- Osmium bipyridine-containing redox polymers based on cellulose and their reversible redox activity
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Thermo-, pH-, and electrochemical-sensitive cellulose graft copolymers, hydroxypropyl cellulose-g-poly(4-vinylpyridine)-Os(bipyridine) (HPC-g-P4VP-Os(bpy)), were synthesized and characterized. The electrochemical properties of the resulting material were investigated via cyclic voltammetry by coating the graft copolymers on the platinized carbon electrode. The results indicated that the electrochemical properties of the graft copolymer modified electrode were responsive to the pH values of the electrolyte solution. The reversible transformation between the active and inactive state originated from the changes in the architecture of the HPC-g-P4VP-Os(bpy) graft copolymer at different pH values. At high pH (e.g., above the pKa of P4VP), the chains of P4VP collapsed, and the electrochemical activity of the electrode was reduced. With immobilization of glucose oxidase (GOx) on the graft copolymer decorated electrode, a biosensor for glucose detection was prepared. The current of the biosensor depended on the glucose concentration in the detected solution and increased with the successive addition of glucose.
- Kang, Hongliang,Liu, Ruigang,Sun, Huafeng,Zhen, Jieming,Li, Qinmei,Huang, Yong
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- A NIR phosphorescent osmium(ii) complex as a lysosome tracking reagent and photodynamic therapeutic agent
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A novel near infrared (NIR) phosphorescent osmium complex (Os1) was developed for lysosome tracking and photodynamic therapy. Owing to its NIR photophysical properties, cellular imaging ability and phototoxicity, it has advantages over its ruthenium analogue (Ru1).
- Zhang, Pingyu,Wang, Yi,Qiu, Kangqiang,Zhao, Zhiqian,Hu, Rentao,He, Chuanxin,Zhang, Qianling,Chao, Hui
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- ELECTROCHEMILUMINESCENCE OF OSMIUM COMPLEXES. SPECTRAL, ELECTROCHEMICAL, AND MECHANISTIC STUDIES.
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This study presents further electrochemical and electrochemiluminescent characterization of phenanthroline and bipyridine complexes of osmium. It is found that a large number of these complexes will give rise to ECL emission, although, in some cases, the observed ECL intensity was much lower than had been anticipated. It is also demonstrated that surface ECL can also be observed from the films of electropolymerized complexes. Though the emission arising from these films is not as intense as that observed from electropolymerized Ru(vinyl-bipyridine)//3**2** plus films, it is much longer lived.
- Abruna
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- Osmium(II) polypyridyl polyarginine conjugate as a probe for live cell imaging; A comparison of uptake, localization and cytotoxicity with its ruthenium(II) analogue
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A first investigation into the application of a luminescent osmium(II) bipyridine complex to live cell imaging is presented. Osmium(II) (bis-2,2-bipyridyl)-2(4-carboxylphenyl) imidazo[4,5f][1,10]phenanthroline was prepared and conjugated to octaarginine, a cell penetrating peptide. The photophysics, cell uptake and cytotoxicity of this osmium complex conjugate were performed and compared with its ruthenium analogue. Cell uptake and distribution of both ruthenium and osmium conjugates were very similar with rapid transmembrane transport of the osmium probe (complete within approx. 20 min) and dispersion throughout the cytoplasm and organelles. The near-infrared (NIR) emission of the osmium complex (λmax 726 nm) coincides well with the biological optical window and this facilitated luminescent and luminescence lifetime imaging of the cell which was well resolved from cell autofluorescence. The large Stokes shift of the emission also permitted resonance Raman mapping of the dye within CHO cells. Rather surprisingly, the osmium conjugate exhibited very low cytotoxicity when incubated both in the dark and under visible irradiation. This was attributed to the remarkable stability of this complex which was reflected by the complete absence of photo-bleaching of the complex even under extended continuous irradiation. In addition, when compared to its ruthenium analogue its luminescence was short-lived in water therefore rendering it insensitive to O2.
- Byrne, Aisling,Dolan, Ciarn,Moriarty, Roisin D.,Martin, Aaron,Neugebauer, Ute,Forster, Robert J.,Davies, Anthony,Volkov, Yuri,Keyes, Tia E.
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- Measurement of the free-energy dependence of interfacial charge-transfer rate constants using ZnO/H2O semiconductor/liquid contacts
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The dependence of electron-transfer rate constants on the driving force for interfacial charge transfer has been investigated using n-type ZnO electrodes in aqueous solutions. Differential capacitance versus potential and current density versus potential measurements were used to determine the energetics and kinetics, respectively, of the interfacial electron-transfer processes. A series of nonadsorbing, one-electron, outer-sphere redox couples with formal reduction potentials that spanned approximately 900 mV allowed evaluation of both the normal and Marcus inverted regions of interfacial electron-transfer processes. All rate processes were observed to be kinetically first-order in the concentration of surface electrons and first-order in the concentration of dissolved redox acceptors. The band-edge positions of the ZnO were essentially independent of the Nernstian potential of the solution over the range 0.106-1.001 V vs SCE. The rate constant at optimal exoergicity was observed to be approximately 10-16 cm4 s-1. The rate constant versus driving force dependence at n-type ZnO electrodes exhibited both normal and inverted regions, and the data were well-fit by a parabola generated using classical Marcus theory with a reorganization energy of 0.67 eV. NMR line broadening measurements of the self-exchange rate constants indicated that the redox couples had reorganization energies of 0.64-0.69 eV. The agreement between the reorganization energy of the ions in solution and the reorganization energy for the interfacial electron-transfer processes indicated that the reorganization energy was dominated by the redox species in the electrolyte, as expected from an application of Marcus theory to semiconductor electrodes.
- Hamann, Thomas W.,Gstrein, Florian,Brunschwig, Bruce S.,Lewis, Nathan S.
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- Water-Soluble Osmium Complexes Suitable for use in Luminescence-Based, Hydrogel-Supported Sensors
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Osmium transition metal complexes are of particular interest in luminescence-based sensing applications because of their longer wavelength absorptions and emissions, relative to similar ruthenium and rhenium complexes, that allow for inexpensive excitation and minimize interferences from autofluorescence when the sensor is used in biological samples. Reported here are the photophysical properties of a series of water-soluble osmium complexes suitable for use in hydrogel-based sensors: [Os(bpy)2(sulf-dpp)]Cl2, [Os(phen)2(sulf-dpp)]Cl2, [Os(dpp)2(sulf-dpp)]Cl2, and [Os(CO)2Cl2(sulf-dpp)], where bpy is 2,2′-bipyridine, phen is 1,10-phenanthroline, dpp is 4,7-diphenyl-1,10-phenanthroline, and sulf-dpp is bathophenanthrolinedisulfonic acid disodium salt. The family of complexes showed minimal oxygen quenching, making them particularly well-suited for sensing applications in which oxygen concentration varies. Luminescence anisotropy was found to depend more significantly on net dipole moment than hydrodynamic radius of the molecule, and, as expected, excited state lifetime and luminescence anisotropy were highly dependent on the local environment of the reporter molecule. Results obtained for hydrogel-based relative humidity sensors containing [Os(CO)2Cl2(sulf-dpp)] and [Os(bpy)2(sulf-dpp)]Cl2 complexes highlight the significant potential for this class of compounds in a hydrogel-supported luminescence-based sensing approach.
- Wagner, Amy M.,Strohecker, Sarah A.,Costello, Elizabeth K.,Rood, Jeffrey A.,Kneas, Kristi A.
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- Sensor array system for discrimination and detection for reactive chemical species comprising fluorescence compounds
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The present invention relates to a sensor array system comprising a fluorescent compound for discrimination and detection of active species. 2 Or more compounds according to one aspect, hydrates, solvates or salts thereof, compositions for detecting active species including the same, sensor arrays, or methods of detecting active species using the same are capable of selectively distinguishing various active species. The present invention relates to a composition for detecting an active species, a method for detecting an active species, and a method for detecting an active species.
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Paragraph 0127-0130
(2021/06/15)
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- Physical, spectroscopic, and biological properties of ruthenium and osmium photosensitizers bearing diversely substituted 4,4′-di(styryl)-2,2′-bipyridine ligands
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Capitalising on the previous identification of a distyryl coordinated Ru(ii) polypyridine complex as a promising photosensitizer for photodynamic therapy, eight new complexes were synthesized by modifications of the ligands or by changing the metal coordinated. We report in this work the effects of these modifications on the physical, spectroscopic, and biological properties of the synthesized complexes. Subtle structural modifications of the distyryl ligand only had a moderate effect on the corresponding complexes' visible light absorption and singlet oxygen quantum yield. These modifications however had a significant effect on the lipophilicity, the cellular uptake and the phototoxicity of the complexes. Although the lipophilicity of the complexes had a somewhat expected effect on their cellular uptake, this last parameter could not be directly correlated to their phototoxicity, revealing other underlying phenomena. Overall, this work allowed identification of two promising ruthenium complexes as photosensitisers for photodynamic therapy and provides some guidance on how to design better photosensitizers. This journal is
- Cariou, Kevin,Gasser, Gilles,Karges, Johannes,Tharaud, Micka?l,Vinck, Robin
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p. 14629 - 14639
(2021/11/03)
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- Osmium complex as well as preparation method and application thereof
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The invention relates to an osmium complex as well as a preparation method and application thereof. The method comprises the following steps: adding ammonium chlorosmate and dipyridine into an organicsolvent, and performing a reaction so as to obtain a mixed solution; adding a reducing agent into the mixed solution, and performing a reaction so as to obtain an osmium complex precursor; and addingthe osmium complex precursor and 5-chlorine-2-benzodiazopyridine into ethylene glycol according to a preset ratio, performing a reaction under predetermined reaction conditions, and adding target anion, so as to obtain the osmium complex. The osmium complex provided by the invention has extremely high structural stability, barely emits fluorescence, has strong cytotoxicity to tumor cells, has selectivity to cancer cells, and can be applied in the field of Raman imaging of tumor cells.
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Paragraph 0026; 0048; 0049
(2020/02/19)
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- One type of dual-wavelength emission, double-heteronuclear metal complex and its preparation method and application
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The invention provides a double-wavelength emitting heterobinuclear metal complex as well as a preparation method and application thereof. The heterobinuclear metal complex has the structural general formula: (L1L2)M-L3-M'(L4L5)Ym, wherein M and M' are respectively and independently selected from Ru, Os, Ir and Re, but, M and M' cannot be the same metal at the same time. The heterobinuclear metal complex can be used as an electrogenerated chemiluminescent substance, and the heterobinuclear metal complex or the heterobinuclear metal complex and amines are used as a co-reactant, so that single-wavelength ECL detection can be realized under respective emitting wavelengths, and proportional ECL detection can also be realized under double emitting wavelengths. Particularly, when one of M and M' is Ir, the heterobinuclear metal complex can only be used for specifically dyeing RNA (Ribonucleic Acid), and the heterobinuclear metal complex is remarkably enhanced in fluorescence after being dyed and can be used for RNA nature determination, quantitative detection and relevant fields such as nucleic acid marking, clinic medical diagnosis, blood cell analysis, immunoassay detection and cancer therapy.
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Paragraph 0147; 0148
(2017/05/23)
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- Toward the Control of the Creation of Mixed Monolayers on Glassy Carbon Surfaces by Amine Oxidation
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A versatile and simple methodology for the creation of mixed monolayers on glassy carbon (GC) surfaces was developed, using an osmium-bipyridyl complex and anthraquinone as model redox probes. The work consisted in the electrochemical grafting on GC of a mixture of mono-protected diamine linkers in varying ratios which, after attachment to the surface, allowed orthogonal deprotection. After optimisation of the deprotection conditions, it was possible to remove one of the protecting groups selectively, couple a suitable osmium complex and cap the residual free amines. The removal of the second protecting group allowed the coupling of anthraquinone. The characterisation of the resulting surfaces by cyclic voltammetry showed the variation of the surface coverage of the two redox centres in relation to the initial ratio of the linking amine in solution.
- Groppi, Jessica,Bartlett, Philip N.,Kilburn, Jeremy D.
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supporting information
p. 1030 - 1036
(2016/01/16)
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- Preparation of fluorescent tubulin binders
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Thiocolchicine, taxol and cephalomannine have been used as building blocks for the preparation of four different fluorescent compounds designed to image the tubulin/microtubule network in cells. Thiocolchicine gave the best results and, in particular, the compound derived from conjugation with fluorescein minimally inhibits tubulin polymerization, is cell permeable and binds microtubules. Thus, it meets some of the demanding requirements for a new fluorescent dye that can secure a direct assay to evidence the tubulin/microtubules network in cells.
- Riva, Elena,Mattarella, Martin,Borrelli, Stella,Christodoulou, Michael S.,Cartelli, Daniele,Main, Marcus,Faulkner, Stephen,Sykes, Daniel,Cappelletti, Graziella,Snaith, John S.,Passarella, Daniele
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p. 222 - 226
(2013/06/04)
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- A structurally diverse mixed-metal complex with mixed bridging ligands [{[(bpy)2Os(dpp)]2Ru}2(dpq)](PF6)12: Modulating orbital energetics within a supramolecular architecture
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A structurally diverse supramolecular complex, [{[(bpy)2Os(dpp)]2Ru}2(dpq)](PF6)12, has been prepared (bpy = 2,2′-bipyridine, dpp = 2,3-bis(2-pyridyl)pyrazine, and dpq = 2,3-bis(2-pyridyl)quinoxaline). The supramolecular assembly contains four light absorbing osmium metal centers coupled to two ruthenium metal centers linked by two different bridging ligands (BL) capped by bpy terminal ligands. This supramolecule possesses a lowest unoccupied molecular orbital (LUMO) localized on the central μ-dpq bridging ligand (BL) and a highest occupied molecular orbital (HOMO) localized on the terminal Os centers, providing significant spatial separation of these donor and acceptor orbitals. This hexametallic complex absorbs throughout the visible region due to overlapping singlet metal-to-ligand charge transfer (MLCT) transitions from the Os and Ru chromophores to each π-acceptor ligand. The Os based 3MLCT bands extend into the near-infrared. The light absorbing and redox properties for this hexametallic complex have been elucidated using smaller model fragments and spectroelectrochemistry.
- Miao, Ran,Brewer, Karen J.
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p. 307 - 312
(2008/10/09)
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- BINUCLEAR METAL COMPLEX, METAL COMPLEX DYE, PHOTOELECTRIC TRANSDUCER AND PHOTOCHEMICAL BATTERY
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A novel binuclear metal complex according to the present invention is an asymmetric binuclear metal complex represented by the general formula: (L1)2M1(BL)M2(L2)2(X)n, wherein M1 and M2, which may be identical or different, represent a transition metal; L1 and L2, which are different, represent a chelate ligand capable of polydentate coordination and two L1s may be different and two L2s may be different; BL represents a bridge ligand having at least two heteroatom-containing cyclic structures, the heteroatoms contained in the cyclic structures being ligand atoms coordinating to M1 and M2; X represents a counter ion; and n is the number of counter ions needed to neutralize the charge of the complex. And the binuclear metal complex is useful as a metal complex dye.
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Page/Page column 32
(2008/06/13)
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- Toward exceeding the Shockley-Queisser limit: Photoinduced interfacial charge transfer processes that store energy in excess of the equilibrated excited state
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Nanocrystalline (anatase), mesoporous TiO2 thin films were functionalized with [Ru(bpy)2(deebq)]-(PF6)2, [Ru(bq)2(deeb)](PF6)2, [Ru(deebq) 2(bpy)](PF6)2, [Ru(bpy)(deebq)(NCS) 2], or [Os(bpy)2(deebq)](PF6)2, where bpy is 2,2′-bipyridine, bq is 2,2′-biquinoline, and deeb and deebq are 4,4′-diethylester derivatives. These compounds bind to the nanocrystalline TiO2 films in their carboxylate forms with limiting surface coverages of 8 (± 2) × 10-8 mol/cm2. Electrochemical measurements show that the first reduction of these compounds (-0.70 V vs SCE) occurs prior to TiO2 reduction. Steady state illumination in the presence of the sacrificial electron donor triethylamine leads to the appearance of the reduced sensitizer. The thermally equilibrated metal-to-ligand charge-transfer excited state and the reduced form of these compounds do not inject electrons into TiO2. Nanosecond transient absorption measurements demonstrate the formation of an extremely long-lived charge separated state based on equal concentrations of the reduced and oxidized compounds. The results are consistent with a mechanism of ultrafast excited-state injection into TiO2 followed by interfacial electron transfer to a ground-state compound. The quantum yield for this process was found to increase with excitation energy, a behavior attributed to stronger overlap between the excited sensitizer and the semiconductor acceptor states. For example, the quantum yields for [Os(bpy)2(dcbq)]/TiO2 were φ(417 nm) = 0.18 ± 0.02, φ(532.5 nm) = 0.08 ± 0.02, and φ(683 nm) = 0.05 ± 0.01. Electron transfer to yield ground-state products occurs by lateral intermolecular charge transfer. The driving force for charge recombination was in excess of that stored in the photoluminescent excited state. Chronoabsorption measurements indicate that ligand-based intermolecular electron transfer was an order of magnitude faster than metal-centered intermolecular hole transfer. Charge recombination was quantified with the Kohlrausch-Williams-Watts model.
- Hoertz, Paul G.,Staniszewski, Aaron,Marton, Andras,Higgins, Gerard T.,Incarvito, Christopher D.,Rheingold, Arnold L.,Meyer, Gerald J.
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p. 8234 - 8245
(2007/10/03)
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- ELECTROCHEMICAL AFFINITY BIOSENSOR SYSTEM AND METHODS
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The present invention provides novel osmium-based electrochemical species for the detection of wide variety of analytes using immunological techniques. The present invention also provides diagnostic kits and test sensors supporting electrode structures that can be used with the osmium-based electrochemical species. The test sensor can be fabricated to support interdigitated arrays of electrodes that have been designed to provide amplification of the electrical signal amplification desired to analyze analytes that may be present at low concentrations.
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Page/Page column 50; 51; 65
(2010/02/11)
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