is more than 2 mg/dl or more than 20 per cent of the total serum bilirubin. It is always pathological in early infancy. The causes are many and diverse ...

  8. Human hair follicle benzo(a)pyrene and benzo(a)pyrene 7, 8-diol metabolism: effect of exposure to a coal tar-containing shampoo

    Energy Technology Data Exchange (ETDEWEB)

    Merk, H.F.; Mukhtar, H.; Kaufmann, I.; Das, M.; Bickers, D.R.

    1987-01-01

    Hair follicles are a readily available source of human epithelial tissue and offer an excellent system with which to study carcinogen metabolism in human populations. In this study hair follicles were employed to measure the metabolism of benzo(a)pyrene (BP), benzo(a)pyrene - 7,8-diol (BP 7,8-diol) and the enzyme mediated binding of /sup 3/H-BP to DNA. The effect of human exposure to a crude coal tar (CCT) - containing shampoo, a preparation rich in polycyclic aromatic hydrocarbons (PAHs on these parameters was also evaluated. It was found that aryl hydrocarbon hydroxylase (AHH) activity increased after use of the shampoo and enhancement of enzyme-mediated binding of BP to DNA was detected in most subjects. Hair follicles were shown to convert BP to several metabolic species and BP, 7,8-diol was also metabolised. Clotrimazole, a known inhibitor of the metabolism of BP was found to inhibit AHH and the metabolism of BP and BP 7,8-diol in human hair follicles, as were other imidazole compounds. The studies show that hair follicles represent an accessible tissue suitable for assessing the extent of PAH carcinogen metabolism in human subjects. Furthermore enzyme activity critical to cancer induction by PAHs was shown to be inducible following the use of a CCT-containing shampoo. Imidazole compounds were shown to be possible effective anti-carcinogens in human populations. 29 refs.

  9. Purification of SUMO conjugating enzymes and kinetic analysis of substrate conjugation

    Science.gov (United States)

    Yunus, Ali A.; Lima, Christopher D.

    2009-01-01

    SUMO conjugation to protein substrates requires the concerted action of a dedicated E2 ubiquitin conjugation enzyme (Ubc9) and associated E3 ligases. Although Ubc9 can directly recognize and modify substrate lysine residues that occur within a consensus site for SUMO modification, E3 ligases can redirect specificity and enhance conjugation rates during SUMO conjugation in vitro and in vivo. In this chapter, we will describe methods utilized to purify SUMO conjugating enzymes and model substrates which can be used for analysis of SUMO conjugation in vitro. We will also describe methods to extract kinetic parameters during E3-dependent or E3-independent substrate conjugation. PMID:19107417

  10. Ultraviolet Radiation Increases the Toxicity of Pyrene, 1-Aminopyrene and 1-Hydroxypyrene to Human Keratinocytes

    Directory of Open Access Journals (Sweden)

    Huey-Min Hwang

    2005-04-01

    Full Text Available Over the past several years, a great deal of interest has been focused on the harmful effects of ultraviolet (UV radiation to human skin. UV light has been implicated in aging, sunburn and skin cancer. Few studies, however, have been done to determine the effects that UV light, in conjunction with other environmental contaminants, may have on human skin. Polycyclic Aromatic Hydrocarbons (PAHs are a class of compounds that have been reported to be toxic, mutagenic and carcinogenic to many eukaryotic organisms. UV light is also known to increase the toxicity of PAHs through photo-activation and photo-modification. The purpose of this study was to assess the effects of UV-A irradiated pyrene (Pyr, 1-aminopyrene (1-AP and 1-hydroxypyrene (1-HP on human keratinocytes, the skin primary site of UV irradiated PAH exposure. Our findings indicate that simultaneous treatment of human keratinocyte cell line, HaCaT, with 1.0μg/ml pyrene, 1-AP or 1-HP and 3.9 J/cm2/min UV-A light resulted in significant inhibition of cell proliferation. Approximately 100% of the cells died in the case of UV-A irradiated 1-AP and 1-HP. In the case of UV-A irradiated pyrene, more than 70% of the cells died, indicating that UV-A is able to transform these PAHs into more harmful intermediates.

  11. Circularly Polarized Luminescence from a Pyrene-Cyclodextrin Supra-Dendron.

    Science.gov (United States)

    Zhang, Yuening; Yang, Dong; Han, Jianlei; Zhou, Jin; Jin, Qingxian; Liu, Minghua; Duan, Pengfei

    2018-05-22

    Soft nanomaterials with circularly polarized luminescence (CPL) have been currently attracting great interest. Here, we report a pyrene-containing π-peptide dendron hydrogel, which shows 1D and 2D nanostructures with varied CPL activities. It was found that the individual dendrons formed hydrogels in a wide pH range (3-12) and self-assembled into helices with pH-tuned pitches. Through chirality transfer, the pyrene unit could show CPL originated from both the monomer and excimer bands. When cyclodextrin was introduced, different supra-dendrons were obtained with β-cyclodextrin (PGAc@β-CD) and γ-cyclodextrin (PGAc@γ-CD) through host-guest interactions, respectively. Interestingly, the PGAc@β-CD and PGAc@γ-CD supra-dendrons self-assembled into 2D nanosheet and entangled nanofibers, respectively, showing cyclodextrin induced circularly polarized emission from both the monomer and excimer bands of the pyrene moiety. Thus, through a simple host-guest interaction, both the nanostructures and the chiroptical activities could be modulated.

  12. Functionalization of Fatty Acid Vesicles through Newly Synthesized Bolaamphiphile-DNA Conjugates

    DEFF Research Database (Denmark)

    Wamberg, M. C.; Wieczorek, R.; Brier, S. B.

    2014-01-01

    The surface functionalization of fatty acid vesicles will allow their use as nanoreactors for complex chemistry. In this report, the tethering of several DNA conjugates to decanoic acid vesicles for molecular recognition and synthetic purposes was explored. Due to the highly dynamic nature......), and consists of a single hydrocarbon chain of 20 carbons having on one end a triazole group linked to the S'-phosphate of the nucleic acid and on the other side a hydroxyl-group. Its insertion was so effective that a fluorescent label on the DNA complementary to the conjugate could be used to visualize fatty...... acid structures....

  13. Nano-assembly of nanodiamonds by conjugation to actin filaments.

    Science.gov (United States)

    Bradac, Carlo; Say, Jana M; Rastogi, Ishan D; Cordina, Nicole M; Volz, Thomas; Brown, Louise J

    2016-03-01

    Fluorescent nanodiamonds (NDs) are remarkable objects. They possess unique mechanical and optical properties combined with high surface areas and controllable surface reactivity. They are non-toxic and hence suited for use in biological environments. NDs are also readily available and commercially inexpensive. Here, the exceptional capability of controlling and tailoring their surface chemistry is demonstrated. Small, bright diamond nanocrystals (size ˜30 nm) are conjugated to protein filaments of actin (length ˜3-7 µm). The conjugation to actin filaments is extremely selective and highly target-specific. These unique features, together with the relative simplicity of the conjugation-targeting method, make functionalised nanodiamonds a powerful and versatile platform in biomedicine and quantum nanotechnologies. Applications ranging from using NDs as superior biological markers to, potentially, developing novel bottom-up approaches for the fabrication of hybrid quantum devices that would bridge across the bio/solid-state interface are presented and discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Co-effects of pyrene and nitrate on the activity and abundance of soil denitrifiers under anaerobic condition.

    Science.gov (United States)

    Zhou, Zhi-Feng; Yao, Yan-Hong; Wang, Ming-Xia; Zuo, Xiao-Hu

    2017-10-01

    It has previously been confirmed that polycyclic aromatic hydrocarbons (PAHs) could be degraded by soil microbes coupling with denitrification, but the relationships among soil denitrifiers, PAHs, and nitrate under obligate anaerobic condition are still unclear. Here, co-effects of pyrene and nitrate on the activity and abundance of soil denitrifiers were investigated through a 45-day incubation experiment. Two groups of soil treatments with (N 30 ) and without (N 0 ) nitrate (30 mg kg -1 dry soil) amendment were conducted, and each group contained three treatments with different pyrene concentrations (0, 30, and 60 mg kg -1 dry soil denoted as P 0 , P 30 , and P 60 , respectively). The pyrene content, abundances of denitrification concerning genes (narG, periplasmic nitrate reductase gene; nirS, cd 1 -nitrite reductase gene; nirK, copper-containing nitrite reductase gene), and productions of N 2 O and CO 2 were measured at day 3, 14, 28, and 45, and the bacterial community structures in four represented treatments (N 0 P 0 , N 0 P 60 , N 30 P 0 , and N 30 P 60 ) were analyzed at day 45. The results indicated that the treatments with higher pyrene concentration had higher final pyrene removal rates than the treatments with lower pyrene concentration. Additionally, intensive emission of N 2 O was detected in all treatments only at day 3, but a continuous production of CO 2 was measured in each treatment during the incubation. Nitrate amendment could enhance the activity of soil denitrifiers, and be helpful for soil microbes to sustain their activity. While pyrene seemed had no influence on the productions of N 2 O and CO 2 , and amendment with pyrene or nitrate both had no obvious effect on abundances of denitrification concerning genes. Furthermore, it was nitrate but not pyrene had an obvious influence on the community structure of soil bacteria. These results revealed that, under anaerobic condition, the activity and abundance of soil denitrifiers both were

  15. Fluorescence-Guided Probes of Aptamer-Targeted Gold Nanoparticles with Computed Tomography Imaging Accesses for in Vivo Tumor Resection.

    Science.gov (United States)

    Li, Cheng-Hung; Kuo, Tsung-Rong; Su, Hsin-Jan; Lai, Wei-Yun; Yang, Pan-Chyr; Chen, Jinn-Shiun; Wang, Di-Yan; Wu, Yi-Chun; Chen, Chia-Chun

    2015-10-28

    Recent development of molecular imaging probes for fluorescence-guided surgery has shown great progresses for determining tumor margin to execute the tissue resection. Here we synthesize the fluorescent gold nanoparticles conjugated with diatrizoic acid and nucleolin-targeted AS1411 aptamer. The nanoparticle conjugates exhibit high water-solubility, good biocompatibility, visible fluorescence and strong X-ray attenuation for computed tomography (CT) contrast enhancement. The fluorescent nanoparticle conjugates are applied as a molecular contrast agent to reveal the tumor location in CL1-5 tumor-bearing mice by CT imaging. Furthermore, the orange-red fluorescence emitting from the conjugates in the CL1-5 tumor can be easily visualized by the naked eyes. After the resection, the IVIS measurements show that the fluorescence signal of the nanoparticle conjugates in the tumor is greatly enhanced in comparison to that in the controlled experiment. Our work has shown potential application of functionalized nanoparticles as a dual-function imaging agent in clinical fluorescence-guided surgery.

  16. Evaluation of homologous, heterologous, and affinity conjugates for the serodiagnosis of Toxoplasma gondii and Neospora caninum in maned wolves (Chrysocyon brachyurus).

    Science.gov (United States)

    Silva, D A O; Vitaliano, S N; Mineo, T W P; Ferreira, R A; Bevilacqua, E; Mineo, J R

    2005-10-01

    Use of serological tests in the diagnosis of infectious diseases in wild animals has several limitations, primarily the difficulty of obtaining species-specific reagents. Wild canids, such as maned wolves (Chrysocyon brachyurus), are highly predisposed to infection by Toxoplasma gondii and, to a lesser extent, to Neospora caninum. The aim of the present study was to evaluate homologous, heterologous, and affinity conjugates in enzyme-linked immunosorbent assays (ELISAs) and indirect fluorescent antibody tests (IFATs) for detecting immunoglobulin (Ig) G antibodies against T. gondii and N. caninum in maned wolves. Serum samples were obtained from 59 captive animals in Brazil and tested by ELISA for T. gondii serology and IFAT for N. caninum serology using 3 different enzymatic and fluorescent conjugates: homologous (guinea pig anti-maned wolf IgG-peroxidase and -fluorescein isothiocyanate [FITC]), heterologous (rabbit anti-dog IgG-peroxidase and -FITC), and affinity (protein A-peroxidase and -FITC). Seropositivity to T. gondii was comparable among the homologous (69.5%), heterologous (74.6%), and affinity (71.2%) enzymatic conjugates. A significant positive correlation was found between the antibody levels determined by the 3 enzymatic conjugates. The highest mean antibody levels (ELISA index = 4.5) were observed with the protein A-peroxidase conjugate. The same seropositivity to N. caninum (8.5%) was found with the homologous and heterologous fluorescent conjugates, but protein A-FITC was not able to detect or confirm any positive samples with homologous or heterologous conjugates. Our results demonstrate that homologous, heterologous, and affinity conjugates might be used in ELISA for serological assays of T. gondii in wild canids, whereas for N. caninum infection, only the homologous or heterologous fluorescent conjugates have been shown to be useful.

  17. Nucleoside adducts from the in vitro reaction of benzo[a]pyrene-7,8-dihydrodiol 9,10-oxide or benzo[a]pyrene 4,5-oxide with nucleic acids.

    Science.gov (United States)

    Jennette, K W; Jeffrey, A M; Blobstein, S H; Beland, F A; Harvey, R G; Weinstein, I B

    1977-03-08

    The covalent binding of benzo[a]pyrene 4,5-oxide and benzo[a]pyrene-7,8-dihydrodiol 9,10-oxide isomer I and isomer II to nucleic acids in aqueous acetone solution has been investigated. Benzo[a]pyrene 4,5-oxide reacted preferentially with guanosine residues. On the other hand, benzo[a]pyrene-7,8-dihydrodiol 9,10-oxide isomer I and II reacted extensively with guanosine, adenosine, and cytidine residues. Time course studies showed that the reactivity of isomer I or isomer II with homopolyribonucleotides followed the order poly(G) greater than poly(A) greater than poly(C). Alkaline or enzymatic hydrolysis of the modified nucleic acids and subsequent chromatography on Sephadex LH-20 columns yielded benzo[a]pyrene-nucleotide adducts. These were enzymatically converted to the corresponding nucleosides which were resolved into several distinct components by high-pressure liquid chromatography. Evidence was obtained for the presence of multiple nucleoside adducts of guanosine, adenosine, cytidine, deoxyguanosine, deoxyadenosine, and deoxycytidine. The HPLC profiles of adducts formed with isomer I were different from the corresponding profiles of adducts formed with isomer II. Structural aspects of these nucleoside adducts are discussed.

  18. Fluorescence behavior and singlet oxygen generating abilities of aluminum phthalocyanine in the presence of anisotropic gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Mthethwa, Thandekile; Nyokong, Tebello, E-mail: t.nyokong@ru.ac.za

    2015-01-15

    Gold nanoparticles (spheres, rods and bipyramids) were synthesized. The nanocrystals were characterized by UV–visible spectrometry, transmission electron microscopy (TEM) and X-ray diffractometry (XRD). The as prepared gold nanoparticles were then conjugated to a quaternized 2,(3)-tetra [2-(dimethylamino) ethanethio] substituted Al(OH) phthalocyanine (complex 1). The conjugation of phthalocyanines with gold nanoparticles resulted in a decrease in the fluorescence quantum yields and lifetimes. Conversely, an increase in the singlet oxygen quantum yields was observed for the conjugated complex 1 in the presence of AuNPs. - Highlights: • Gold nanoparticles (spheres, rods and bipyramids) were synthesized. • Gold nanoparticles were then conjugated to a quaternized ClAl phthalocyanine. • Conjugation of phthalocyanines with gold nanoparticles resulted in a decrease in the fluorescence quantum yields. • An increase in the singlet oxygen quantum yields was observed for the phthalocyanine in the presence of nanoparticles.

  19. Formation of quinones by one-electron oxidation in the metabolism of benzo[a]pyrene and 6-fluorobenzo[a]pyrene

    International Nuclear Information System (INIS)

    Cavalieri, E.; Wong, A.; Cremonesi, P.; Warner, C.; Rogan, E.

    1986-01-01

    Metabolic activation of polycyclic aromatic hydrocarbons (PAH), as well as other chemical carcinogens, occurs by two major pathways: One-electron oxidation and two-electron oxidation, or monooxygenation. One-electron oxidation generates radical cations or radicals, depending on the molecule in which the oxidation occurs, whereas two-electron oxidation produces oxygenated metabolites. Radical cations of PAH are ultimate electrophilic metabolites capable of binding to cellular macromolecules to initiate the tumor process. In this paper the authors will provide evidence that one-electron oxidation is involved not only in PAH carcinogenesis, but also in the formation of certain metabolites. Metabolism of benzo[a]pyrene (BP) by cytochrome P-450 monooxygenase yields three classes of products: phenols, dihydrodiols and the quinones, 1,6-, 3,6- and 6,12- dione

  20. Conditions for effective removal of pyrene from an artificially contaminated soil using Pseudomonas aeruginosa 57SJ rhamnolipids

    Energy Technology Data Exchange (ETDEWEB)

    Bordas, Francois [Institut national de la recherche scientifique, Centre INRS-Eau-Terre-Environnement, Universite du Quebec, 2800 rue Einstein, C.P. 7500, Sainte-Foy, Quebec, G1V 4C7 (Canada)]. E-mail: francois.bordas@unilim.fr; Lafrance, Pierre [Institut national de la recherche scientifique, Centre Eau, Terre et Environnement, Universite du Quebec, 490, rue de la Couronne, Quebec, G1K 9A9 (Canada)]. E-mail: pierre_lafrance@inrs-ete.uquebec.ca; Villemur, Richard [Institut national de la recherche scientifique, Centre INRS-Institut Armand Frappier, Universite du Quebec, 531 bd des Prairies, Laval, Quebec, H7V 1B7 (Canada)]. E-mail: richard.villemur@inrs-iaf.uquebec.ca

    2005-11-15

    The efficacy of a new rhamnolipid biosurfactants mixture to enhance the removal of pyrene from a soil artificially contaminated was investigated. The molar solubilization ratio (MSR) and the partition coefficient between the micelles and water (log K {sub m}) were found to be 7.5 x 10{sup -3} and 5.7, respectively. From soil column studies, the pyrene removal increased linearly with the concentration of the injected biosurfactants solution above the effective critical micellar concentration (0.4 g L{sup -1}). Flushing with a 5.0 g L{sup -1} biosurfactants solution increased the pyrene concentration in the effluent by 178 times. At high biosurfactants' concentrations (2.5 and 5.0 g L{sup -1}), the cumulative pyrene recovery reached 70%. This pyrene remobilization takes place independently of the soil organic carbon solubilization. This study provides a combination of batch and column experiments in order to find the conditions for effective soil remediation using a new rhamnolipids mixture. - The potential of newly isolated biosurfactants to mobilize PAHs from contaminated soils was evaluated from the determination in dynamic conditions of their effective critical micellar concentration.

  1. Conditions for effective removal of pyrene from an artificially contaminated soil using Pseudomonas aeruginosa 57SJ rhamnolipids

    International Nuclear Information System (INIS)

    Bordas, Francois; Lafrance, Pierre; Villemur, Richard

    2005-01-01

    The efficacy of a new rhamnolipid biosurfactants mixture to enhance the removal of pyrene from a soil artificially contaminated was investigated. The molar solubilization ratio (MSR) and the partition coefficient between the micelles and water (log K m ) were found to be 7.5 x 10 -3 and 5.7, respectively. From soil column studies, the pyrene removal increased linearly with the concentration of the injected biosurfactants solution above the effective critical micellar concentration (0.4 g L -1 ). Flushing with a 5.0 g L -1 biosurfactants solution increased the pyrene concentration in the effluent by 178 times. At high biosurfactants' concentrations (2.5 and 5.0 g L -1 ), the cumulative pyrene recovery reached 70%. This pyrene remobilization takes place independently of the soil organic carbon solubilization. This study provides a combination of batch and column experiments in order to find the conditions for effective soil remediation using a new rhamnolipids mixture. - The potential of newly isolated biosurfactants to mobilize PAHs from contaminated soils was evaluated from the determination in dynamic conditions of their effective critical micellar concentration

  2. A Novel Combination of Surfactant Addition and Persulfate-assisted Electrokinetic Oxidation for Remediation of Pyrene-Contaminated Soil

    Directory of Open Access Journals (Sweden)

    M. Abtahi

    2018-03-01

    Full Text Available Effect of surfactant addition on persulfate-assisted electrokinetic remediation of pyrene-spiked soil was studied. The influence of effective factors including voltage, surfactant addition, moisture content, and persulfate concentration on the removal of initial pyrene concentration of 200 mg kg–1 were investigated. A complete pyrene removal was observed for voltage of 1 V cm–1, saturated conditions, Tween 80 concentration of 20 mL kg–1, and persulfate concentration of 100 mg kg–1 after 24 h, corresponding to pyrene mineralization of 61 %, based on TPH analysis. The experimental results were best fitted with pseudo-first-order kinetic model with correlation coefficient of 0.968 and rate constant of 0.191 min−1. The main intermediates of pyrene degradation were benzene o-toluic acid, acetic, azulene, naphthalene and decanoic acid. Finally, an unwashed hydrocarbon-contaminated soil was subjected to persulfate-assisted electrokinetic remediation, and a TPH removal of 38 % was observed for the initial TPH content of 912 mg kg–1, under the selected conditions.

  3. Incorporating functionalized polyethylene glycol lipids into reprecipitated conjugated polymer nanoparticles for bioconjugation and targeted labeling of cells

    Science.gov (United States)

    Kandel, Prakash K.; Fernando, Lawrence P.; Ackroyd, P. Christine; Christensen, Kenneth A.

    2011-03-01

    We report a simple and rapid method to prepare extremely bright, functionalized, stable, and biocompatible conjugated polymer nanoparticles incorporating functionalized polyethylene glycol (PEG) lipids by reprecipitation. These nanoparticles retain the fundamental spectroscopic properties of conjugated polymer nanoparticles prepared without PEG lipid, but demonstrate greater hydrophilicity and quantum yield compared to unmodified conjugated polymer nanoparticles. The sizes of these nanoparticles, as determined by TEM, were 21-26 nm. Notably, these nanoparticles were prepared with several PEG lipid functional end groups, including biotin and carboxy moieties that can be easily conjugated to biomolecules. We have demonstrated the availability of these end groups for functionalization using the interaction of biotin PEG lipid conjugated polymer nanoparticles with streptavidin. Biotinylated PEG lipid conjugated polymer nanoparticles bound streptavidin-linked magnetic beads, while carboxy and methoxy PEG lipid modified nanoparticles did not. Similarly, biotinylated PEG lipid conjugated polymer nanoparticles bound streptavidin-coated glass slides and could be visualized as diffraction-limited spots, while nanoparticles without PEG lipid or with non-biotin PEG lipid end groups were not bound. To demonstrate that nanoparticle functionalization could be used for targeted labelling of specific cellular proteins, biotinylated PEG lipid conjugated polymer nanoparticles were bound to biotinylated anti-CD16/32 antibodies on J774A.1 cell surface receptors, using streptavidin as a linker. This work represents the first demonstration of targeted delivery of conjugated polymer nanoparticles and demonstrates the utility of these new nanoparticles for fluorescence based imaging and sensing.We report a simple and rapid method to prepare extremely bright, functionalized, stable, and biocompatible conjugated polymer nanoparticles incorporating functionalized polyethylene glycol (PEG

  4. Photoinduced electron transfer in a Watson-Crick base-paired, 2-aminopurine:uracil-C60 hydrogen bonding conjugate.

    Science.gov (United States)

    D'Souza, Francis; Gadde, Suresh; Islam, D-M Shafiqul; Pang, Siew-Cheng; Schumacher, Amy Lea; Zandler, Melvin E; Horie, Rumiko; Araki, Yasuyaki; Ito, Osamu

    2007-02-07

    A fluorescent reporter molecule, 2-aminopurine was self-assembled via Watson-Crick base-pairing to a uracil appended fullerene to form a donor-acceptor conjugate; efficient photoinduced charge separation was confirmed by time-resolved emission and transient absorption spectral studies.

  5. Controlling photophysical properties of ultrasmall conjugated polymer nanoparticles through polymer chain packing

    KAUST Repository

    Piwonski, Hubert Marek

    2017-05-16

    Applications of conjugated polymer nanoparticles (Pdots) for imaging and sensing depend on their size, fluorescence brightness and intraparticle energy transfer. The molecular design of conjugated polymers (CPs) has been the main focus of the development of Pdots. Here we demonstrate that proper control of the physical interactions between the chains is as critical as the molecular design. The unique design of twisted CPs and fine-tuning of the reprecipitation conditions allow us to fabricate ultrasmall (3.0–4.5 nm) Pdots with excellent photostability. Extensive photophysical and structural characterization reveals the essential role played by the packing of the polymer chains in the particles in the intraparticle spatial alignment of the emitting sites, which regulate the fluorescence brightness and the intraparticle energy migration efficiency. Our findings enhance understanding of the relationship between chain interactions and the photophysical properties of CP nanomaterials, providing a framework for designing and fabricating functional Pdots for imaging applications.

  6. Multi-step intramolecular excitation energy transfer in dendritic pyrene-phosphorus(V)porphyrin heptads

    International Nuclear Information System (INIS)

    Hirakawa, Kazutaka; Segawa, Hiroshi

    2016-01-01

    Dendritic heptad molecules in which four pyrenyl groups are connected at the central phosphorus atom of the edge-porphyrins of the center-to-edge type porphyrin trimers were synthesized to investigate a multi-step excitation energy transfer. As the central energy acceptor, two types porphyrins which one was phosphorus(V)tetraphenylporphyrin (H2) and another was its derivative substituted by butoxy groups at four para-position of meso-phenyl groups (H1) were used. In the photoexcited state of the pyrene units, the excitation energy transfer to the central-porphyrin unit was observed in toluene. The excitation energy transfer is considered to be through two pathways; one is a stepwise pathway through the edge-porphyrin unit and another is a direct excitation energy transfer to the central porphyrin. The direct excitation energy transfer from pyrenes to the edge-porphyrin and central-porphyrin were observed in the case for H1. From the excited state of the edge-porphyrins, the excitation energy transfer to the central-porphyrin occurs in the H1 case. In the H2 case, the excitation energy of central-porphyrin is higher than that of H1, and the electron transfer from edge-porphyrin to the central-porphyrin become predominant process. - Highlights: • Dendritic pyrene-porphyrin heptads were synthesized. • Excitation energy transfer occurs from the pyrenyl moiety to the phosphorus(V)porphyrin. • The stepwise and direct energy transfer pathways were observed. • The quantum yields of these energy transfer pathways could be determined.

  7. Multi-step intramolecular excitation energy transfer in dendritic pyrene-phosphorus(V)porphyrin heptads

    Energy Technology Data Exchange (ETDEWEB)

    Hirakawa, Kazutaka, E-mail: hirakawa.kazutaka@shizuoka.ac.jp [Applied Chemistry and Biochemical Engineering Course, Department of Engineering, Graduate School of Integrated Science and Technology, Shizuoka University, Johoku 3-5-1, Naka-ku, Hamamatsu, Shizuoka 432-8561 (Japan); Department of Optoelectronics and Nanostructure Science, Graduate School of Science and Technology, Shizuoka University, Johoku 3-5-1, Naka-ku, Hamamatsu, Shizuoka 432-8561 (Japan); Segawa, Hiroshi [Department of Multi-Disciplinary Science - General Systems Studies, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo 153-8904 (Japan); Research Center for Advanced Science and Technology, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8904 (Japan)

    2016-11-15

    Dendritic heptad molecules in which four pyrenyl groups are connected at the central phosphorus atom of the edge-porphyrins of the center-to-edge type porphyrin trimers were synthesized to investigate a multi-step excitation energy transfer. As the central energy acceptor, two types porphyrins which one was phosphorus(V)tetraphenylporphyrin (H2) and another was its derivative substituted by butoxy groups at four para-position of meso-phenyl groups (H1) were used. In the photoexcited state of the pyrene units, the excitation energy transfer to the central-porphyrin unit was observed in toluene. The excitation energy transfer is considered to be through two pathways; one is a stepwise pathway through the edge-porphyrin unit and another is a direct excitation energy transfer to the central porphyrin. The direct excitation energy transfer from pyrenes to the edge-porphyrin and central-porphyrin were observed in the case for H1. From the excited state of the edge-porphyrins, the excitation energy transfer to the central-porphyrin occurs in the H1 case. In the H2 case, the excitation energy of central-porphyrin is higher than that of H1, and the electron transfer from edge-porphyrin to the central-porphyrin become predominant process. - Highlights: • Dendritic pyrene-porphyrin heptads were synthesized. • Excitation energy transfer occurs from the pyrenyl moiety to the phosphorus(V)porphyrin. • The stepwise and direct energy transfer pathways were observed. • The quantum yields of these energy transfer pathways could be determined.

  8. Molecular mechanics and quantum mechanical modeling of hexane soot structure and interactions with pyrene

    Directory of Open Access Journals (Sweden)

    Kubicki JD

    2000-09-01

    Full Text Available Molecular simulations (energy minimizations and molecular dynamics of an n-hexane soot model developed by Smith and co-workers (M. S. Akhter, A. R. Chughtai and D. M. Smith, Appl. Spectrosc., 1985, 39, 143; ref. 1 were performed. The MM+ (N. L. Allinger, J. Am. Chem. Soc., 1977, 395, 157; ref. 2 and COMPASS (H. Sun, J. Phys. Chem., 1998, 102, 7338; ref. 3 force fields were tested for their ability to produce realistic soot nanoparticle structure. The interaction of pyrene with the model soot was simulated. Quantum mechanical calculations on smaller soot fragments were carried out. Starting from an initial 2D structure, energy minimizations are not able to produce the observed layering within soot with either force field. Results of molecular dynamics simulations indicate that the COMPASS force field does a reasonably accurate job of reproducing observations of soot structure. Increasing the system size from a 683 to a 2732 atom soot model does not have a significant effect on predicted structures. Neither does the addition of water molecules surrounding the soot model. Pyrene fits within the soot structure without disrupting the interlayer spacing. Polycyclic aromatic hydrocarbons (PAH, such as pyrene, may strongly partition into soot and have slow desorption kinetics because the PAH-soot bonding is similar to soot–soot interactions. Diffusion of PAH into soot micropores may allow the PAH to be irreversibly adsorbed and sequestered so that they partition slowly back into an aqueous phase causing dis-equilibrium between soil organic matter and porewater.

  9. Cancer risk estimation for mixtures of coal tars and benzo(a)pyrene

    International Nuclear Information System (INIS)

    Gaylor, D.W.; Culp, S.J.; Goldstein, L.S.; Beland, F.A.

    2000-01-01

    Two-year chronic bioassays were conducted by using B6C3F1 female mice fed several concentrations of two different mixtures of coal tars from manufactured gas waste sites or benzo(a)pyrene (BaP). The purpose of the study was to obtain estimates of cancer potency of coal tar mixtures, by using conventional regulatory methods, for use in manufactured gas waste site remediation. A secondary purpose was to investigate the validity of using the concentration of a single potent carcinogen, in this case benzo(a)pyrene, to estimate the relative risk for a coal tar mixture. The study has shown that BaP dominates the cancer risk when its concentration is greater than 6,300 ppm in the coal tar mixture. In this case the most sensitive tissue site is the forestomach. Using low-dose linear extrapolation, the lifetime cancer risk for humans is estimated to be: Risk -4 (ppm coal tar in total diet) + 240 x 10 -4 (ppm BaP in total diet), based on forestomach tumors. If the BaP concentration in the coal tar mixture is less than 6,300 ppm, the more likely case, then lung tumors provide the largest estimated upper limit of risk, Risk -4 (ppm coal tar in total diet), with no contribution of BaP to lung tumors. The upper limit of the cancer potency (slope factor) for lifetime oral exposure to benzo(a)pyrene is 1.2 x 10 -3 per microg per kg body weight per day from this Good Laboratory Practice (GLP) study compared with the current value of 7.3 x 10 -3 per microg per kg body weight per day listed in the US EPA Integrated Risk Information System

  10. Quantification and imaging of HER2 protein using nanocrystals conjugated with single-domain antibodies

    International Nuclear Information System (INIS)

    Glukhov, S; Berestovoy, M; Nabiev, I; Sukhanova, A; Chames, P; Baty, D

    2017-01-01

    This study dealt with quantification and imaging of human epidermal growth factor receptor 2 (HER2), an important prognostic marker for cancer diagnosis and treatment, using specific quantum-dot-based conjugates. Fluorescent inorganic nanocrystals or quantum dots (QDs) are extremely highly resistant to photobleaching and have a high emission quantum yield and a continuous range of emission spectra, from the ultraviolet to the infrared regions. Ultrasmall nanoprobes consisting of highly affine anti-HER2 single-domain antibodies (sdAbs or 'nanobodies') conjugated with QDs in a strictly oriented manner have been designed. QDs with a fluorescence peak maxima at wavelengths of 562 nm, 569 nm, 570 nm or in the near-infrared region were used. Here, we present our results of ISA quantification of HER2 protein, in situ imaging of HER2 protein on the surface of HER2-positive SK-BR-3 cells in immunohistochemical experiments, and counting of stained with anti-HER2 conjugates HER2-positive SK-BR-3 cells in their mixture with unstained cells of the same culture in flow cytometry experiments. The data demonstrate that the anti-HER2 QD–sdAb conjugates obtained are highly specific and sensitive and could be used in numerous applications for advanced integrated diagnosis. (paper)

  11. Quantification and imaging of HER2 protein using nanocrystals conjugated with single-domain antibodies

    Science.gov (United States)

    Glukhov, S.; Berestovoy, M.; Chames, P.; Baty, D.; Nabiev, I.; Sukhanova, A.

    2017-01-01

    This study dealt with quantification and imaging of human epidermal growth factor receptor 2 (HER2), an important prognostic marker for cancer diagnosis and treatment, using specific quantum-dot-based conjugates. Fluorescent inorganic nanocrystals or quantum dots (QDs) are extremely highly resistant to photobleaching and have a high emission quantum yield and a continuous range of emission spectra, from the ultraviolet to the infrared regions. Ultrasmall nanoprobes consisting of highly affine anti-HER2 single-domain antibodies (sdAbs or "nanobodies") conjugated with QDs in a strictly oriented manner have been designed. QDs with a fluorescence peak maxima at wavelengths of 562 nm, 569 nm, 570 nm or in the near-infrared region were used. Here, we present our results of ISA quantification of HER2 protein, in situ imaging of HER2 protein on the surface of HER2-positive SK-BR-3 cells in immunohistochemical experiments, and counting of stained with anti-HER2 conjugates HER2-positive SK-BR-3 cells in their mixture with unstained cells of the same culture in flow cytometry experiments. The data demonstrate that the anti-HER2 QD-sdAb conjugates obtained are highly specific and sensitive and could be used in numerous applications for advanced integrated diagnosis.

  12. Recent development of fluorescent imaging for specific detection of tumors

    International Nuclear Information System (INIS)

    Nakata, Eiji; Morii, Takashi; Uto, Yoshihiro; Hori, Hitoshi

    2011-01-01

    Increasing recent studies on fluorescent imaging for specific detection of tumors are described here on strategies of molecular targeting, metabolic specificity and hypoxic circumstance. There is described an instance of a conjugate of antibody and pH-activable fluorescent ligand, which specifically binds to the tumor cells, is internalized in the cellular lysozomes where their pH is low, and then is activated to become fluorescent only in viable tumor cells. For the case of metabolic specificity, excessive loading of the precursor (5-aminolevulinic acid) of protoporphyrin IX (ppIX), due to their low activity to convert ppIX to heme B, results in making tumors observable in red as ppIX emits fluorescence (red, 585 nm) when excited by blue ray of 410 nm. Similarly, imaging with indocyanine green which is accumulated in hepatoma cells is reported in success in detection of small lesion and metastasis when the dye is administered during operation. Reductive reactions exceed in tumor hypoxic conditions, of which feature is usable for imaging. Conjugates of nitroimidazole and fluorescent dye are reported to successfully image tumors by nitro reduction. Authors' UTX-12 is a non-fluorescent nitroaromatic derivative of pH-sensitive fluorescent dye seminaphtharhodafluor (SNARF), and is designed for the nitro group, the hypoxia-responding sensor, to be reduced in tumor hypoxic conditions and then for the aromatic moiety to be cleaved to release free SNARF. Use of hypoxia-inducible factor-1 (HIF-1) for imaging has been also reported in many. As above, studies on fluorescent imaging for specific detection of tumors are mostly at fundamental step but its future is conceivably promising along with advances in other technology like fluorescent endoscopy and multimodal imaging. (author)

  13. Quantitative Analysis of Subcellular Distribution of the SUMO Conjugation System by Confocal Microscopy Imaging.

    Science.gov (United States)

    Mas, Abraham; Amenós, Montse; Lois, L Maria

    2016-01-01

    Different studies point to an enrichment in SUMO conjugation in the cell nucleus, although non-nuclear SUMO targets also exist. In general, the study of subcellular localization of proteins is essential for understanding their function within a cell. Fluorescence microscopy is a powerful tool for studying subcellular protein partitioning in living cells, since fluorescent proteins can be fused to proteins of interest to determine their localization. Subcellular distribution of proteins can be influenced by binding to other biomolecules and by posttranslational modifications. Sometimes these changes affect only a portion of the protein pool or have a partial effect, and a quantitative evaluation of fluorescence images is required to identify protein redistribution among subcellular compartments. In order to obtain accurate data about the relative subcellular distribution of SUMO conjugation machinery members, and to identify the molecular determinants involved in their localization, we have applied quantitative confocal microscopy imaging. In this chapter, we will describe the fluorescent protein fusions used in these experiments, and how to measure, evaluate, and compare average fluorescence intensities in cellular compartments by image-based analysis. We show the distribution of some components of the Arabidopsis SUMOylation machinery in epidermal onion cells and how they change their distribution in the presence of interacting partners or even when its activity is affected.

  14. Multimedia transport of particle-bound organics: benzo(a)pyrene test case

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, P A; Cohen, Y

    1986-01-01

    A screening multimedia-compartmental (MCM) modeling approach is presented for predicting the distribution of particle-bound pollutants within an environment consisting of the atmosphere, surface water, and surface soil compartments. An MCM model was used to simulate the dynamic distribution of Benzo(a)Pyrene (B(a)P) for a study region located in southeast Ohio. The model incorporates theoretical estimates of the dry deposition velocity and a new semi-empirical model for rain scavenging of B(a)P. The predicted concentrations of B(a)P compared favorably with available field data.

  15. Immunotoxicity effect of benzo[α]pyrene on scallop Chlamys farreri

    Science.gov (United States)

    Zhang, Lin; Pan, Luqing; Liu, Jing

    2009-03-01

    The toxic effects of benzo[ α]pyrene (B[ α]P) at different concentrations (0.1, 0.5, 1, 2.5 and 7.5 μgL-1) on scallop ( Chlamy farreri) immune system were studied. The results showed that B[ α]P had significant toxic effects on the haemocyte counts, neutral red uptake, phagocytosis, bacteriolytic and antibacterial activity ( P0.05). Thus, B[ α] has evident toxic effects on scallop immune system, which supports the view that a relationship exists between pollution and immunomodulation in aquatic organisms.

  16. Microplastic does not magnify the acute effect of PAH pyrene on predatory performance of a tropical fish (Lates calcarifer)

    DEFF Research Database (Denmark)

    Guven, Olgac; Bach, Lis; Munk, Peter

    2018-01-01

    Microplastic (MP) leads to widespread pollution in the marine ecosystem. In addition to the physical hazard posed by ingestion of microplastic particles, concern is also on their potential as vector for transport of hydrophobic contaminants. We studied experimentally the single and interactive...... effects of microplastic and pyrene, a polycyclic aromatic hydrocarbon, on the swimming behaviour and predatory performance of juvenile barramundi (Lates calcarifer). Juveniles (18+ days post hatch) were exposed to MPs, or pyrene (100nM), or combination of both and feeding rate and foraging activity...... no effect on feeding while swimming speed showed a significant decrease. Thus, our results confirm that short-time exposure to pyrene impacts performance of fish juveniles, while additional exposure to microplastic influenced their activity but not their feeding rate at the given conditions. Further studies...

  17. Life history traits and the activity of antioxidative enzymes in Lymantria dispar L. (lepidoptera, lymantriidae) larvae exposed to benzo[a]pyrene.

    Science.gov (United States)

    Ilijin, Larisa; Mrdaković, Marija; Todorović, Dajana; Vlahović, Milena; Gavrilović, Anja; Mrkonja, Aleksandra; Perić-Mataruga, Vesna

    2015-11-01

    Increased presence of benzo[a]pyrene in the environment underlines the need for development of sensitive biomarkers for monitoring. Antioxidative enzymes could be used as early-warning signals because of their sensitivity and applicability. The activity of 2 antioxidative enzymes, superoxide dismutase (SOD) and catalase (CAT), were measured in midgut tissues of fifth instar Lymantria dispar larvae exposed to different concentrations of benzo[a]pyrene: 2 ng, 10 ng, 20 ng, 100 ng, 200 ng, and 2000 ng benzo[a]pyrene/g dry food weight. Larval development, larval mass, and relative growth rate were also monitored. The authors detected prolonged larval development, as well as reduced larval mass and relative growth rate in larvae exposed to all benzo[a]pyrene concentrations. The L. dispar midgut SOD activity was significantly increased, and 2 SOD isoforms were detected on native polyacrylamide gel electrophoresis in larvae fed on artificial diet supplemented with benzo[a]pyrene. In contrast, the control group had only 1 isoform. Catalase activity was significantly increased in all benzo[a]pyrene-treated larvae. Native gel electrophoresis showed that a switch in active CAT isoforms occurred after benzo[a]pyrene treatment. Thus, SOD and CAT in polyphagous herbivorous L. dispar larvae are very sensitive to low concentrations of benzo[a]pyrene. Therefore, they could be used as biomarkers for exposure and effects of this toxic polycyclic aromatic hydrocarbon. © 2015 SETAC.

  18. LC/MSMS STUDY OF BENZO[A]PYRENE-7,8-QUINONE ADDUCTION TO GLOBIN TRYPTIC PEPTIDES AND N-ACETYLAMINO ACIDS

    Science.gov (United States)

    Benzo[a]pyrene-7,8-quinone (BPQ) is regarded as a reactive genotoxic compound enzymatically formed from a xenobiotic precursor benzo[a]pyrene-7,8-diol by aldo-keto-reductase family of enzymes. Because BPQ, a Michael electrophile, was previously shown to react with oligonucleotide...

  19. Induction of secondary metabolism by environmental pollutants: metabolization of pyrene and formation of 6,8-dihydroxy-3-methylisocoumarin by Crinipellis stipitaria JK 364

    International Nuclear Information System (INIS)

    Lange, B.; Kremer, S.; Sterner, O.; Anke, H.

    1995-01-01

    In submerged cultures, when grown in the presence of pyrene, the saprophytic and plant inhabiting basidiomycete Crinipellis stipitaria was found to produce 6,8-dihydroxy-3-methyl-isocoumarin. The amount of 6,8-dihydroxy-3-methylisocoumarin formed depended on the concentration of pyrene in the medium. In cultures incubated without pyrene or with less than 2.5 mg/l no formation of 6,8-dihydroxy-3-methylisocoumarin was observed. Besides pyrene, chrysene, anotther four ring polycyclic aromatic hydrocarbon, induced isocoumarin formation whereas anthracene, phenanthrene or fluoranthene were not effective. During metabilization experiments with [4,5,9,10- 14 C]pyrene (0.4 mCi (14.8 kBq)/mmol), labelled 6,8-dihydroxy-3-methylsiocoumarin (specific activity 15 μCi (0.6 kBq)/mmol) was identified. When C. stipitaria JK 364 was incubated for 14 days with 5 μCi (0.2 kBq) sodium [2- 14 C]acetate and 10 mg/l pyrene, labelled 6,8-dihydroxy-3-methylisocoumarin was isolated from the culture. The results are in agreement with the polyketide origin of the isocoumarin and proof the breakdown of pyrene to acetate which is a central intermediate in the pathway from pyrene to 6,8-dihydroxy-3-methylisocoumarin. (orig.)

  20. Structure Property Relationships in Organic Conjugated Systems

    OpenAIRE

    O'Neill, Luke

    2008-01-01

    A series of pi(п) conjugated oligomers containing 1 to 6 monomer units were studied by absorption and photoluminescence spectroscopies. The results are discussed and examined with regard to the variation of the optical properties with the increase of effective conjugation length. It was found that there was a linear relationship between the positioning of the absorption and photoluminescence maxima plotted against inverse conjugation length. The relationships are in good agreement with the si...

  1. Properties of acid gels made from sodium caseinate-maltodextrin conjugates prepared by a wet heating method.

    Science.gov (United States)

    Zhang, Shuwen; Gong, Yuansheng; Khanal, Som; Lu, Yanjie; Lucey, John A

    2017-11-01

    Covalent attachment of polysaccharides to proteins (conjugation) via the Maillard reaction has been extensively studied. Conjugation can lead to a significant improvement in protein functionality (e.g., solubility, emulsification, and heat stability). Caseins have previously been successfully conjugated with maltodextrin (Md), but the effect on the detailed acid gelation properties has not been examined. We studied the effect of conjugating sodium caseinate (NaCN) with 3 different sized Md samples via the Maillard reaction in aqueous solutions. The Md samples had dextrose equivalents of 4 to 7, 9 to 12, and 20 to 23 for Md40, Md100, and Md200, respectively. The conjugation reaction was performed in mixtures with 5% NaCN and 5% Md, which were heated at 90°C for 10 h. The degree of conjugation was estimated from the reduction in free amino groups as well as color changes. Sodium dodecyl sulfate-PAGE analysis was performed to confirm conjugation by employing staining of both protein and carbohydrate bands. The molar mass of samples was determined by size-exclusion chromatography coupled with multi-angle laser light scattering. After the conjugation reaction, samples were then gelled by the addition of 0.63% (wt/vol) glucono-δ-lactone at 30°C, such that samples reached pH 4.6 after about 13 h. The rheological properties of samples during acidification was monitored by small-strain dynamic oscillatory rheology. The microstructure of acid gels at pH 4.6 was examined by fluorescence microscopy. Conjugation resulted in a loss of 10.8, 8.8, and 11.9% of the available amino groups in the protein for the NaCN-Md40 conjugates (C40), NaCN-Md100 conjugates (C100), and NaCN-Md100 conjugates (C200), respectively. With a decrease in the size of the type of Md, an increase occurred in the molar mass of the resultant conjugate. The weight average molar masses of NaCN-Md samples were 340, 368, and 425 kDa for the conjugates C40, C100, and C200, respectively. Addition of Md to Na

  2. Humic acid-bonded silica as a novel sorbent for solid-phase extraction of benzo[a]pyrene in edible oils

    International Nuclear Information System (INIS)

    Luo Dan; Yu Qiongwei; Yin Hongrui; Feng Yuqi

    2007-01-01

    A novel solid-phase extraction (SPE) sorbent, humic acid-bonded silica (HAS), was prepared. Humic acids (HAs) were grafted onto silica matrices via an amide linkage between humyl chloride and the amido terminus of 3-aminopropyltrimethoxysilane (APTS)-silica gel. The resulting material was characterized by Fourier transform infrared spectrometer, elemental analysis, and nitrogen adsorption analysis. This sorbent exhibits an excellent adsorption capacity for some electron-abundant analytes owing to its peculiar structure. In this paper, we choose benzo[a]pyrene (BaP) in oil as a probe to validate the adsorption capacity of the material. Thus a fast, cheap and simple SPE method with humic acid-bonded silica cartridge for edible oil clean-up, followed by high-performance liquid chromatography (HPLC) with fluorescence detection was established. The effects of experimental variables, such as washing and elution solvents, and the amount of sorbents have been studied. The recoveries of BaP in edible oils spiked at 0.2-100 μg kg -1 were in the range of 78.8-102.7% with relative standard deviations ranging between 1.3 and 9.3%; the limit of detection was -0.06 μg kg -1

  3. Biodegradation of benzo(a)pyrene by two freshwater microalgae Selenastrum capricornutum and Scenedesmus acutus: a comparative study useful for bioremediation.

    Science.gov (United States)

    García de Llasera, Martha Patricia; Olmos-Espejel, José de Jesús; Díaz-Flores, Gabriel; Montaño-Montiel, Adriana

    2016-02-01

    A comparative evaluation of the removal of benzo(a)pyrene (BaP) by sorption and degradation by two microalgal species, Selenastrum capricornutum and Scenedesmus acutus was performed. The monitoring of the amount of BaP remaining in the liquid culture media and the biomass along with the appearance of three metabolites (4,5 dihydrodiol-BaP; 7,8-dihydrodiol-BaP; and 9,10 dihydrodiol-BaP) at short time periods (from 0.25 to 72 h) in cultures exposed to BaP was made by high-performance liquid chromatography (HPLC) with fluorescence and UV detection. Complete removal of BaP was achieved by the two live microalgal species: S. capricornutum at 15 h of exposure (99%) and S. acutus at 72 h of exposure (95%). Sorption is an important phenomenon for BaP removal by S. capricornutum but biodegradation is the principal means of removing BaP in live cells. The formation of metabolites by S. capricornutum is rapid and seems to be proportional to the amount of the BaP added to cultures. In contrast, in these bioassays, most of the BaP removal of S. acutus is due to sorption rather than degradation. The appearance of metabolites in the cultures is very slow and at a low amount compared to cultures of S. capricornutum. The similarities and differences existing between the two microalgae are important for the establishment of the conditions for bioremediation.

  4. Protocol for Evaluating the Permissiveness of Bacterial Communities Toward Conjugal Plasmids by Quantification and Isolation of Transconjugants

    DEFF Research Database (Denmark)

    Klümper, Uli; Dechesne, Arnaud; Smets, Barth F.

    2014-01-01

    may encode catabolic pathways, virulence factors, and antibiotic or metal resistances, it is of environmental, evolutionary, and medical relevance to track and monitor the fate of plasmids in mixed microbial community. When assessing the short-term and long-term implications of conjugal plasmid...... a gfp-tagged plasmid in a mCherry red fluorescently tagged donor strain repressing gfp expression. We take advantage of fluorescent marker genes to microscopically detect plasmid transfer events and use subsequent high-throughput fluorescence-activated cell sorting (FACS) to isolate...

  5. Targeted delivery of polyamidoamine-paclitaxel conjugate functionalized with anti-human epidermal growth factor receptor 2 trastuzumab

    Directory of Open Access Journals (Sweden)

    Ma P

    2015-03-01

    Full Text Available Pengkai Ma,1 Xuemei Zhang,1 Ling Ni,2 Jinming Li,2 Fengpu Zhang,1 Zheng Wang,1 Shengnan Lian,1 Kaoxiang Sun1 1School of Pharmacy, Yantai University, Yantai, Shandong Province, People’s Republic of China; 2State Key Laboratory of Long-acting and Targeting Drug Delivery System, Yantai, Shandong Province, People’s Republic of China Background: Antibody-dendrimer conjugates have the potential to improve the targeting and release of chemotherapeutic drugs at the tumor site while reducing adverse side effects caused by drug accumulation in healthy tissues. In this study, trastuzumab (TMAB, which binds to human epidermal growth factor receptor 2 (HER2, was used as a targeting agent in a TMAB-polyamidoamine (PAMAM conjugate carrying paclitaxel (PTX specifically to cells overexpressing HER2. Methods: TMAB was covalently linked to a PAMAM dendrimer via bifunctional polyethylene glycol (PEG. PTX was conjugated to PAMAM using succinic anhydride as a cross-linker, yielding TMAB-PEG-PAMAM-PTX. Dynamic light scattering and transmission electron microscopy were used to characterize the conjugates. The cellular uptake and in vivo biodistribution were studied by fluorescence microscopy, flow cytometry, and Carestream In Vivo FX, respectively. Results: Nuclear magnetic resonance spectroscopy demonstrated that PEG, PTX, fluorescein isothiocyanate, and cyanine7 were conjugated to PAMAM. Ultraviolet-visible spectroscopy and sodium dodecyl sulfate polyacrylamide gel electrophoresis demonstrated that TMAB was conjugated to PEG-PAMAM. Dynamic light scattering and transmission electron microscopy measurements revealed that the different conjugates ranged in size between 10 and 35 nm and had a spherical shape. In vitro cellular uptake demonstrated that the TMAB-conjugated PAMAM was taken up by HER2-overexpressing BT474 cells more efficiently than MCF-7 cells that expressed lower levels of HER2. Co-localization experiments indicated that TMAB-conjugated PAMAM was

  6. Conjugated Polymers for Energy Production

    DEFF Research Database (Denmark)

    Livi, Francesco

    This dissertation is aimed at developing materials for flexible, large area, ITO-free polymer solar cells (PSCs) fully printed under ambient conditions. A large screening of conjugated polymers, both novel and well-known materials, has been carried out in order to find suitable candidates...... polymerization method for industrial production of polymers. Several DArP protocols have been employed for the synthesis of PPDTBT leading to polymers with high structural regularity and photovoltaic performances comparable with the same materials synthesized via Stille cross-coupling polymerization...

  7. Novel ?-cyclodextrin?eosin conjugates

    OpenAIRE

    Benkovics, G?bor; Afonso, Damien; Darcsi, Andr?s; B?ni, Szabolcs; Conoci, Sabrina; Fenyvesi, ?va; Szente, Lajos; Malanga, Milo; Sortino, Salvatore

    2017-01-01

    Eosin B (EoB) and eosin Y (EoY), two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-β-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy an...

  8. Test of charge conjugation invariance

    International Nuclear Information System (INIS)

    Nefkens, B.M.K.; Prakhov, S.; Gaardestig, A.; Clajus, M.; Marusic, A.; McDonald, S.; Phaisangittisakul, N.; Price, J.W.; Starostin, A.; Tippens, W.B.; Allgower, C.E.; Spinka, H.; Bekrenev, V.; Koulbardis, A.; Kozlenko, N.; Kruglov, S.; Lopatin, I.; Briscoe, W.J.; Shafi, A.; Comfort, J.R.

    2005-01-01

    We report on the first determination of upper limits on the branching ratio (BR) of η decay to π 0 π 0 γ and to π 0 π 0 π 0 γ. Both decay modes are strictly forbidden by charge conjugation (C) invariance. Using the Crystal Ball multiphoton detector, we obtained BR(η→π 0 π 0 γ) -4 at the 90% confidence level, in support of C invariance of isoscalar electromagnetic interactions of the light quarks. We have also measured BR(η→π 0 π 0 π 0 γ) -5 at the 90% confidence level, in support of C invariance of isovector electromagnetic interactions

  9. Does the Digestibility of Cyclodextrins Influence the In Vivo Absorption of Benzo[a] pyrene in Rats?

    DEFF Research Database (Denmark)

    Olesen, Niels Erik; Vana, Vasiliki; Holm, Rene

    2016-01-01

    -Cyclodextrin is digestible in contrast to b-cyclodextrins. This could potentially limit the sensitivity toward overdose, which was evaluated using benzo[a] pyrene in this study, in which rats were administered benzo[a] pyrene and different doses of the 2 cyclodextrins. Both cyclodextrins lowered the area under the curve......,000 at the concentration where a significant decrease in the absorption was observed. No difference was observed between the 2 cyclodextrins, so digestibility seemed less important. More interesting was that the decrease in absorption was relatively small when compared with literature values, suggesting that the effect...

  10. Homogeneous non-competitive bioaffinity assay based on fluorescence resonance energy transfer

    International Nuclear Information System (INIS)

    Kokko, Tiina; Kokko, Leena; Soukka, Tero; Loevgren, Timo

    2007-01-01

    A homogeneous non-competitive assay principle for measurement of small analytes based on quenching of fluorescence is described. Fluorescence resonance energy transfer (FRET) occurs between the donor, intrinsically fluorescent europium(III)-chelate conjugated to streptavidin, and the acceptor, quencher dye conjugated to biotin derivative when the biotin-quencher is bound to Eu-streptavidin. Fluorescence can be measured only from those streptavidins that are bound to biotin of the sample, while the fluorescence of the streptavidins that are not occupied by biotin are quenched by quencher-biotin conjugates. The quenching efficiencies of the non-fluorescent quencher dyes were over 95% and one dye molecule was able to quench the fluorescence of more than one europium(III)-chelate. This, however, together with the quadrovalent nature of streptavidin limited the measurable range of the assay to 0.2-2 nmol L -1 . In this study we demonstrated that FRET could be used to design a non-competitive homogeneous assay for a small analyte resulting in equal performance with competitive heterogeneous assay

  11. Fluorescent nanodiamonds and their use in biomedical research

    Science.gov (United States)

    Suarez-Kelly, Lorena P.; Rampersaud, Isaac V.; Moritz, Charles E.; Campbell, Amanda R.; Hu, Zhiwei; Alkahtani, Masfer H.; Alghannam, Fahad S.; Hemmer, Phillip; Carson, William E.; Rampersaud, Arfaan A.

    2016-03-01

    Nanodiamonds containing color-centers produce non-quenching fluorescence that is easily detected. This makes them useful for cellular, proteomic and genomic applications. However, fluorescent nanodiamonds have yet to become popular in the biomedical research community as labeling reagents. We discuss production of nanodiamonds with distinct color-centers and assess their biocompatibility and techniques for bioconjugation. Fluorescent diamonds were fabricated by electron irradiation of high-pressure, high-temperature micron-sized diamonds which generated diamonds with vacancy-related defects (V). These diamonds were annealed to create nitrogen vacancy (NV)-centers then following a milling step were fractionated into nanoparticle sizes of 30, 60, and 95 nm. Optical characterization of Vand NV-center diamonds demonstrated fluorescence in two distinct green and red channels, respectively. In vitro studies demonstrated that these nanodiamonds are biocompatible and readily taken up by murine macrophage cells. Quantification of NV-center nanodiamond uptake by flow cytometry, showed that uptake was independent of nanodiamond size. Confocal microscopy demonstrated that NV-center nanodiamonds accumulate within the cytoplasm of these cells. NV-center nanodiamonds were then conjugated with streptavidin using a short polyethylene chain as linker. Conjugation was confirmed via a catalytic assay employing biotinylated-horseradish peroxidase. We present a technique for large-scale production of biocompatible conjugated V- or NV-center nanodiamonds. Functional testing is essential for standardization of fluorescent nanodiamond bioconjugates and quality control. Large-scale production of bioconjugated fluorescent nanodiamonds is crucial to their development as novel tools for biological and medical applications.

  12. ⁹⁹mTc pyrene derivative complex causes double-strand breaks in dsDNA mainly through cluster-mediated indirect effect in aqueous solution.

    Directory of Open Access Journals (Sweden)

    Wei-Ju Chung

    Full Text Available Radiation therapy for cancer patients works by ionizing damage to nuclear DNA, primarily by creating double-strand breaks (DSB. A major shortcoming of traditional radiation therapy is the set of side effect associated with its long-range interaction with nearby tissues. Low-energy Auger electrons have the advantage of an extremely short effective range, minimizing damage to healthy tissue. Consequently, the isotope ⁹⁹mTc, an Auger electron source, is currently being studied for its beneficial potential in cancer treatment. We examined the dose effect of a pyrene derivative ⁹⁹mTc complex on plasmid DNA by using gel electrophoresis in both aqueous and methanol solutions. In aqueous solutions, the average yield per decay for double-strand breaks is 0.011±0.005 at low dose range, decreasing to 0.0005±0.0003 in the presence of 1 M dimethyl sulfoxide (DMSO. The apparent yield per decay for single-strand breaks (SSB is 0.04±0.02, decreasing to approximately a fifth with 1 M DMSO. In methanol, the average yield per decay of DSB is 0.54±0.06 and drops to undetectable levels in 2 M DMSO. The SSB yield per decay is 7.2±0.2, changing to 0.4±0.2 in the presence of 2 M DMSO. The 95% decrease in the yield of DSB in DMSO indicates that the main mechanism for DSB formation is through indirect effect, possibly by cooperative binding or clustering of intercalators. In the presence of non-radioactive ligands at a near saturation concentration, where radioactive Tc compounds do not form large clusters, the yield of SSB stays the same while the yield of DSB decreases to the value in DMSO. DSBs generated by ⁹⁹mTc conjugated to intercalators are primarily caused by indirect effects through clustering.

  13. ⁹⁹mTc pyrene derivative complex causes double-strand breaks in dsDNA mainly through cluster-mediated indirect effect in aqueous solution.

    Science.gov (United States)

    Chung, Wei-Ju; Cui, Yujia; Huang, Feng-Yun J; Tu, Tzu-Hui; Yang, Tzu-Sen; Lo, Jem-Mau; Chiang, Chi-Shiun; Hsu, Ian C

    2014-01-01

    Radiation therapy for cancer patients works by ionizing damage to nuclear DNA, primarily by creating double-strand breaks (DSB). A major shortcoming of traditional radiation therapy is the set of side effect associated with its long-range interaction with nearby tissues. Low-energy Auger electrons have the advantage of an extremely short effective range, minimizing damage to healthy tissue. Consequently, the isotope ⁹⁹mTc, an Auger electron source, is currently being studied for its beneficial potential in cancer treatment. We examined the dose effect of a pyrene derivative ⁹⁹mTc complex on plasmid DNA by using gel electrophoresis in both aqueous and methanol solutions. In aqueous solutions, the average yield per decay for double-strand breaks is 0.011±0.005 at low dose range, decreasing to 0.0005±0.0003 in the presence of 1 M dimethyl sulfoxide (DMSO). The apparent yield per decay for single-strand breaks (SSB) is 0.04±0.02, decreasing to approximately a fifth with 1 M DMSO. In methanol, the average yield per decay of DSB is 0.54±0.06 and drops to undetectable levels in 2 M DMSO. The SSB yield per decay is 7.2±0.2, changing to 0.4±0.2 in the presence of 2 M DMSO. The 95% decrease in the yield of DSB in DMSO indicates that the main mechanism for DSB formation is through indirect effect, possibly by cooperative binding or clustering of intercalators. In the presence of non-radioactive ligands at a near saturation concentration, where radioactive Tc compounds do not form large clusters, the yield of SSB stays the same while the yield of DSB decreases to the value in DMSO. DSBs generated by ⁹⁹mTc conjugated to intercalators are primarily caused by indirect effects through clustering.

  14. Repair of DNA damage induced by ionizing radiation and benzo[a]pyrene in mammalian cells

    International Nuclear Information System (INIS)

    Cerutti, P.; Shinohara, K.; Remsen, J.

    1977-01-01

    The biological effects of DNA-damaging agents are codetermined by the structural characteristics of the lesions, the quality and extent of the local distortion of DNA and chromatin structure, and the mode(s) of damage processing used by a given type of cell. Persistent damage (i.e., damage that is not removed before it is reached by DNA replication) may be mostly responsible for mutagenesis and carcinogenesis. To understand the effects of environmental physical and chemical DNA-damaging agents on human health, the mechanisms of damage processing used by human cells have to be elucidated. We report our studies of the excision of gamma-ray products of the 5,6-dihydroxydihydrothymine type (t 0 /sub 2//sup γ/) in normal human fibroblasts and in fibroblasts from patients with the hereditary diseases Fanconi's anemia (FA) and ataxia telangiectasia (AT). Both diseases are characterized by chromosomal instability and increased susceptibility for the development of cancer. Formation and repair of DNA-benzo[a]pyrene adducts were studied in baby hamster kidney cells, secondary mouse embryo cells, and human lymphoma. The relative persistence of DNA-B[a]P may explain the high mutagenicity of the 7,8-dihydroxy-9,10-epoxy-tetrahydrobenzo[a]pyrene metabolites in rodent cells that has been observed by several investigators

  15. Targeting Antibodies to Carbon Nanotube Field Effect Transistors by Pyrene Hydrazide Modification of Heavy Chain Carbohydrates

    Directory of Open Access Journals (Sweden)

    Steingrimur Stefansson

    2012-01-01

    Full Text Available Many carbon nanotube field-effect transistor (CNT-FET studies have used immobilized antibodies as the ligand binding moiety. However, antibodies are not optimal for CNT-FET detection due to their large size and charge. Their size can prevent ligands from reaching within the Debye length of the CNTs and a layer of charged antibodies on the circuits can drown out any ligand signal. In an attempt to minimize the antibody footprint on CNT-FETs, we examined whether pyrene hydrazide modification of antibody carbohydrates could reduce the concentration required to functionalize CNT circuits. The carbohydrates are almost exclusively on the antibody Fc region and this site-specific modification could mediate uniform antibody orientation on the CNTs. We compared the hydrazide modification of anti-E. coli O157:H7 polyclonal antibodies to pyrenebutanoic acid succinimidyl ester-coated CNTs and carbodiimide-mediated antibody CNT attachment. Our results show that the pyrene hydrazide modification was superior to those methods with respect to bacteria detection and less than 1 nM labeled antibody was required to functionalize the circuits.

  16. Pyrene synthesis in circumstellar envelopes and its role in the formation of 2D nanostructures

    Science.gov (United States)

    Zhao, Long; Kaiser, Ralf I.; Xu, Bo; Ablikim, Utuq; Ahmed, Musahid; Joshi, Dharati; Veber, Gregory; Fischer, Felix R.; Mebel, Alexander M.

    2018-05-01

    For the past decades, the hydrogen-abstraction/acetylene-addition (HACA) mechanism has been instrumental in attempting to untangle the origin of polycyclic aromatic hydrocarbons (PAHs) as identified in carbonaceous meteorites such as Allende and Murchison. However, the fundamental reaction mechanisms leading to the synthesis of PAHs beyond phenanthrene (C14H10) are still unknown. By exploring the reaction of the 4-phenanthrenyl radical (C14H9•) with acetylene (C2H2) under conditions prevalent in carbon-rich circumstellar environments, we show evidence of a facile, isomer-selective formation of pyrene (C16H10). Along with the hydrogen-abstraction/vinylacetylene-addition (HAVA) mechanism, molecular mass growth processes from pyrene may lead through systematic ring expansions not only to more complex PAHs, but ultimately to 2D graphene-type structures. These fundamental reaction mechanisms are crucial to facilitate an understanding of the origin and evolution of the molecular universe and, in particular, of carbon in our Galaxy.

  17. Preparation and electrochemistry of a pyrene-linked iron terpyridine and its anodic redox polymer

    International Nuclear Information System (INIS)

    Lin, Hsiao-Chu; Straus, Daniel A.; Johnson, Victoria Anne; Lu, Jia E.; Lopez, Louise; Terrill, Roger H.

    2012-01-01

    An iron(II)bis-terpyridine complex bearing 4′ pendant pyrenyl groups on each ligand (Fe(tpySCH 2 -pyr) 2 2+ ) was synthesized, characterized electrochemically and was shown to form a novel redox polymer via anodic electropolymerization. Immersion of glassy carbon electrodes into dilute acetonitrile solutions of the complex and then into clean electrolyte established that the complex will physisorb onto glassy carbon at 0.1 monolayer coverage from 500 μM solution. Anodic cyclic voltammetry of the pyrenyl iron compound revealed well-resolved Fe(II/III) centered redox waves near 0.9 V and an irreversible, pyrene centered oxidation at ca. 1.1 V. The Fe(II/III) waves grew in magnitude over time and persisted in fresh complex-free electrolyte indicating a surface electropolymerization reaction most likely mediated via the pyrene pendant groups, and exhibiting facile charge transport through a ca. 100 nm polymer film. Spectroelectrochemical analysis of Fe(tpySCH 2 -pyr) 2 (OTf) 2 films grown on indium–tin oxide transparent electrodes confirmed the presence of a Fe(II/III) redox-active film that has a nearly Nernstian response, but with a small Fe(II) component that does not oxidize interfacially.

  18. Distribution of sorbed phenanthrene and pyrene in different humic fractions of soils and importance of humin

    International Nuclear Information System (INIS)

    Pan, B.; Xing, B.S.; Liu, W.X.; Tao, S.; Lin, X.M.; Zhang, X.M.; Zhang, Y.X.; Xiao, Y.; Dai, H.C.; Yuan, H.S.

    2006-01-01

    Contributions of fulvic-humic acids (FA/HA) and humin (HM) to sorption of phenanthrene (PHE) and pyrene (PYR) in a soil were differentiated using a humic separation procedure after multi-concentration sorption experiments. It was found that the amount of solutes in FA/HA did not change significantly after 48 h, while that in HM increased continuously and slowly up to the end of the experimental period (720 h), indicating that HM was the main region for slow sorption. Based on the fitting results using Freundlich equation, it was found that nonlinearity of both solutes was greater in HM than in FA/HA, consistent with the sorption characteristics of individually extracted HA and HM in a separate experiment. The observed nonlinearity of the solute distribution was confirmed by using three other soil samples with organic carbon contents ranging from 0.7 to 7.9%. Distribution dynamics of PHE and PYR among various fractions were also discussed. - Humic fractionation after sorption experiment revealed that humin fraction is the main region for slow and nonlinear sorption of phenanthrene and pyrene

  19. Targeting pancreatic cancer with magneto-fluorescent theranostic gold nanoshells.

    Science.gov (United States)

    Chen, Wenxue; Ayala-Orozco, Ciceron; Biswal, Nrusingh C; Perez-Torres, Carlos; Bartels, Marc; Bardhan, Rizia; Stinnet, Gary; Liu, Xian-De; Ji, Baoan; Deorukhkar, Amit; Brown, Lisa V; Guha, Sushovan; Pautler, Robia G; Krishnan, Sunil; Halas, Naomi J; Joshi, Amit

    2014-01-01

    We report a magneto-fluorescent theranostic nanocomplex targeted to neutrophil gelatinase-associated lipocalin (NGAL) for imaging and therapy of pancreatic cancer. Gold nanoshells resonant at 810 nm were encapsulated in silica epilayers doped with iron oxide and the near-infrared (NIR) dye indocyanine green, resulting in theranostic gold nanoshells (TGNS), which were subsequently conjugated with antibodies targeting NGAL in AsPC-1-derived xenografts in nude mice. Anti-NGAL-conjugated TGNS specifically targeted pancreatic cancer cells in vitro and in vivo providing contrast for both NIR fluorescence and T2-weighted MRI with higher tumor contrast than can be obtained using long-circulating, but nontargeted, PEGylated nanoparticles. The nanocomplexes also enabled highly specific cancer cell death via NIR photothermal therapy in vitro. TGNS with embedded NIR and magnetic resonance contrasts can be specifically targeted to pancreatic cancer cells with expression of early disease marker NGAL, and enable molecularly targeted imaging and photothermal therapy.

  20. Conjugated polymers developed from alkynes

    Institute of Scientific and Technical Information of China (English)

    Yajing Liu; Jacky W.Y.Lam; Ben Zhong Tang

    2015-01-01

    The numerous merits of conjugated polymers(CPs) have encouraged scientists to develop a variety of synthetic routes to CPs with diverse structures and functionalities. Among the large scope of substrates,alkyne plays an important role in constructing polymers with conjugated backbones. In addition to some well-developed reactions including Glaser–Hay and Sonogashira coupling, azide/thiol-yne click reaction and cyclotrimerization, some novel alkyne-based reactions have also been explored such as oxidative polycoupling, decarbonylative polycoupling and multicomponent tandem polymerizations. his review focuses on the recent progress on the synthetic methodology of CPs in the last ive years using monomers with two or more triple bonds and some of their high-technological applications. Selected examples of materials properties of these CPs are given in this review, such as luorescence response to chemical or physical stimuli, magnetism, white light emission, cell imaging and bioprobing. Finally, a short perspective is raised in regard to the outlook of the preparation methodologies, functionalities as well as potential applications of CPs in the future.

  1. Subgap Absorption in Conjugated Polymers

    Science.gov (United States)

    Sinclair, M.; Seager, C. H.; McBranch, D.; Heeger, A. J; Baker, G. L.

    1991-01-01

    Along with X{sup (3)}, the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of materials. We have used PDS to measure the optical absorption spectra of the conjugated polymers poly(1,4-phenylene-vinylene) (and derivitives) and polydiacetylene-4BCMU in the spectral region from 0.55 eV to 3 eV. Our spectra show that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1 cm{sup {minus}1} to 10 cm{sup {minus}1}. In the region below 1 eV, overtones of C-H stretching modes were observed, indicating that further improvements in transparency in this spectral region might be achieved via deuteration of fluorination.

  2. Subgap absorption in conjugated polymers

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, M.; Seager, C.H. (Sandia National Labs., Albuquerque, NM (USA)); McBranch, D.; Heeger, A.J. (California Univ., Santa Barbara, CA (USA)); Baker, G.L. (Bell Communications Research, Inc., Red Bank, NJ (USA))

    1991-01-01

    Along with X{sup (3)}, the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of < 10{sup {minus}5}, Photothermal Deflection Spectroscopy (PDS) is ideal for determining the absorption coefficients of thin films of transparent'' materials. We have used PDS to measure the optical absorption spectra of the conjugated polymers poly(1,4-phenylene-vinylene) (and derivitives) and polydiacetylene-4BCMU in the spectral region from 0.55 eV to 3 eV. Our spectra show that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1 cm{sup {minus}1} to 10 cm{sup {minus}1}. In the region below 1 eV, overtones of C-H stretching modes were observed, indicating that further improvements in transparency in this spectral region might be achieved via deuteration of fluorination. 11 refs., 4 figs.

  3. Reviews in fluorescence 2010

    CERN Document Server

    Geddes, Chris D

    2011-01-01

    ""Reviews in Fluorescence 2010"", the seventh volume of the book serial from Springer, serves as a comprehensive collection of current trends and emerging hot topics in the field of fluorescence and closely related disciplines. It summarizes the year's progress in fluorescence and its applications, with authoritative analytical reviews specialized enough to be attractive to professional researchers, yet also appealing to the wider audience of scientists in related disciplines of fluorescence. ""Reviews in Fluorescence"" offers an essential reference material for any lab working in the fluoresc

  4. Principles of fluorescence techniques

    CERN Document Server

    2016-01-01

    Fluorescence techniques are being used and applied increasingly in academics and industry. The Principles of Fluorescence Techniques course will outline the basic concepts of fluorescence techniques and the successful utilization of the currently available commercial instrumentation. The course is designed for students who utilize fluorescence techniques and instrumentation and for researchers and industrial scientists who wish to deepen their knowledge of fluorescence applications. Key scientists in the field will deliver theoretical lectures. The lectures will be complemented by the direct utilization of steady-state and lifetime fluorescence instrumentation and confocal microscopy for FLIM and FRET applications provided by leading companies.

  5. [Fluorescence spectra analysis of the scrophularia soup].

    Science.gov (United States)

    Yan, Li-hua; Song, Feng; Han, Juan; Su, Jing; Qu, Fei-fei; Song, Yi-zhan; Hu, Bo-lin; Tian, Jian-guo

    2008-08-01

    The cold-water and boiled-water soaked scrophularia soups have been prepared. The emission and excitation spectra of each scrophularia soup under different conditions have been measured at room temperature. The pH values of the different scrophularia soups have been also detected. There are obvious differences between the cold-water soaked scrophularia soup and the boiled-water soaked scrophularia. For both soups the emission wavelength increases with the wavelength of the excitation, but the peaks of the emission spectra for cold-water and boiled-water soaked scrophularia soup are different, which are 441 and 532 nm, respectively. Excitation spectrum has double peaks in the cold-water soaked scrophularia soup while only one peak with longer wavelength in the boiled-water soaked one. The pH value changes from 5.5 to 4.1. According to the organic admixture fluorescence mechanism we analyzed the reasons of the experimental results. Through heating, the interaction in different fluorescence molecular and the energy transfer process in the same fluorescence molecular become more active, and the conjugate structures and the generation of hydrogen bonds, increase. The fluorescence measurement is of value for the scrophularia pharmacology analysis and provides an analytical method for the quality identification of scrophularia soup.

  6. Fluorescent nanodiamonds embedded in biocompatible translucent shells.

    Science.gov (United States)

    Rehor, Ivan; Slegerova, Jitka; Kucka, Jan; Proks, Vladimir; Petrakova, Vladimira; Adam, Marie-Pierre; Treussart, François; Turner, Stuart; Bals, Sara; Sacha, Pavel; Ledvina, Miroslav; Wen, Amy M; Steinmetz, Nicole F; Cigler, Petr

    2014-03-26

    High pressure high temperature (HPHT) nanodiamonds (NDs) represent extremely promising materials for construction of fluorescent nanoprobes and nanosensors. However, some properties of bare NDs limit their direct use in these applications: they precipitate in biological solutions, only a limited set of bio-orthogonal conjugation techniques is available and the accessible material is greatly polydisperse in shape. In this work, we encapsulate bright 30-nm fluorescent nanodiamonds (FNDs) in 10-20-nm thick translucent (i.e., not altering FND fluorescence) silica shells, yielding monodisperse near-spherical particles of mean diameter 66 nm. High yield modification of the shells with PEG chains stabilizes the particles in ionic solutions, making them applicable in biological environments. We further modify the opposite ends of PEG chains with fluorescent dyes or vectoring peptide using click chemistry. High conversion of this bio-orthogonal coupling yielded circa 2000 dye or peptide molecules on a single FND. We demonstrate the superior properties of these particles by in vitro interaction with human prostate cancer cells: while bare nanodiamonds strongly aggregate in the buffer and adsorb onto the cell membrane, the shell encapsulated NDs do not adsorb nonspecifically and they penetrate inside the cells. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Preconditioning the modified conjugate gradient method ...

    African Journals Online (AJOL)

    In this paper, the convergence analysis of the conventional conjugate Gradient method was reviewed. And the convergence analysis of the modified conjugate Gradient method was analysed with our extension on preconditioning the algorithm. Convergence of the algorithm is a function of the condition number of M-1A.

  8. DENDRIMER CONJUGATES FOR SELECTIVE OF PROTEIN AGGREGATES

    DEFF Research Database (Denmark)

    2004-01-01

    Dendrimer conjugates are presented, which are formed between a dendrimer and a protein solubilising substance. Such dendrimer conjugates are effective in the treatment of protein aggregate-related diseases (e.g. prion-related diseases). The protein solubilising substance and the dendrimer together...

  9. Tetrafullerene conjugates for all-organic photovoltaics

    NARCIS (Netherlands)

    Fernández, G.; Sánchez, L.; Veldman, D.; Wienk, M.M.; Atienza, C.M.; Guldi, D.M.; Janssen, R.A.J.; Martin, N.

    2008-01-01

    The synthesis of two new tetrafullerene nanoconjugates in which four C60 units are covalently connected through different -conjugated oligomers (oligo(p-phenylene ethynylene) and oligo(p-phenylene vinylene)) is described. The photovoltaic (PV) response of these C60-based conjugates was evaluated by

  10. CONJUGATED BLOCK-COPOLYMERS FOR ELECTROLUMINESCENT DIODES

    NARCIS (Netherlands)

    Hilberer, A; Gill, R.E; Herrema, J.K; Malliaras, G.G; Wildeman, J.; Hadziioannou, G

    In this article we review results obtained in our laboratory on the design and study of new light-emitting polymers. We are interested in the synthesis and characterisation of block copolymers with regularly alternating conjugated and non conjugated sequences. The blocks giving rise to luminescence

  11. The Conjugate Acid-Base Chart.

    Science.gov (United States)

    Treptow, Richard S.

    1986-01-01

    Discusses the difficulties that beginning chemistry students have in understanding acid-base chemistry. Describes the use of conjugate acid-base charts in helping students visualize the conjugate relationship. Addresses chart construction, metal ions, buffers and pH titrations, and the organic functional groups and nonaqueous solvents. (TW)

  12. Class, Kinship Density, and Conjugal Role Segregation.

    Science.gov (United States)

    Hill, Malcolm D.

    1988-01-01

    Studied conjugal role segregation in 150 married women from intact families in working-class community. Found that, although involvement in dense kinship networks was associated with conjugal role segregation, respondents' attitudes toward marital roles and phase of family cycle when young children were present were more powerful predictors of…

  13. Misonidazole-glutathione conjugates in CHO cells

    International Nuclear Information System (INIS)

    Varghese, A.J.; Whitmore, G.F.

    1984-01-01

    Misonidazole, after reduction to the hydroxylamine derivative, reacts with glutathione (GSH) under physiological conditions. The reaction product has been identified as a mixture of two isomeric conjugates. When water soluble extracts of CHO cells exposed to misonidazole under hypoxic conditions are subjected to HPLC analysis, misonidazole derivatives, having the same chromatographic properties as the GSH-MISO conjugates, were detected. When CHO cells were incubated with misonidazole in the presence of added GSH, a substantial increase in the amount of the conjugate was detected. When extracts of CHO cells exposed to misonidazole under hypoxia were subsequently exposed to GSH, an increased formation of the conjugate was observed. A rearrangement product of the hydroxylamine derivative of misonidazole is postulated as the reactive intermediate responsible for the formation of the conjugate

  14. Approximate error conjugation gradient minimization methods

    Science.gov (United States)

    Kallman, Jeffrey S

    2013-05-21

    In one embodiment, a method includes selecting a subset of rays from a set of all rays to use in an error calculation for a constrained conjugate gradient minimization problem, calculating an approximate error using the subset of rays, and calculating a minimum in a conjugate gradient direction based on the approximate error. In another embodiment, a system includes a processor for executing logic, logic for selecting a subset of rays from a set of all rays to use in an error calculation for a constrained conjugate gradient minimization problem, logic for calculating an approximate error using the subset of rays, and logic for calculating a minimum in a conjugate gradient direction based on the approximate error. In other embodiments, computer program products, methods, and systems are described capable of using approximate error in constrained conjugate gradient minimization problems.

  15. Modelling conjugation with stochastic differential equations

    DEFF Research Database (Denmark)

    Philipsen, Kirsten Riber; Christiansen, Lasse Engbo; Hasman, Henrik

    2010-01-01

    Enterococcus faecium strains in a rich exhaustible media. The model contains a new expression for a substrate dependent conjugation rate. A maximum likelihood based method is used to estimate the model parameters. Different models including different noise structure for the system and observations are compared......Conjugation is an important mechanism involved in the transfer of resistance between bacteria. In this article a stochastic differential equation based model consisting of a continuous time state equation and a discrete time measurement equation is introduced to model growth and conjugation of two...... using a likelihood-ratio test and Akaike's information criterion. Experiments indicating conjugation on the agar plates selecting for transconjugants motivates the introduction of an extended model, for which conjugation on the agar plate is described in the measurement equation. This model is compared...

  16. Reviews in fluorescence 2008

    CERN Document Server

    Geddes, Chris D

    2010-01-01

    This volume serves as a comprehensive collection of current trends and emerging hot topics in the field of fluorescence spectroscopy. It summarizes the year's progress in fluorescence and its applications as well as includes authoritative analytical reviews.

  17. Fluorescent optical position sensor

    Science.gov (United States)

    Weiss, Jonathan D.

    2005-11-15

    A fluorescent optical position sensor and method of operation. A small excitation source side-pumps a localized region of fluorescence at an unknown position along a fluorescent waveguide. As the fluorescent light travels down the waveguide, the intensity of fluorescent light decreases due to absorption. By measuring with one (or two) photodetectors the attenuated intensity of fluorescent light emitted from one (or both) ends of the waveguide, the position of the excitation source relative to the waveguide can be determined by comparing the measured light intensity to a calibrated response curve or mathematical model. Alternatively, excitation light can be pumped into an end of the waveguide, which generates an exponentially-decaying continuous source of fluorescent light along the length of the waveguide. The position of a photodetector oriented to view the side of the waveguide can be uniquely determined by measuring the intensity of the fluorescent light emitted radially at that location.

  18. Dielectrophoresis of gold nanoparticles conjugated to DNA origami structures

    Directory of Open Access Journals (Sweden)

    Anja Henning-Knechtel

    2016-07-01

    Full Text Available DNA nanostructures are promising construction materials to bridge the gap between self-assembly of functional molecules and conventional top-down fabrication methods in nanotechnology. Their positioning onto specific locations of a microstructured substrate is an important task towards this aim. Here we study manipulation and positioning of pristine and of gold nanoparticle-conjugated tubular DNA origami structures using ac dielectrophoresis. The dielectrophoretic behavior was investigated employing fluorescence microscopy. For the pristine origami, a significant dielectrophoretic response was found to take place in the megahertz range, whereas, due to the higher polarizability of the metallic nanoparticles, the nanoparticle/DNA hybrid structures required a lower electrical field strength and frequency for a comparable trapping at the edges of the electrode structure. The nanoparticle conjugation additionally resulted in a remarkable alteration of the DNA structure arrangement. The growth of linear, chain-like structures in between electrodes at applied frequencies in the megahertz range was observed. The long-range chain formation is caused by a local, gold nanoparticle-induced field concentration along the DNA nanostructures, which in turn, creates dielectrophoretic forces that enable the observed self-alignment of the hybrid structures.

  19. Genetic engineering and chemical conjugation of potato virus X.

    Science.gov (United States)

    Lee, Karin L; Uhde-Holzem, Kerstin; Fischer, Rainer; Commandeur, Ulrich; Steinmetz, Nicole F

    2014-01-01

    Here we report the genetic engineering and chemical modification of potato virus X (PVX) for the presentation of various peptides, proteins, and fluorescent dyes, or other chemical modifiers. Three different ways of genetic engineering are described and by these means, peptides are successfully expressed not only when the foot and mouth disease virus (FMDV) 2A sequence or a flexible glycine-serine linker is included, but also when the peptide is fused directly to the PVX coat protein. When larger proteins or unfavorable peptide sequences are presented, a partial fusion via the FMDV 2A sequence is preferable. When these PVX chimeras retain the ability to assemble into viral particles and are thus able to infect plants systemically, they can be utilized to inoculate susceptible plants for isolation of sufficient amounts of virus particles for subsequent chemical modification. Chemical modification is required for the display of nonbiological ligands such as fluorophores, polymers, and small drug compounds. We present three methods of chemical bioconjugation. For direct conjugation of small chemical modifiers to solvent exposed lysines, N-hydroxysuccinimide chemistry can be applied. Bio-orthogonal reactions such as copper-catalyzed azide-alkyne cycloaddition or hydrazone ligation are alternatives to achieve more efficient conjugation (e.g., when working with high molecular weight or insoluble ligands). Furthermore, hydrazone ligation offers an attractive route for the introduction of pH-cleavable cargos (e.g., therapeutic molecules).

  20. Safe biodegradable fluorescent particles

    Science.gov (United States)

    Martin, Sue I [Berkeley, CA; Fergenson, David P [Alamo, CA; Srivastava, Abneesh [Santa Clara, CA; Bogan, Michael J [Dublin, CA; Riot, Vincent J [Oakland, CA; Frank, Matthias [Oakland, CA

    2010-08-24

    A human-safe fluorescence particle that can be used for fluorescence detection instruments or act as a safe simulant for mimicking the fluorescence properties of microorganisms. The particle comprises a non-biological carrier and natural fluorophores encapsulated in the non-biological carrier. By doping biodegradable-polymer drug delivery microspheres with natural or synthetic fluorophores, the desired fluorescence can be attained or biological organisms can be simulated without the associated risks and logistical difficulties of live microorganisms.

  1. Structures of benzo(a)pyrene-nucleic acid adducts formed in human and bovine bronchial explants

    DEFF Research Database (Denmark)

    Jeffrey, A.M.; Weinstein, I.B.; Jenette, K.W.

    1977-01-01

    PUBLICATION by Sims et al. of evidence that the 7,8-dihydrodiol-9,10-oxide of benzo(a)pyrene (BP) is a metabolic intermediate in the covalent binding of this ubiquitous polycyclic aromatic hydrocarbon to DNA in hamster embryo cells1 was followed by many related publications2. Grover et al. 3 also...

  2. [Effect of different soil types on the remediation of copper-pyrene compound contaminated soils by EK-oxidation process].

    Science.gov (United States)

    Fan, Guang-Ping; Cang, Long; Zhou, Dong-Mei; Zhou, Li-Xiang

    2011-11-01

    The effect of different soil types (red soil,yellow-brown soil and black soil) on the electrokinetic (EK)-oxidation remediation of heavy metals-organic pollutant contaminated soil was studied in laboratory-scale experiments. Copper and pyrene were chosen as model pollutant, and 12% H2O2, 10% hydroxypropyl-beta-cyclodextrin and 0.01 mol x L(-1) NaNO3 solution were added into the anode and cathode cell. The applied voltage was 1 V x cm(-1). After 15 days of EK remediation, the removal rate of pyrene and copper in red soil, yellow-brown soil and black soil were 38.5%, 46.8%, 51.3% for pyrene and 85.0%, 22.6%, 24.1% for Cu, respectively. The high pH of black soil produced high electroosmotic flow and increased the exposure of oxidants and pollutants, meanwhile the low clay content was also conducive to the desorption of pyrene. The low pH and organic matter of red soil affected the chemical species distribution of Cu and increased its removal rate. It is concluded that soil pH, clay content and heavy metal speciation in soil are the dominant factors affecting the migration and removal efficiency of pollutants.

  3. Photoinduced toxicity of three polycyclic aromatic hydrocarbons (fluoranthene, pyrene, and naphthalene) to the duckweed Lemna gibba L. G-3

    International Nuclear Information System (INIS)

    Ren, L.; Huang, X.D.; McConkey, B.J.; Dixon, D.G.; Greenberg, B.M.

    1994-01-01

    The authors recently demonstrated that light dramatically enhances the hazards of three polycyclic aromatic hydrocarbons (PAHs), anthracene, phenanthrene, and benzo[a]pyrene, to the duckweed Lemna gibba L. G-3 (X.-D. Huang, D. G. Dixon, and B. M. Greenberg, 1993, Environ. Toxicol. Chem., 12, 1067-1077). To extend this research, growth and chlorosis were used as end points to assess the photoinduced toxicity of three additional PAHs, fluoranthene, pyrene, and naphthalene, to L. gibba in the presence of simulated solar radiation (a light source with a UV-B: UV-A:visible light ratio equivalent to that of sunlight). The phytotoxicity of these three PAHs was photoactivated, with ultraviolet radiation being the only spectral region that enhanced the harmful effects of the chemicals. Dose-response curves based on chemical concentration and light intensity revealed that the order of phytotoxic strength was fluoranthene > pyrene > naphthalene. To explore whether photomodification (in addition to photosensitization) of fluoranthene, pyrene, and naphthalene could contribute to photoinduced toxicity, the chemicals were irradiated prior to (as opposed to simultaneously with) application to the plans. The rates of photomodification of the three PAHs were rapid enough for the photooxidized compounds to contribute to toxicity, and the photomodified PAHs were more toxic than the parent compounds. As well, toxicity could be correlated to photomodification; impacts increased in parallel with the extent of photomodification

  4. Benzo[a]pyrene co-metabolism in the presence of plant root extracts and exudates: Implications for phytoremediation

    Energy Technology Data Exchange (ETDEWEB)

    Rentz, Jeremy A [Civil and Environmental Engineering, University of Iowa, Iowa City, IA 52242 (United States); Alvarez, Pedro J.J. [Civil and Environmental Engineering, Rice University, Houston, TX 77251 (United States); Schnoor, Jerald L [Civil and Environmental Engineering, University of Iowa, Iowa City, IA 52242 (United States)

    2005-08-15

    Benzo[a]pyrene, a high molecular weight (HMW) polycyclic aromatic hydrocarbon (PAH) was removed from solution by Sphingomonas yanoikuyae JAR02 while growing on root products as a primary carbon and energy source. Plant root extracts of osage orange (Maclura pomifera), hybrid willow (Salix albaxmatsudana), or kou (Cordia subcordata), or plant root exudates of white mulberry (Morus alba) supported 15-20% benzo[a]pyrene removal over 24 h that was similar to a succinate grown culture and an unfed acetonitrile control. No differences were observed between the different root products tested. Mineralization of {sup 14}C-7-benzo[a]pyrene by S. yanoikuyae JAR02 yielded 0.2 to 0.3% {sup 14}CO{sub 2} when grown with plant root products. Collectively, these observations were consistent with field observations of enhanced phytoremediation of HMW PAH and corroborated the hypothesis that co-metabolism may be a plant/microbe interaction important to rhizoremediation. However, degradation and mineralization was much less for root product-exposed cultures than salicylate-induced cultures, and suggested the rhizosphere may not be an optimal environment for HMW PAH degradation by Sphingomonas yanoikuyae JAR02. - Bacterial benzo[a]pyrene cometabolism, a plant-microbe interaction affecting polycyclic aromatic hydrocarbon phytoremediation was demonstrated with Sphingomonas yanoikuyae JAR02 that utilized plant root extracts and exudates as primary substrates.

  5. Benzo[a]pyrene co-metabolism in the presence of plant root extracts and exudates: Implications for phytoremediation

    International Nuclear Information System (INIS)

    Rentz, Jeremy A.; Alvarez, Pedro J.J.; Schnoor, Jerald L.

    2005-01-01

    Benzo[a]pyrene, a high molecular weight (HMW) polycyclic aromatic hydrocarbon (PAH) was removed from solution by Sphingomonas yanoikuyae JAR02 while growing on root products as a primary carbon and energy source. Plant root extracts of osage orange (Maclura pomifera), hybrid willow (Salix albaxmatsudana), or kou (Cordia subcordata), or plant root exudates of white mulberry (Morus alba) supported 15-20% benzo[a]pyrene removal over 24 h that was similar to a succinate grown culture and an unfed acetonitrile control. No differences were observed between the different root products tested. Mineralization of 14 C-7-benzo[a]pyrene by S. yanoikuyae JAR02 yielded 0.2 to 0.3% 14 CO 2 when grown with plant root products. Collectively, these observations were consistent with field observations of enhanced phytoremediation of HMW PAH and corroborated the hypothesis that co-metabolism may be a plant/microbe interaction important to rhizoremediation. However, degradation and mineralization was much less for root product-exposed cultures than salicylate-induced cultures, and suggested the rhizosphere may not be an optimal environment for HMW PAH degradation by Sphingomonas yanoikuyae JAR02. - Bacterial benzo[a]pyrene cometabolism, a plant-microbe interaction affecting polycyclic aromatic hydrocarbon phytoremediation was demonstrated with Sphingomonas yanoikuyae JAR02 that utilized plant root extracts and exudates as primary substrates

  6. Optimization of fluorescent proteins

    NARCIS (Netherlands)

    Bindels, D.S.; Goedhart, J.; Hink, M.A.; van Weeren, L.; Joosen, L.; Gadella (jr.), T.W.J.; Engelborghs, Y.; Visser, A.J.W.G.

    2014-01-01

    Nowadays, fluorescent protein (FP) variants have been engineered to fluoresce in all different colors; to display photoswitchable, or photochromic, behavior; or to show yet other beneficial properties that enable or enhance a still growing set of new fluorescence spectroscopy and microcopy

  7. 6-Aminocoumarin-naphthoquinone conjugates: design, synthesis, photophysical and electrochemical properties and DFT calculations

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Fabio S.; Ronconi, Celia M.; Sousa, Mikaelly O.B.; Silveira, Gleiciani Q.; Vargas, Maria D., E-mail: miranda@vm.uff.br, E-mail: mdvargascp@gmail.com [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Quimica

    2014-01-15

    Four novel 6-aminocoumarin-naphthoquinone conjugates were synthesized and their photophysical and electrochemical properties, investigated. 2-Chloro-3-(2-oxo-2H-chromen-6- ylamino)-1,4-naphthoquinone 1 did not present appreciable fluorescence in solution in comparison with 6-aminocoumarin, 6-AC. In order to understand the reasons for the fluorescence quenching in this compound, two strategies were attempted. Firstly, compound 1 was N-methylated to remove the intramolecular N-H...O=C electrostatic interaction that maintained the two units fixed, but the emission properties of the product 2 were not significantly different from those of 1. Time-dependent density functional theory (TD-DFT) calculations of compounds 1 and 2 indicate that the fluorescence quenching is related to the electron acceptor character of the naphthoquinone ring. The second strategy, therefore, involved the substitution of the chlorine atom in position 2 of the naphthoquinone nucleus for different electron donor groups (compounds 3-5), but again the emission properties did not change significantly. To explain these experimental findings, TD-DFT calculations of the ground (S{sub 0}) and excited (S{sub 1}) states of all molecules in solution were carried out. The results suggest that the energy states in these conjugates are such that the fluorescent group (6-AC) donates electrons to the naphthoquinone LUMO resulting in an oxidative photoinduced electron transfer (oxidative-PET). (author)

  8. 25 years and still going strong: 2'-O-(pyren-1-yl)methylribonucleotides - versatile building blocks for applications in molecular biology, diagnostics and materials science.

    Science.gov (United States)

    Hrdlicka, Patrick J; Karmakar, Saswata

    2017-11-29

    Oligonucleotides (ONs) modified with 2'-O-(pyren-1-yl)methylribonucleotides have been explored for a range of applications in molecular biology, nucleic acid diagnostics, and materials science for more than 25 years. The first part of this review provides an overview of synthetic strategies toward 2'-O-(pyren-1-yl)methylribonucleotides and is followed by a summary of biophysical properties of nucleic acid duplexes modified with these building blocks. Insights from structural studies are then presented to rationalize the reported properties. In the second part, applications of ONs modified with 2'-O-(pyren-1-yl)methyl-RNA monomers are reviewed, which include detection of RNA targets, discrimination of single nucleotide polymorphisms, formation of self-assembled pyrene arrays on nucleic acid scaffolds, the study of charge transfer phenomena in nucleic acid duplexes, and sequence-unrestricted recognition of double-stranded DNA. The predictable binding mode of the pyrene moiety, coupled with the microenvironment-dependent properties and synthetic feasibility, render 2'-O-(pyren-1-yl)methyl-RNA monomers as a promising class of pyrene-functionalized nucleotide building blocks for new applications in molecular biology, nucleic acid diagnostics, and materials science.

  9. CD33 monoclonal antibody conjugated Au cluster nano-bioprobe for targeted flow-cytometric detection of acute myeloid leukaemia

    Science.gov (United States)

    Retnakumari, Archana; Jayasimhan, Jasusri; Chandran, Parwathy; Menon, Deepthy; Nair, Shantikumar; Mony, Ullas; Koyakutty, Manzoor

    2011-07-01

    Protein stabilized gold nanoclusters (Au-NCs) are biocompatible, near-infrared (NIR) emitting nanosystems having a wide range of biomedical applications. Here, we report the development of a Au-NC based targeted fluorescent nano-bioprobe for the flow-cytometric detection of acute myeloid leukaemia (AML) cells. Au-NCs with ~ 25-28 atoms showing bright red-NIR fluorescence (600-750 nm) and average size of ~ 0.8 nm were prepared by bovine serum albumin assisted reduction-cum-stabilization in aqueous phase. The protein protected clusters were conjugated with monoclonal antibody against CD33 myeloid antigen, which is overexpressed in ~ 99.2% of the primitive population of AML cells, as confirmed by immunophenotyping using flow cytometry. Au-NC-CD33 conjugates having average size of ~ 12 nm retained bright fluorescence over an extended duration of ~ a year, as the albumin protein protects Au-NCs against degradation. Nanotoxicity studies revealed excellent biocompatibility of Au-NC conjugates, as they showed no adverse effect on the cell viability and inflammatory response. Target specificity of the conjugates for detecting CD33 expressing AML cells (KG1a) in flow cytometry showed specific staining of ~ 95.4% of leukaemia cells within 1-2 h compared to a non-specific uptake of ~ 8.2% in human peripheral blood cells (PBMCs) which are CD33low. The confocal imaging also demonstrated the targeted uptake of CD33 conjugated Au-NCs by leukaemia cells, thus confirming the flow cytometry results. This study demonstrates that novel nano-bioprobes can be developed using protein protected fluorescent nanoclusters of Au for the molecular receptor targeted flow cytometry based detection and imaging of cancer cells.

  10. CD33 monoclonal antibody conjugated Au cluster nano-bioprobe for targeted flow-cytometric detection of acute myeloid leukaemia

    International Nuclear Information System (INIS)

    Retnakumari, Archana; Jayasimhan, Jasusri; Chandran, Parwathy; Menon, Deepthy; Nair, Shantikumar; Mony, Ullas; Koyakutty, Manzoor

    2011-01-01

    Protein stabilized gold nanoclusters (Au-NCs) are biocompatible, near-infrared (NIR) emitting nanosystems having a wide range of biomedical applications. Here, we report the development of a Au-NC based targeted fluorescent nano-bioprobe for the flow-cytometric detection of acute myeloid leukaemia (AML) cells. Au-NCs with ∼ 25-28 atoms showing bright red-NIR fluorescence (600-750 nm) and average size of ∼ 0.8 nm were prepared by bovine serum albumin assisted reduction-cum-stabilization in aqueous phase. The protein protected clusters were conjugated with monoclonal antibody against CD33 myeloid antigen, which is overexpressed in ∼ 99.2% of the primitive population of AML cells, as confirmed by immunophenotyping using flow cytometry. Au-NC-CD33 conjugates having average size of ∼ 12 nm retained bright fluorescence over an extended duration of ∼ a year, as the albumin protein protects Au-NCs against degradation. Nanotoxicity studies revealed excellent biocompatibility of Au-NC conjugates, as they showed no adverse effect on the cell viability and inflammatory response. Target specificity of the conjugates for detecting CD33 expressing AML cells (KG1a) in flow cytometry showed specific staining of ∼ 95.4% of leukaemia cells within 1-2 h compared to a non-specific uptake of ∼ 8.2% in human peripheral blood cells (PBMCs) which are CD33 low . The confocal imaging also demonstrated the targeted uptake of CD33 conjugated Au-NCs by leukaemia cells, thus confirming the flow cytometry results. This study demonstrates that novel nano-bioprobes can be developed using protein protected fluorescent nanoclusters of Au for the molecular receptor targeted flow cytometry based detection and imaging of cancer cells.

  11. CD33 monoclonal antibody conjugated Au cluster nano-bioprobe for targeted flow-cytometric detection of acute myeloid leukaemia

    Energy Technology Data Exchange (ETDEWEB)

    Retnakumari, Archana; Jayasimhan, Jasusri; Chandran, Parwathy; Menon, Deepthy; Nair, Shantikumar; Mony, Ullas; Koyakutty, Manzoor, E-mail: manzoork@aims.amrita.edu, E-mail: ullasmony@aims.amrita.edu [Amrita Centre for Nanoscience and Molecular Medicine, Amrita Institute of Medical Science, Cochin 682 041 (India)

    2011-07-15

    Protein stabilized gold nanoclusters (Au-NCs) are biocompatible, near-infrared (NIR) emitting nanosystems having a wide range of biomedical applications. Here, we report the development of a Au-NC based targeted fluorescent nano-bioprobe for the flow-cytometric detection of acute myeloid leukaemia (AML) cells. Au-NCs with {approx} 25-28 atoms showing bright red-NIR fluorescence (600-750 nm) and average size of {approx} 0.8 nm were prepared by bovine serum albumin assisted reduction-cum-stabilization in aqueous phase. The protein protected clusters were conjugated with monoclonal antibody against CD33 myeloid antigen, which is overexpressed in {approx} 99.2% of the primitive population of AML cells, as confirmed by immunophenotyping using flow cytometry. Au-NC-CD33 conjugates having average size of {approx} 12 nm retained bright fluorescence over an extended duration of {approx} a year, as the albumin protein protects Au-NCs against degradation. Nanotoxicity studies revealed excellent biocompatibility of Au-NC conjugates, as they showed no adverse effect on the cell viability and inflammatory response. Target specificity of the conjugates for detecting CD33 expressing AML cells (KG1a) in flow cytometry showed specific staining of {approx} 95.4% of leukaemia cells within 1-2 h compared to a non-specific uptake of {approx} 8.2% in human peripheral blood cells (PBMCs) which are CD33{sup low}. The confocal imaging also demonstrated the targeted uptake of CD33 conjugated Au-NCs by leukaemia cells, thus confirming the flow cytometry results. This study demonstrates that novel nano-bioprobes can be developed using protein protected fluorescent nanoclusters of Au for the molecular receptor targeted flow cytometry based detection and imaging of cancer cells.

  12. Further characterization of benzo[a]pyrene diol-epoxide (BPDE)-induced comet assay effects.

    Science.gov (United States)

    Bausinger, Julia; Schütz, Petra; Piberger, Ann Liza; Speit, Günter

    2016-03-01

    The present study aims to further characterize benzo[a]pyrene diol-epoxide (BPDE)-induced comet assay effects. Therefore, we measured DNA effects by the comet assay and adduct levels by high-performance liquid chromatography (HPLC) in human lymphocytes and A549 cells exposed to (±)-anti-benzo[a]pyrene-7,8-diol 9,10-epoxide [(±)-anti-BPDE] or (+)-anti-benzo[a]pyrene-7,8-diol 9,10-epoxide [(+)-anti-BPDE]. Both, the racemic form and (+)-anti-BPDE, which is the most relevant metabolite with regard to mutagenicity and carcinogenicity, induced DNA migration in cultured lymphocytes in the same range of concentrations to a similar extent in the alkaline comet assay after exposure for 2h. Nevertheless, (+)-anti-BPDE induced significantly enhanced DNA migration after 16 and 18h post-cultivation which was not seen in response to (±)-anti-BPDE. Combination of the comet assay with the Fpg (formamidopyrimidine-DNA glycosylase) protein did not enhance BPDE-induced effects and thus indicated the absence of Fpg-sensitive sites (oxidized purines, N7-guanine adducts, AP-sites). The aphidicolin (APC)-modified comet assay suggested significant excision repair activity of cultured lymphocytes during the first 18h of culture after a 2 h-exposure to BPDE. In contrast to these repair-related effects measured by the comet assay, HPLC analysis of stable adducts did not reveal any significant removal of (+)-anti-BPDE-induced adducts from lymphocytes during the first 22h of culture. On the other hand, HPLC measurements indicated that A549 cells repaired about 70% of (+)-anti-BPDE-induced DNA-adducts within 22h of release. However, various experiments with the APC-modified comet assay did not indicate significant repair activity during this period in A549 cells. The conflicting results obtained with the comet assay and the HPLC-based adduct analysis question the real cause for BPDE-induced DNA migration in the comet assay and the reliability of the APC-modified comet assay for the

  13. p53 Mutagenesis by Benzo[a]pyrene derived Radical Cations

    Science.gov (United States)

    Sen, Sushmita; Bhojnagarwala, Pratik; Francey, Lauren; Lu, Ding; Jeffrey Field, Trevor M. Penning

    2013-01-01

    Benzo[a]pyrene (B[a]P), a major human carcinogen in combustion products such as cigarette smoke and diesel exhaust, is metabolically activated into DNA-reactive metabolites via three different enzymatic pathways. The pathways are the anti-(+)-benzo[a]pyrene 7,8-diol 9, 10-epoxide pathway (P450/ epoxide hydrolase catalyzed) (B[a]PDE), the benzo[a]pyrene o-quinone pathway (aldo ketose reductase (AKR) catalyzed) and the B[a]P radical cation pathway (P450 peroxidase catalyzed). We used a yeast p53 mutagenesis system to assess mutagenesis by B[a]P radical cations. Because radical cations are short-lived, they were generated in situ by reacting B[a]P with cumene hydroperoxide (CuOOH) and horse radish peroxidase (HRP) and then monitoring the generation of the more stable downstream products, B[a]P-1,6-dione and B[a]P-3,6-dione. Based on the B[a]P-1,6 and 3,6-dione formation, approximately 4µM of radical cation was generated. In the mutagenesis assays, the radical cations produced in situ showed a dose-dependent increase in mutagenicity from 0.25 µM to 10 µM B[a]P with no significant increase seen with further escalation to 50 µM B[a]P. However, mutagenesis was 200-fold less than with the AKR pathway derived B[a]P, 7–8 dione. Mutant p53 plasmids, which yield red colonies, were recovered from the yeast to study the pattern and spectrum of mutations. The mutation pattern observed was G to T (31%) > G to C (29%) > G to A (14%). The frequency of codons mutated by the B[a]P radical cations was essentially random and not enriched at known cancer hotspots. The quinone products of radical cations, B[a]P-1,6-dione and B[a]P-3,6-dione were more mutagenic than the radical cation reactions, but still less mutagenic than AKR derived B[a]P-7,8-dione. We conclude that B[a]P radical cations and their quinone products are weakly mutagenic in this yeast-based system compared to redox cycling PAH o-quinones. PMID:22768918

  14. NIR photoregulated chemo- and photodynamic cancer therapy based on conjugated polyelectrolyte-drug conjugate encapsulated upconversion nanoparticles

    Science.gov (United States)

    Yuan, Youyong; Min, Yuanzeng; Hu, Qinglian; Xing, Bengang; Liu, Bin

    2014-09-01

    The design of nanoplatforms with target recognition and near-infrared (NIR) laser photoregulated chemo- and photodynamic therapy is highly desirable but remains challenging. In this work, we have developed such a system by taking advantage of a conjugated polyelectrolyte (CPE)-drug conjugate and upconversion nanoparticles (UCNPs). The poly(ethylene glycol) (PEG) grafted CPE not only serves as a polymer matrix for UCNP encapsulation, but also as a fluorescent imaging agent, a photosensitizer as well as a carrier for chemotherapeutic drug doxorubicin (DOX) through a UV-cleavable ortho-nitrobenzyl (NB) linker. Upon 980 nm laser irradiation, the UCNPs emit UV and visible light. The up-converted UV light is utilized for controlled drug release through the photocleavage of the ortho-nitrobenzyl linker, while the up-converted visible light is used to initiate the polymer photosensitizer to produce reactive oxygen species (ROS) for photodynamic therapy. The NIR photo-regulated UCNP@CPE-DOX showed high efficiency of ROS generation and controlled drug release in cancer cells upon single laser irradiation. In addition, the combination therapy showed enhanced inhibition of U87-MG cell growth as compared to sole treatments. As two light sources with different wavelengths are always needed for traditional photodynamic therapy and photoregulated drug release, the adoption of UCNPs as an NIR light switch is highly beneficial to combined chemo- and photodynamic therapy with enhanced therapeutic effects.

  15. Modulation of a fluorescence switch based on photochromic spirooxazine in composite organic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sheng Xiaohai [Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China); Peng Aidong [Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China); Fu Hongbing [Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China); Liu Yuanyuan [Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China); Zhao Yongsheng [Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China); Ma Ying [Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China); Yao Jiannian [Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China)

    2007-04-11

    We describe a versatile and convenient approach to achieve fluorescence modulation by the preparation of composite nanoparticles (CNPs), based on photochromic 5-methoxy-1,3,3-trimethyl-9'-hydroxyspiroindolinenaphthoxazine (SO), fluorescent 4-(dicyanomethylene)-2-methyl-6-(p-dimethyl-aminostyryl)-4H-pyran (DCM), and emissive-assistant 1,3-bis(pyrene) propane (BPP) molecules, employing doping techniques. The mechanism of the fluorescence switch is the intermolecular energy transfer as supported by both steady-state and time-resolved spectroscopy results. The addition of BPP not only enhances the contrast of the fluorescence signal between the 'ON' and 'OFF' state, but also provides a convenient way to tune the excitation wavelength for reading the fluorescence. High-contrast ON/OFF (20:1) fluorescence switching is successfully implemented in the CNPs and also in a more practical PVA film loaded with the CNPs. This system may represent an alternative to the covalent system in potentially rewritable high-density optical data or image storage utilizing luminescence intensity readout schemes.

  16. Modulation of a fluorescence switch based on photochromic spirooxazine in composite organic nanoparticles

    International Nuclear Information System (INIS)

    Sheng Xiaohai; Peng Aidong; Fu Hongbing; Liu Yuanyuan; Zhao Yongsheng; Ma Ying; Yao Jiannian

    2007-01-01

    We describe a versatile and convenient approach to achieve fluorescence modulation by the preparation of composite nanoparticles (CNPs), based on photochromic 5-methoxy-1,3,3-trimethyl-9'-hydroxyspiroindolinenaphthoxazine (SO), fluorescent 4-(dicyanomethylene)-2-methyl-6-(p-dimethyl-aminostyryl)-4H-pyran (DCM), and emissive-assistant 1,3-bis(pyrene) propane (BPP) molecules, employing doping techniques. The mechanism of the fluorescence switch is the intermolecular energy transfer as supported by both steady-state and time-resolved spectroscopy results. The addition of BPP not only enhances the contrast of the fluorescence signal between the 'ON' and 'OFF' state, but also provides a convenient way to tune the excitation wavelength for reading the fluorescence. High-contrast ON/OFF (20:1) fluorescence switching is successfully implemented in the CNPs and also in a more practical PVA film loaded with the CNPs. This system may represent an alternative to the covalent system in potentially rewritable high-density optical data or image storage utilizing luminescence intensity readout schemes

  17. Dual stimuli polysaccharide nanovesicles for conjugated and physically loaded doxorubicin delivery in breast cancer cells

    Science.gov (United States)

    Pramod, P. S.; Shah, Ruchira; Jayakannan, Manickam

    2015-04-01

    pyrene and Nile red with DEX-IM-10, FE-SEM image of DEX-IM-DOX loaded, FE-SEM image of acid treated DEX-IM-5, absorbance spectra of DOX released, in vitro DOX release from drug loaded and conjugated vesicles in the presence of serum (FBS), DLS data depicting stability of DEX-IM vesicles in serum (FBS), 1HNMR, 13C NMR and HR-MS spectra of all intermediates are provided. See DOI: 10.1039/c5nr00799b

  18. Ratiometric fluorescent receptors for both Zn2+ and H2PO4(-) ions based on a pyrenyl-linked triazole-modified homooxacalix[3]arene: a potential molecular traffic signal with an R-S latch logic circuit.

    Science.gov (United States)

    Ni, Xin-long; Zeng, Xi; Redshaw, Carl; Yamato, Takehiko

    2011-07-15

    A ratiometric fluorescent receptor with a C(3) symmetric structure based on a pyrene-linked triazole-modified homooxacalix[3]arene (L) was synthesized and characterized. This system exhibited an interesting ratiometric detection signal output for targeting cations and anions through switching the excimer emission of pyrene from the "on-off" to the "off-on" type in neutral solution. (1)H NMR titration results suggested that the Zn(2+) center of receptor L·Zn(2+) provided an excellent pathway of organizing anion binding groups for optimal host-guest interactions. It is thus believed that this receptor has potential application in sensing, detection, and recognition of both Zn(2+) and H(2)PO(4)(-) ions with different optical signals. In addition, the fluorescence emission changes by the inputs of Zn(2+) and H(2)PO(4)(-) ions can be viewed as a combinational R-S latch logic circuit at the molecular level.

  19. Investigation of common fluorophores for the detection of nitrated explosives by fluorescence quenching

    International Nuclear Information System (INIS)

    Meaney, Melissa S.; McGuffin, Victoria L.

    2008-01-01

    Previous studies have indicated that nitrated explosives may be detected by fluorescence quenching of pyrene and related compounds. The use of pyrene, however, invokes numerous health and waste disposal hazards. In the present study, ten safer fluorophores are identified for quenching detection of target nitrated compounds. Initially, Stern-Volmer constants are measured for each fluorophore with nitrobenzene and 4-nitrotoluene to determine the sensitivity of the quenching interaction. For quenching constants greater than 50 M -1 , sensitivity and selectivity are investigated further using an extended set of target quenchers. Nitromethane, nitrobenzene, 4-nitrotoluene, and 2,6-dinitrotoluene are chosen to represent nitrated explosives and their degradation products; aniline, benzoic acid, and phenol are chosen to represent potential interfering compounds. Among the fluorophores investigated, purpurin, malachite green, and phenol red demonstrate the greatest sensitivity and selectivity for nitrated compounds. Correlation of the quenching rate constants for these fluorophores to Rehm-Weller theory suggests an electron-transfer quenching mechanism. As a result of the large quenching constants, purpurin, malachite green, and phenol red are the most promising for future detection of nitrated explosives via fluorescence quenching

  20. Turn-On Fluorescent Chemosensor for Fluoride Based on Pyreneamide Derivative

    International Nuclear Information System (INIS)

    Jeon, Nam Joong; Hong, Sung Won; Hong, Ju Hyun; Jeong, Ju Mi; Nam, Kye Chun

    2012-01-01

    A new chemosensor with pyreneamide derivative of bipyridine is synthesized. In the free ligand, pyreneamide derivative has nearly no fluorescence in acetonitrile solution. However, in the presence of fluoride ion, a 'turn-on' fluorescence was observed. Simultaneously, the colorless ligand solution became markedly orange when fluoride ion was added to pyreneamide derivative in acetonitrile. This phenomenon suggest that the PET (photoinduced electron transfer) between anion electron and pyrene unit was changed the π-π interaction between bipyridine and pyrene that was modified structure by deprotonation. On account of the important roles of anion in biological, clinical, environmental, catalysis, and chemical processes, the selective and efficient recognition of anion is an area of growing interest in supramolecular chemistry. In particular, the studies of chemosensors toward F - anion are quite intriguing because of its beneficial effects in human physiology. Also, fluoride is interest due to its established role in dental care and osteoporosis. However, an excess of fluoride ion can lead to fluorosis. Therefore, the development of reliable sensors for F - is needed for environment and human health care. Color changes that can be detected by the naked eye are widely used as signals for events owing to the inexpensive equipment required or no equipment at all

  1. Turn-On Fluorescent Chemosensor for Fluoride Based on Pyreneamide Derivative

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Nam Joong; Hong, Sung Won; Hong, Ju Hyun; Jeong, Ju Mi; Nam, Kye Chun [Seoul National University, Seoul (Korea, Republic of)

    2012-01-15

    A new chemosensor with pyreneamide derivative of bipyridine is synthesized. In the free ligand, pyreneamide derivative has nearly no fluorescence in acetonitrile solution. However, in the presence of fluoride ion, a 'turn-on' fluorescence was observed. Simultaneously, the colorless ligand solution became markedly orange when fluoride ion was added to pyreneamide derivative in acetonitrile. This phenomenon suggest that the PET (photoinduced electron transfer) between anion electron and pyrene unit was changed the π-π interaction between bipyridine and pyrene that was modified structure by deprotonation. On account of the important roles of anion in biological, clinical, environmental, catalysis, and chemical processes, the selective and efficient recognition of anion is an area of growing interest in supramolecular chemistry. In particular, the studies of chemosensors toward F{sup -} anion are quite intriguing because of its beneficial effects in human physiology. Also, fluoride is interest due to its established role in dental care and osteoporosis. However, an excess of fluoride ion can lead to fluorosis. Therefore, the development of reliable sensors for F{sup -} is needed for environment and human health care. Color changes that can be detected by the naked eye are widely used as signals for events owing to the inexpensive equipment required or no equipment at all.

  2. Photophysical, Photochemical, and BQ Quenching Properties of Zinc Phthalocyanines with Fused or Interrupted Extended Conjugation

    Directory of Open Access Journals (Sweden)

    Gülşah Gümrükçü

    2014-01-01

    Full Text Available The effects of substituents and solvents on the photophysical and photochemical parameters of zinc(II phthalocyanines containing four Schiff’s base substituents attached directly and through phenyleneoxy-bridges on peripheral positions are reported. The group effects on peripheral position and the continual and intermittent conjugation of the phthalocyanine molecules on the photophysical and photochemical properties are also investigated. General trends are described for photodegradation, singlet oxygen, and fluorescence quantum yields of these compounds in dimethylsulfoxide (DMSO, dimethylformamide (DMF, and tetrahydrofurane (THF. Among the different substituents, phthalocyanines with cinnamaldimine moieties (1c and 2c have the highest singlet oxygen quantum yields (ΦΔ and those with nitro groups (1a and 2a have the highest fluorescence quantum yields in all the solvents used. The fluorescence of the substituted zinc(II phthalocyanine complexes is effectively quenched by 1,4-benzoquinone (BQ in these solvents.

  3. Sediment balance in four small catechumen's with different land cover in the Central Pyrenes (Spain)

    International Nuclear Information System (INIS)

    Nadal Romero, E.; Lana-Renault, N.; Serrano-Muela, P.; Reguez, D.; Alvera, B.; Latron, J.; Marti-Bono, C.; Garcia-Ruiz, J. M.

    2009-01-01

    Four experimental catchment s in the Central Pyrenes were monitored by the Department of Geo-environmental Processes and global Change (Pyrenean Institute of Ecology, CSIC) to assess the hydrological and geomprophological consequences of various land uses and vegetation cover. The catchments were selected along an attitudinal and land-use gradient and included: (i) a sub-Mediterranean environment affected by intense weathering and erosion processes on marls, (ii) an old abandoned cultivated area undergoing vegetation regrowth, (iii) a barely-disturbed forest area, and (iv) a sub-alpine grassland in the high mountains, affected by snow accumulation and melting processes. The results demonstrate that plant cover is a key factor influencing the suspended sediment concentration, total sediment yield and proportion of different types of sediment. (Author) 7 refs.

  4. Chlorophyll catalyse the photo-transformation of carcinogenic benzo[a]pyrene in water

    Science.gov (United States)

    Luo, Lijuan; Lai, Xueying; Chen, Baowei; Lin, Li; Fang, Ling; Tam, Nora F. Y.; Luan, Tiangang

    2015-01-01

    Algal blooms cause great damage to water quality and aquaculture. However, this study showed that dead algal cells and chlorophyll could accelerate the photo-transformation of benzo[a]pyrene (BaP), a ubiquitous and persistent pollutant with potently mutagenic and carcinogenic toxicities, under visible light irradiation. Chlorophyll was found to be the major active substance in dead algal cells, and generated a high level of singlet oxygen to catalyse the photo-transformation of BaP. According to various BaP metabolites formed, the degradation mechanism was proposed as that chlorophyll in dead algal cells photo-oxidized BaP to quinones via photocatalytic generation of singlet oxygen. The results provided a good insight into the role of chlorophyll in the photo-transformation of organic contaminants and could be a possible remediation strategy of organic pollutants in natural environment. PMID:26239357

  5. Combined effects of inhaled plutonium oxide and benzo[a]pyrene on lung carcinogenesis in rats

    International Nuclear Information System (INIS)

    Metivier, H.; Masse, R.; Wahrendorf, J.; Lafuma, J.

    1986-01-01

    This study describes the effect of two intratracheal instillations (5 mg each) of benzo[a]pyrene (BP) on lung carcinogenesis in rats that had previously inhaled three levels of 239 PuO 2 . The BP does not modify survival in the high-level 239 PuO 2 -exposed rats, but markedly reduces survival in the two other groups. Median survival time with BP alone is shorter (666 days) than for the control group (838 days). Tumor incidence was increased by BP exposure, and the tumors were usually fatal, whereas tumors observed after 239 PuO 2 inhalation alone were usually not fatal. Statistical analysis of these data poses a problem because of the need to compare incidental and fatal tumors. 22 refs., 5 figs., 7 tabs

  6. Determination of lead, zinc and benzo(a)pyrene in incineration flue gas

    International Nuclear Information System (INIS)

    Han Baohua; Gao Zhuqin; Guo Qian

    2003-01-01

    An analitical method was developed for the determination of lead(Pb), zinc(Zn) and benzo(a)pyrene (BaP) in flue gas of radwaste pyroysis incinerator, respectively using Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) and High Performance Liquid Chromatography (HPLC). The sample preparation and the influence of major components in back-ground were researched. Interference correction coefficient for Pb and Zn are given in this article. The recovery of Pb, Zn and BaP are all above 84.0% and the relative standard deviation (RSD) were 3.51% for Pb, 7.28% for Zn and 4.50% for BaP, respectively. It shows that this analytical method can meet the incineration processes. (authors)

  7. Explant culture of human peripheral lung. I. Metabolism of benzo[alpha]pyrene

    DEFF Research Database (Denmark)

    Stoner, G.D.; Harris, C.C.; Autrup, Herman

    1978-01-01

    the predominant alveolar epithelial cell type. Lamellar inclusion bodies were released from the type 2 cells and accumulated in the alveolar spaces. The metabolism of benzo[alpha]pyrene (BP) in human lung explants cultured for up to 7 days was investigated. Human lung explants had measurable aryl hydrocarbon......Human lung explants have been maintained in vitro for a period of 25 days. Autoradiographic studies indicated that the broncholar epithelial cells, type 2 alveolar epithelial cells, and stromal fibroblasts incorporated 3H-thymidine during the culture. After 7 to 10 days, type 2 cells were...... hydroxylase activity and could metabolize BP into forms that were bound to cellular DNA and protein. Peripheral lung had significantly lower aryl hydrocarbon hydroxylase activity than cultured bronchus but both tissues had similar binding levels of BP to DNA. Radioautographic studies indicated that all cell...

  8. Destruction of acenaphthene, fluorene, anthracene and pyrene by a dc gliding arc plasma reactor.

    Science.gov (United States)

    Yu, Liang; Tu, Xin; Li, Xiaodong; Wang, Yu; Chi, Yong; Yan, Jianhua

    2010-08-15

    In this study, four kinds of PAHs (polycyclic aromatic hydrocarbons) i.e. acenaphthene, fluorene, anthracene and pyrene are used as targets for investigation of PAHs treatment process assisted by dc gliding arc discharge. The effects of carrier gas and external resistance on the PAHs decomposition process are discussed. The results indicate that the destruction rate can be achieved to the highest with the carrier gas of oxygen and the external resistance of 50 kOmega independent of type of PAHs. Furthermore, experimental results suggest that destruction energy efficiency of gliding arc plasma would be improved by treating higher concentration pollutants. Based on the analysis of experimental results, possible destruction mechanisms in different gas discharge are discussed. Copyright 2010 Elsevier B.V. All rights reserved.

  9. Destruction of acenaphthene, fluorene, anthracene and pyrene by a dc gliding arc plasma reactor

    International Nuclear Information System (INIS)

    Yu Liang; Tu Xin; Li Xiaodong; Wang Yu; Chi Yong; Yan Jianhua

    2010-01-01

    In this study, four kinds of PAHs (polycyclic aromatic hydrocarbons) i.e. acenaphthene, fluorene, anthracene and pyrene are used as targets for investigation of PAHs treatment process assisted by dc gliding arc discharge. The effects of carrier gas and external resistance on the PAHs decomposition process are discussed. The results indicate that the destruction rate can be achieved to the highest with the carrier gas of oxygen and the external resistance of 50 kΩ independent of type of PAHs. Furthermore, experimental results suggest that destruction energy efficiency of gliding arc plasma would be improved by treating higher concentration pollutants. Based on the analysis of experimental results, possible destruction mechanisms in different gas discharge are discussed.

  10. Transmissive-to-black fast electrochromic switching from a long conjugated pendant group and a highly dispersed polymer/SWNT

    KAUST Repository

    Zhang, Qiang

    2018-01-03

    In this study, a novel conjugated polymer, denoted as ECPblack, is synthesized. ECPblack demonstrated a unique electrochromic behavior with an ultrahigh contrast ratio (over 80%) in most of the visible regions, boasting an ultrahigh integrated contrast ratio of 71.8% between 380 nm and 880 nm. The long conjugated pendant group (pyrene) in ECPblack enhances the absorption in the blue region in its second oxidized state and results in transmissive-to-black electrochromic switching between the neutral state and the oxidized state. The transmissive-to-black electrochromic switching polymer with an ultrahigh contrast ratio could be especially attractive for applications in electronic displays. In addition, when polytriarylamine/nanotube (SWNT/P2) dispersion is doped in ECPblack, the response time of its electrochemical and electrochromic behaviors is further reduced. The electrochromic switching and bleaching time of SWNT/P2/ECPblack decreased by 73% and 80%, respectively. The improvement is caused by the phase separation of the rigid SWNT and the flexible polymer, which generates a rough surface morphology and provides more pathways for faster diffusion of counterions (ClO4-). The polymer/SWNT doping technique provides a simple way to accelerate ion diffusion in anodically coloring materials.

  11. Transmissive-to-black fast electrochromic switching from a long conjugated pendant group and a highly dispersed polymer/SWNT

    KAUST Repository

    Zhang, Qiang; Tsai, Chou-Yi; Abidin, Taufik; Jiang, Jyh-Chiang; Shie, Wan-Ru; Li, Lain-Jong; Liaw, Der-Jang

    2018-01-01

    In this study, a novel conjugated polymer, denoted as ECPblack, is synthesized. ECPblack demonstrated a unique electrochromic behavior with an ultrahigh contrast ratio (over 80%) in most of the visible regions, boasting an ultrahigh integrated contrast ratio of 71.8% between 380 nm and 880 nm. The long conjugated pendant group (pyrene) in ECPblack enhances the absorption in the blue region in its second oxidized state and results in transmissive-to-black electrochromic switching between the neutral state and the oxidized state. The transmissive-to-black electrochromic switching polymer with an ultrahigh contrast ratio could be especially attractive for applications in electronic displays. In addition, when polytriarylamine/nanotube (SWNT/P2) dispersion is doped in ECPblack, the response time of its electrochemical and electrochromic behaviors is further reduced. The electrochromic switching and bleaching time of SWNT/P2/ECPblack decreased by 73% and 80%, respectively. The improvement is caused by the phase separation of the rigid SWNT and the flexible polymer, which generates a rough surface morphology and provides more pathways for faster diffusion of counterions (ClO4-). The polymer/SWNT doping technique provides a simple way to accelerate ion diffusion in anodically coloring materials.

  12. Novel Aflatoxin Derivatives and Protein Conjugates

    Directory of Open Access Journals (Sweden)

    Reinhard Niessner

    2007-03-01

    Full Text Available Aflatoxins, a group of structurally related mycotoxins, are well known for their toxic and carcinogenic effects in humans and animals. Aflatoxin derivatives and protein conjugates are needed for diverse analytical applications. This work describes a reliable and fast synthesis of novel aflatoxin derivatives, purification by preparative HPLC and characterisation by ESI-MS and one- and two-dimensional NMR. Novel aflatoxin bovine serum albumin conjugates were prepared and characterised by UV absorption and MALDI-MS. These aflatoxin protein conjugates are potentially interesting as immunogens for the generation of aflatoxin selective antibodies with novel specificities.

  13. Benzo[a]pyrene in urban environments of eastern Moscow: pollution levels and critical loads

    Science.gov (United States)

    Kasimov, Nikolay S.; Kosheleva, Natalia E.; Nikiforova, Elena M.; Vlasov, Dmitry V.

    2017-02-01

    Polycyclic aromatic hydrocarbons (PAHs), particularly benzo[a]pyrene (BaP), are toxic compounds emitted from various anthropogenic sources. Understanding the BaP concentrations, dynamics and decomposition in soil is required to assess the critical loads of BaP in urban environments. This study is the first attempt to evaluate all major input and output components of benzo[a]pyrene (BaP) balance and to calculate the permissible load on the urban environment in different land-use zones in the Eastern district of Moscow. BaP contamination of the snow cover in the Eastern district of Moscow was related to daily BaP fallout from the atmosphere. In 2010, the mean content of the pollutant in the snow dust was 1942 ng g-1, whereas the average intensity of its fallout was 7.13 ng m-2 per day. Across the territory, BaP winter fallout intensities varied from 0.3 to 1100 ng m-2 per day. The average BaP content in the surface (0-10 cm) soil horizons was 409 ng g-1, which is 83 times higher than the local background value and 20 times higher than the maximum permissible concentration (MPC) accepted in Russia. The variations in soil and snow BaP concentrations among different land-use zones were examined. A significant contribution of BaP from the atmosphere to urban soils was identified. Based on the measurements of BaP atmospheric fallout and BaP reserves in the soils, the critical loads of BaP for the land-use zones in the Eastern district were calculated for different values of degradation intensity and different exposure times. It was established that at an annual degradation intensity of 1-10 %, ecologically safe BaP levels in the soils of all land-use zones, excluding the agricultural zone, will only be reached after many decades or centuries.

  14. Charge-transfer excited state in pyrene-1-carboxylic acids adsorbed on titanium dioxide nanoparticles

    Science.gov (United States)

    Krawczyk, S.; Nawrocka, A.; Zdyb, A.

    2018-06-01

    The electronic structure of excited photosensitizer adsorbed at the surface of a solid is the key factor in the electron transfer processes that underlie the efficiency of dye-sensitized solar cells and photocatalysts. In this work, Stark effect (electroabsorption) spectroscopy has been used to measure the polarizability and dipole moment changes in electronic transitions of pyrene-1-carboxylic (PCA), -acetic (PAA) and -butyric (PBA) acids in ethanol, both free and adsorbed on colloidal TiO2, in glassy ethanol at low temperature. The lack of appreciable increase of dipole moment in the excited state of free and adsorbed PAA and PBA points that two or more single bonds completely prevent the expansion of π-electrons from the aromatic ring towards the carboxylic group, thus excluding the possibility of direct electron injection into TiO2. In free PCA, the pyrene's forbidden S0 → S1 transition has increased intensity, exhibits a long progression in 1400 cm-1 Ag mode and is associated with |Δμ| of 2 D. Adsorption of PCA on TiO2 causes a broadening and red shift of the S0 → S1 absorption band and an increase in dipole moment change on electronic excitation to |Δμ| = 6.5 D. This value increased further to about 15 D when the content of acetic acid in the colloid was changed from 0.2% to 2%, and this effect is ascribed to the surface electric field. The large increase of |Δμ| points that the electric field effect can not only change the energetics of electron transfer from the excited sensitizer into the solid, but can also shift the molecular electronic density, thus directly influencing the electronic coupling factor relevant for electron transfer at the molecule-solid interface.

  15. Hydrodynamic and Thermophoretic Effects on the Supramolecular Chirality of Pyrene-Derived Nanosheets.

    Science.gov (United States)

    Micali, Norberto; Vybornyi, Mykhailo; Mineo, Placido; Khorev, Oleg; Häner, Robert; Villari, Valentina

    2015-06-22

    Chiroptical properties of two-dimensional (2D) supramolecular assemblies (nanosheets) of achiral, charged pyrene trimers (Py3 ) are rendered chiral by asymmetric physical perturbations. Chiral stimuli in a cuvette can originate either from controlled temperature gradients or by very gentle stirring. The chiroptical activity strongly depends on the degree of supramolecular order of the nanosheets, which is easily controlled by the method of preparation. The high degree of structural order ensures strong cooperative effects within the aggregates, rendering them more susceptible to external stimuli. The samples prepared by using slow thermal annealing protocols are both CD and LD active (in stagnant and stirred solutions), whereas for isothermally aged samples chiroptical activity was in all cases undetectable. In the case of temperature gradients, the optical activity of 2D assemblies could be recorded for a stagnant solution due to migration of the aggregates from the hottest to the coldest regions of the system. However, a considerably stronger exciton coupling, coinciding with the J-band of the interacting pyrenes, is developed upon subtle vortexing (0.5 Hz, 30 rpm) of the aqueous solution of the nanosheets. The sign of the exciton coupling is inverted upon switching between clockwise and counter-clockwise rotation. The supramolecular chirality is evidenced by the appearance of CD activity. To exclude artefacts from proper CD spectra, the contribution from LD to the observed CD was determined. The data suggest that the aggregates experience asymmetrical deformation and alignment effects because of the presence of chiral flows. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Development of Tat-Conjugated Dendrimer for Transdermal DNA Vaccine Delivery.

    Science.gov (United States)

    Bahadoran, Azadeh; Moeini, Hassan; Bejo, Mohd Hair; Hussein, Mohd Zobir; Omar, Abdul Rahman

    In order to enhance cellular uptake and to facilitate transdermal delivery of DNA vaccine, polyamidoamine (PAMAM) dendrimers conjugated with HIV transactivator of transcription (TAT) was developed. First, the plasmid DNA (pIRES-H5/GFP) nanoparticle was formulated using PAMAM dendrimer and TAT peptide and then characterized for surface charge, particle size, DNA encapsulation and protection of the pIRES-H5/GFP DNA plasmid to enzymatic digestion. Subsequently, the potency of the TAT-conjugated dendrimer for gene delivery was evaluated through in vitro transfection into Vero cells followed by gene expression analysis including western blotting, fluorescent microscopy and PCR. The effect of the TAT peptide on cellular uptake of DNA vaccine was studied by qRT-PCR and flow cytometry. Finally, the ability of TAT-conjugated PAMAM dendrimer for transdermal delivery of the DNA plasmid was assessed through artificial membranes followed by qRT-PCR and flow cytometry. TAT-conjugated PAMAM dendrimer showed the ability to form a compact and nanometre-sized polyplexes with the plasmid DNA, having the size range of 105 to 115 nm and a positive charge of +42 to +45 mV over the N/P ratio of 6:1(+/-).  In vitro transfection analysis into Vero cells confirms the high potency of TAT-conjugated PAMAM dendrimer to enhance the cellular uptake of DNA vaccine.  The permeability value assay through artificial membranes reveals that TAT-conjugated PAMAM has more capacity for transdermal delivery of the DNA compared to unmodified PAMAM dendrimer (Pdendrimer is a promising non-viral vector for transdermal use.This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

  17. Random Forest Approach to QSPR Study of Fluorescence Properties Combining Quantum Chemical Descriptors and Solvent Conditions.

    Science.gov (United States)

    Chen, Chia-Hsiu; Tanaka, Kenichi; Funatsu, Kimito

    2018-04-22

    The Quantitative Structure - Property Relationship (QSPR) approach was performed to study the fluorescence absorption wavelengths and emission wavelengths of 413 fluorescent dyes in different solvent conditions. The dyes included the chromophore derivatives of cyanine, xanthene, coumarin, pyrene, naphthalene, anthracene and etc., with the wavelength ranging from 250 nm to 800 nm. An ensemble method, random forest (RF), was employed to construct nonlinear prediction models compared with the results of linear partial least squares and nonlinear support vector machine regression models. Quantum chemical descriptors derived from density functional theory method and solvent information were also used by constructing models. The best prediction results were obtained from RF model, with the squared correlation coefficients [Formula: see text] of 0.940 and 0.905 for λ abs and λ em , respectively. The descriptors used in the models were discussed in detail in this report by comparing the feature importance of RF.

  18. Synthesis and bio-applications of targeted magnetic-fluorescent composite nanoparticles

    International Nuclear Information System (INIS)

    Xia, Hui; Tong, Ruijie; Song, Yanling; Xiong, Fang; Li, Jiman; Wang, Shichao; Fu, Huihui; Wen, Jirui; Li, Dongze; Zeng, Ye; Zhao, Zhiwei; Wu, Jiang

    2017-01-01

    Magnetic-fluorescent nanoparticles have a tremendous potential in biology. As the benefits of these materials gained recognition, increasing attention has been given to the conjugation of magnetic-fluorescent nanoparticles with targeting ligands. The magnetic and fluorescent properties of nanoparticles offer several functionalities, including imaging, separation, and visualization, while the presence of a targeting ligand allows for selective cell and tissue targeting. In this review, methods for the synthesis of targeted magnetic-fluorescent nanoparticles are explored, and recent applications of these nanocomposites to the detection and separation of biomolecules, fluorescent and magnetic resonance imaging, and cancer diagnosis and treatment will be summarized. As these materials are further optimized, targeted magnetic-fluorescent nanoparticles hold great promise for the diagnosis and treatment of some diseases.

  19. Synthesis and bio-applications of targeted magnetic-fluorescent composite nanoparticles

    Science.gov (United States)

    Xia, Hui; Tong, Ruijie; Song, Yanling; Xiong, Fang; Li, Jiman; Wang, Shichao; Fu, Huihui; Wen, Jirui; Li, Dongze; Zeng, Ye; Zhao, Zhiwei; Wu, Jiang

    2017-04-01

    Magnetic-fluorescent nanoparticles have a tremendous potential in biology. As the benefits of these materials gained recognition, increasing attention has been given to the conjugation of magnetic-fluorescent nanoparticles with targeting ligands. The magnetic and fluorescent properties of nanoparticles offer several functionalities, including imaging, separation, and visualization, while the presence of a targeting ligand allows for selective cell and tissue targeting. In this review, methods for the synthesis of targeted magnetic-fluorescent nanoparticles are explored, and recent applications of these nanocomposites to the detection and separation of biomolecules, fluorescent and magnetic resonance imaging, and cancer diagnosis and treatment will be summarized. As these materials are further optimized, targeted magnetic-fluorescent nanoparticles hold great promise for the diagnosis and treatment of some diseases.

  20. Synthesis and bio-applications of targeted magnetic-fluorescent composite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Hui; Tong, Ruijie [Sichuan University, West China Medical Center (China); Song, Yanling [Shenyang University of Chemical Technology, College of Pharmaceutical and Biological Engineering (China); Xiong, Fang [Sichuan University, West China College of Stomatology (China); Li, Jiman [Sichuan Cancer Hospital, Pathology Department (China); Wang, Shichao; Fu, Huihui; Wen, Jirui; Li, Dongze; Zeng, Ye; Zhao, Zhiwei, E-mail: zzw2002400@126.com; Wu, Jiang, E-mail: jw@scu.edu.cn [Sichuan University, West China Medical Center (China)

    2017-04-15

    Magnetic-fluorescent nanoparticles have a tremendous potential in biology. As the benefits of these materials gained recognition, increasing attention has been given to the conjugation of magnetic-fluorescent nanoparticles with targeting ligands. The magnetic and fluorescent properties of nanoparticles offer several functionalities, including imaging, separation, and visualization, while the presence of a targeting ligand allows for selective cell and tissue targeting. In this review, methods for the synthesis of targeted magnetic-fluorescent nanoparticles are explored, and recent applications of these nanocomposites to the detection and separation of biomolecules, fluorescent and magnetic resonance imaging, and cancer diagnosis and treatment will be summarized. As these materials are further optimized, targeted magnetic-fluorescent nanoparticles hold great promise for the diagnosis and treatment of some diseases.