20 research outputs found
SYNTHESIS OF Au-NANOPARTICLES USING GOLD RECOVERED FROM ELECTRONIC WASTE
This work was supported by the Araucária Foundation, a Research Founding Agency from Paraná State – Brazil, CAPES and CNPq
MATERIALS FOR SENSOR DEVICES: FROM PHARMACEUTICAL QUANTIFICATION TO DISEASES DIAGNOSIS
This work was supported by the Paraná State Research Funding Agency (Araucária Foundation – project # FA-SESA 073/2016 - CP 04/2016) and by the Federal Agencies CAPES and CNPq (project # CNPq PVE 401271/2014-5)
GOLD-NANOPARTICLES THIN FILMS AS PLATAFORM FOR LABEL-FREE IMPEDIMETRIC IMMUNOSENSOR FOR DETECTION OF T. CRUZI ANTIBODIES
This work was supported by the Araucária Foundation, a Research Founding Agency from Paraná State – Brazil, CAPES and CNPq
Synthesis and Characterization of a Naphthalimide-Benzonitrile Derivative and Evaluation of Optoelectronics Properties
The authors would like to thank the Brazilian Agency Funding: CNPq, CAPES and Fundaçăo Araucária
Interaction between active ruthenium complex [RuCl3(dppb)(VPy)] and phospholipid Langmuir monolayers: Effects on membrane electrical properties
We report on the interaction between mer-[RuCl3(dppb)(VPy)] (dppb = 1,4-bis(diphenylphosphine)-butane and VPy=4-vinylpyridine) (RuVPy) and dipalmitoyl phosphatidyl serine (DPPS), in Langmuir and Langmuir-Blodgett (LB) films. Interaction of RuVPy with DPPS, which predominates in cancer cell membranes, should be weaker than for other phospholipids since RuVPy is less toxic to cancer cells than to healthy cells. Incorporation of RuVPy induced smaller changes in electrochemical properties of LB films of DPPS than for other phospholipids, but the same did not apply to surface pressure isotherms. This calls for caution in establishing correlations between effects from a single property and phenomena on cell membranes. (C) 2014 Elsevier B.V. All rights reserved.FAPESP (Brazil)CNPq (Brazil)CAPES (Brazil)nBioNet (Brazil)Univ Estadual Ponta Grossa, Appl Chem Program, BR-84035900 Ponta Grossa, PR, BrazilUniv Sao Paulo, Sao Carlos Inst Phys, BR-13560970 Sao Carlos, SP, BrazilUniv Fed Sao Paulo, Dept Exact Sci, BR-09972270 Diadema, SP, BrazilUniv Fed Sao Paulo, Dept Exact Sci, BR-09972270 Diadema, SP, BrazilWeb of Scienc
Effects of chlorine gas exposure on the optical properties of rhodium phthalocyanine films
We investigated the effects of exposing rhodium phthalocyanine films deposited on glass substrates by the Lagmuir-Blodgett technique to chlorine gas. The visual aspect of the films is altered upon chlorination, changing in color from blue to transparent. We performed optical absorption and Raman Scattering measurements on our films prior to and after exposing it to chlorine gas. We observed a pronounced quenching of the characteristic triplet centered around the Q-absorption band at 662 nm as a result of chlorine incorporation. Another absorption band, in the near UV part of the spectrum, is not greatly affected by the process. No new optical structures appear as a consequence of chlorination. Equivalent effects were observed in the Raman spectra. Leaving the previously exposed films in air for several hours results in a slow partial recovery of the optical spectra. This recovery, as well as the amount of original quenching, depends on the amount of time during which the film was exposed to chlorine. (C) 2004 Elsevier Ltd. All rights reserved.1311535
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Langmuir and Langmuir-Blodgett films containing a porphyrin-ruthenium complex
The fabrication of supramolecular structures from the tetraruthenated porphyrin-containing phosphines, {TPyP[RuCl3(dppb)](4)}, RuTPyP, is demonstrated with Langmuir and Langmuir-Blodgett films. The surface pressure-molecular area isotherms (pi-A) point to an edge-on arrangement for the RuTPyP molecules in the condensed state. Weak aggregation in the Langmuir films was indicated by non-zero surface potentials at large areas per molecule and a slight red shift in the ultraviolet-visible absorption spectrum in comparison to the spectrum in solution. Further aggregation occurs in the Z-type Lang muir-Blodgett films, which was confirmed with ultraviolet-visible spectroscopy of the deposited films. Fourier transform infrared and Raman spectroscopic data for powder and Langmuir-Blodgett films indicate that the RuTPyP molecules are chemically stable in Langmuir-Blodgett films regardless of the contact with water during film fabrication. The nanostructured nature of the Langmuir-Blodgett films was manifested in cyclic voltammetry due to the high sensitivity of the metallic centers in RuTPyR Electrodes modified with Langmuir-Blodgett films exhibit an anodic peak at 100 mV and a cathodic peak at 7 mV, which is assigned to RuIII/RuII redox processes. Furthermore, Langmuir-Blodgett films from RuTPyP showed electrocatalytic activity for oxidation of benzyl alcohol, illustrated by a large shift of 100 mV in the anodic peak at 400 mV, while electropolymerized and cast films of the same compound displayed smaller and no activities, respectively
Preparation, characterization and taste sensing properties of Langmuir-Blodgett Films from mixtures of polyaniline and a ruthenium complex
Langmuir-Blodgett (LB) films from a ruthenium complex, mer-[RuCl3(dppb)(py)] (dppb = PPh2(CH2)(4)PPh2; py = pyridine) (Rupy), and from mixtures with varied amounts of polyaniline (PANi) were fabricated. Molecular-level interactions between the two components are investigated by surface potential, dc conductivity and Raman spectroscopy measurements, particularly for the mixed film with 10% of Rupy. For the latter, the better miscibility led to an interaction with Rupy inducing a decrease in the conducting state of PANi, as observed in the Raman spectra and conductivity measurement. The interaction causes the final film properties to depend on the concentration of Rupy, and this was exploited to produce a sensor array made up of sensing units consisting of 11-layer LB films from pure PANi, pure Rupy and mixtures with 10 and 30% of Rupy. It is shown that the combination of only four non-specific sensing units allows one to distinguish the basic tastes detected by biological systems, viz. saltiness, sweetness, sourness and bitterness, at the muM level. (C) 2003 Elsevier B.V. Ltd. All rights reserved
Electrosynthesis of binuclear ruthenium complexes from [RuCl3(dppb)(L)] precursors [L = pyridine, 4-methylpyridine or dimethyl sulfoxide; dppb=1,4-bis(diphenylphosphino)butane]
Electrolysis has been examined as a method of synthesis for [(L)(dppb)Ru(mu-Cl)(3)RuCl(dppb)] complexes, where dppb = 1,4-bis(diphenylphosphino)butane and L = pyridine (py), 4-methylpyridine (4-pic) or dimethyl sulfoxide (DMSO), by using [RuCl3(dppb)(L)] as precursors. The products of the electrolysis were characterized by P-31-{H-1} NMR, cyclic voltammetry and near infrared spectroscopy. The presence of the [Ru2Cl5(dppb)(2)] complex in the electrochemical cell suggests a mechanism by which the starting original species from the bulk solution reacts with the reduced form [RuCl2(dppb)(L)] generated at the surface of the electrode. The crystal structure of the precursor mer-[RuCl3(dppb)(4-pic)] was determined by X-ray diffraction