65 research outputs found

    Characterization of electrodeposited zinc oxide/tetrasulphonatedcopper phthalocyanines (ZnO/Ts-CuPc) hybrid films and their photoelectrochemical properties

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    a b s t r a c t Hybrid films of zinc oxide (ZnO) and tetrasulphonatedcopper phthalocyanine (Ts-CuPc) have been prepared by cathodic electro-deposition from aqueous O 2 -saturated solutions of ZnCl 2 and Ts-CuPc. The Ts-CuPc content of the films can be varied in a wide range by variation of dye concentration in the electro-deposition bath -from single Ts-CuPc molecules embedded in compact crystalline ZnO to films based on an amorphous Ts-CuPc framework. With increasing dye content the colour of the films changes from light blue to deep blue. All films were characterized by XRD, SEM and AFM. Photoelectro-chemical characteristics of the electrodes were studied by photocurrent spectra and by time-resolved photocurrent measurements in 0.1 M KCl electrolyte. At the same time, changes in the electrical and photoelectrical properties of the films are observed, enabling the tuning of these properties in view of optoelectronic applications. Theoretical calculations based on density functional theory (DFT) models were made to understand the optoelectronic properties of the hybrid films. Different parallel and perpendicular orientations were tested. For the most stable hybrid structure, total and projected densities of states of the system were obtained and the alignment of the levels observed

    Structural, Vibrational, and Electronic Study of α‑As2Te3 under Compression

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    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/acs.jpcc.6b06049We report a study of the structural, vibrational, and electronic properties of layered monoclinic arsenic telluride (α-As2Te3) at high pressures. Powder X-ray diffraction and Raman scattering measurements up to 17 GPa have been complemented with ab initio total-energy, lattice dynamics, and electronic band structure calculations. Our measurements, which include previously unreported Raman scattering measurements for crystalline α-As2Te3, show that this compound undergoes a reversible phase transition above 14 GPa at room temperature. The monoclinic crystalline structure of α-As2Te3 and its behavior under compression are analyzed by means of the compressibility tensor. Major structural and vibrational changes are observed in the range between 2 and 4 GPa and can be ascribed to the strengthening of interlayer bonds. No evidence of any isostructural phase transition has been observed in α-As2Te3. A comparison with other group 15 sesquichalcogenides allows understanding the structure of α-As2Te3 and its behavior under compression based on the activity of the cation lone electron pair in these compounds. Finally, our electronic band structure calculations show that α-As2Te3 is a semiconductor at 1 atm, which undergoes a trivial semiconducting−metal transition above 4 GPa. The absence of a pressure-induced electronic topological transition in α-As2Te3 is discussed.This work has been performed under financial support from Projects MAT2013-46649-C4-2-P, MAT2013-46649-C4-3-P, MAT2015-71070-REDC, FIS2013-48286-C2-1-P, and FIS2013-48286-C2-2-P of the Spanish Ministry of Economy and Competitiveness (MINECO), and the Department of Education, Universities and Research of the Basque Government and UPV/EHU (Grant No. IT756-13). This publication is also fruit of "Programa de Valoracion y Recursos Conjuntos de I+D+i VLC/CAMPUS" and has been financed by the Spanish Ministerio de Educacion, Cultura y Deporte as part of "Programa Campus de Excelencia Internacional" through Projects SP20140701 and SP20140871. Finally, authors thank ALBA Light Source for beam allocation at beamline MSPD.Cuenca Gotor, VP.; Sans-Tresserras, JÁ.; Ibáñez, J.; Popescu, C.; Gomis, O.; Vilaplana Cerda, RI.; Manjón Herrera, FJ.... (2016). Structural, Vibrational, and Electronic Study of α‑As2Te3 under Compression. Journal of Physical Chemistry C. 120(34):19340-19352. https://doi.org/10.1021/acs.jpcc.6b06049S19340193521203

    A surface plasmon resonance based approach for measuring response to pneumococcal vaccine

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    Incidence of pneumococcal disease has increased worldwide in recent years. Response to pneumococcal vaccine is usually measured using the multiserotype enzyme-linked immunosorbent assay (ELISA) pneumococcal test. However, this approach presents several limitations. Therefore, the introduction of new and more robust analytical approaches able to provide information on the efficacy of the pneumococcal vaccine would be very beneficial for the clinical management of patients. Surface plasmon resonance (SPR) has been shown to offer a valuable understanding of vaccines' properties over the last years. The aim of this study is to evaluate the reliability of SPR for the anti-pneumococcal capsular polysaccharides (anti-PnPs) IgGs quantification in vaccinated. Fast protein liquid chromatography (FPLC) was used for the isolation of total IgGs from serum samples of vaccinated patients. Binding-SPR assays were performed to study the interaction between anti-PnPs IgGs and PCV13. A robust correlation was found between serum levels of anti-PnPs IgGs, measured by ELISA, and the SPR signal. Moreover, it was possible to correctly classify patients into "non-responder", "responder" and "high-responder" groups according to their specific SPR PCV13 response profiles. SPR technology provides a valuable tool for reliably characterize the interaction between anti-PnPs IgGs and PCV13 in a very short experimental time

    Characterization of electrodeposited zinc oxide/tetrasulphonatedcopper phthalocyanines (ZnO/Ts-CuPc) hybrid films and their photoelectrochemical properties

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    Hybrid films of zinc oxide (ZnO) and tetrasulphonatedcopper phthalocyanine (Ts-CuPc) have been prepared by cathodic electro-deposition from aqueous O2-saturated solutions of ZnCl2 and Ts-CuPc. The Ts-CuPc content of the films can be varied in a wide range by variation of dye concentration in the electro-deposition bath – from single Ts-CuPc molecules embedded in compact crystalline ZnO to films based on an amorphous Ts-CuPc framework. With increasing dye content the colour of the films changes from light blue to deep blue. All films were characterized by XRD, SEM and AFM. Photoelectro-chemical characteristics of the electrodes were studied by photocurrent spectra and by time-resolved photocurrent measurements in 0.1 M KCl electrolyte. At the same time, changes in the electrical and photoelectrical properties of the films are observed, enabling the tuning of these properties in view of optoelectronic applications. Theoretical calculations based on density functional theory (DFT) models were made to understand the optoelectronic properties of the hybrid films. Different parallel and perpendicular orientations were tested. For the most stable hybrid structure, total and projected densities of states of the system were obtained and the alignment of the levels observed
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