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101.
Franck Charmantray Nadia Touisni Laurence Hecquet Thierry Noguer Christine Mousty 《Electroanalysis》2015,27(6):1341-1344
This paper describes the development of an amperometric biosensor based on galactose oxidase (GAOx) immobilization within a laponite clay film deposited on Carbon Screen‐Printed Electrodes modified by electrodeposited Prussian Blue and coated with poly‐(O‐phenylenediamine) (PPD/PB/CSPEs). Amperometric performances of GAOx@laponite/PPD/PB/CSPEs bioelectrodes were determined using several GAOx substrates. Using these modified electrodes the reduction of enzymatically generated hydrogen peroxide was performed at ?0.2 V vs. Ag‐AgCl. In an initial attempt, E.Coli transketolase activity on its immobilized form was followed using a bienzymatic GAOx‐TK biosensor. 相似文献
102.
An electrochemical biosensor capable of indirect detection of DNA damage induced by any one of the three endocrine-disrupting compounds (EDCs) – bisphenol A (BPA), 4-nonylphenol (NP) and 4-t-octylphenol (OP), has been researched and developed. The methylene blue (MB) dye was used as the redox indicator. The glassy carbon electrode (GCE) was modified by the assembled dsDNA/graphene oxide-chitosan/gold nano-particles to produce a dsDNA/GO-CS/AuNPs/GCE sensor. It was characterized with the use of electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and scanning electron microscopy (SEM) techniques. The loading/release of the MB dye by the dsDNA/GO-CS/AuNPs film was investigated, and the results showed that the process was reversible. Based on this, the sensor was used to measure the difference between the loading capabilities of intact and damaged dsDNA in the films. The sensor was then successfully applied to detect DNA damage electrochemically. The differential pulse voltammetry (DPV) peak current ratio for MB, observed before and after DNA damage, increased linearly in the presence the BPA, NP or OP compounds; the treatment range was 10–60 min, and the respective damage rates were 0.0069, 0.0044 and 0.0031 min−1, respectively. These results were confirmed by the binding constants: 2.09 × 106 M−1 (BPA-DNA), 1.28 × 106 M−1 (NP-DNA) and 9.33 × 105 M−1 (OP-DNA), all of which were obtained with the use of differential pulse stripping voltammetry (DPSV). 相似文献
103.
Yu-Qiao GUAN Gang CHEN Juan SONG Cheng-Xin WANG Yan QIAN Qin ZHANG Ling-Ling DENG Zeng-Qin FENG Wen-Juan SHANG You-Tian TAO Shu-Fen CHEN Lian-Hui WANG Wei HUANG 《物理化学学报》2017,33(4):816-822
We synthesized a series of novel spiro[fluorene-9, 9'-xanthene] (SFX)-based host materials via a one-step palladium-catalyzed cross-coupling reaction. These materials have high triple energy levels and high yield, and thus can be used as hosts for blue phosphors. Blue phosphorescent organic light-emitting devices (PHOLEDs) with a bis (3, 5-difluoro-2-(2-pyridyl) phenyl-(2-carboxypyri-dyl) iridium (Ⅲ) (FIrpic) emission were fabricated. Furthermore, we applied cohosts composed of one of the new synthesized materials and the hole transport material di-[4-(N, N-ditolyl-amino)-phenyl]cyclohexane (TAPC) to the blue PHOLEDs to successfully acquire efficient blue emissions. The SFX-based material provided efficient energy transfer while TAPC improved the mobility of the cohost as well as reduced the working voltage. Maximum current efficiencies of 22.56 and 25.93 cd·A-1 and the maximum brightnesses of 6421 and 6196 cd·m-2 were obtained for the PHOLEDs with TAPC: 2-(9-phenyl-fluoren-9-yl) spiro[fluorene-9, 9'-xanthene] (PF-SFX) and TAPC: 2-(9-(4-(octyloxy)-phenyl)-9H-fluoren-9-yl) spiro[fluorene-9, 9'-xanthene] (C8OPF-SFX) cohosts, respectively. The experimental results obtained for the four SFX-based host materials were enough to declare that SFX is an effective main unit that can be used to build efficient host materials for blue phosphors containing only C, H, and O basic elements. 相似文献
104.
Yang CHEN Xiao-Yan YANG Peng ZHANG Dao-Sheng LIU Jian-Zhou GUI Hai-Long PENG Dan LIU 《物理化学学报》2017,33(10):2082-2091
以水热制备的ZnO纳米棒为基底,通过乙二醇液相还原法负载不同贵金属颗粒(Pt、Pd、Ru)构筑贵金属负载的ZnO纳米棒复合光催化剂。实验结果表明在制备条件相同时,Pt/ZnO样品中Pt颗粒尺寸较小,分布均匀;Pd/ZnO样品中Pd颗粒尺寸较大且团聚严重;Ru/ZnO样品则几乎没有Ru颗粒负载。在紫外光照射下降解亚甲基蓝的反应中,Pt/ZnO表现出最高的光催化性能,Pd/ZnO样品次之,而Ru/ZnO则表现出与ZnO纳米棒相似的光催化活性;表明小尺寸和大小均匀的贵金属颗粒对ZnO纳米棒的催化性能有着显著的提升作用。对Pt/ZnO来说,当Pt载量为3.2%时Pt/ZnO催化剂的光催化活性最高。 相似文献
105.
106.
Michael Coto Giorgio Divitini Avishek Dey Satheesh Krishnamurthy Najeeb Ullah Cate Ducati R. Vasant Kumar 《Materials Today Chemistry》2017
A highly efficient black TiO2-Ag photocatalytic nanocomposite, active under both UV and visible light illumination, was synthesized by decorating the surface of 25 nm TiO2 particles with Ag nanoparticles. The material was obtained via a rapid, one-pot, simple (surfactant and complexing agent free) chemical reduction method using silver nitrate and formaldehyde as a metal salt and reducing agent, respectively. The nanocomposite shows an increase of over 800% in the rate of photocatalytic methylene blue dye degradation, compared to commercial unmodified TiO2, under UV-VIS illumination. Unlike pure TiO2, the nanocomposite exhibits visible light activation, with a corresponding drop in optical reflectance from 100% to less than 10%. The photocatalytic properties were shown to be strongly enhanced by post-reduction annealing heat treatments in air, which were observed to decrease, rather than coarsen, silver particle size, and increase particle distribution. This, accompanied by a variation in the silver surface oxidation states, appear to dramatically affect the photocatalytic efficiency under both UV and visible light. This highly active photocatalyst could have wide ranging applications in water and air pollution remediation and solar fuel production. 相似文献
107.
Here we report the characterization of an electrochemical mercury (Hg2+) sensor constructed with a methylene blue (MB)-modified and thymine-containing linear DNA probe. Similar to the linear probe electrochemical DNA sensor, the resultant sensor behaved as a “signal-off” sensor in alternating current voltammetry and cyclic voltammetry. However, depending on the applied frequency or pulse width, the sensor can behave as either a “signal-off” or “signal-on” sensor in square wave voltammetry (SWV) and differential pulse voltammetry (DPV). In SWV, the sensor showed “signal-on” behavior at low frequencies and “signal-off” behavior at high frequencies. In DPV, the sensor showed “signal-off” behavior at short pulse widths and “signal-on” behavior at long pulse widths. Independent of the sensor interrogation technique, the limit of detection was found to be 10 nM, with a linear dynamic range between 10 nM and 500 nM. In addition, the sensor responded to Hg2+ rather rapidly; majority of the signal change occurred in <20 min. Overall, the sensor retains all the characteristics of this class of sensors; it is reagentless, reusable, sensitive, specific and selective. This study also highlights the feasibility of using a MB-modified probe for real-time sensing of Hg2+, which has not been previously reported. More importantly, the observed “switching” behavior in SWV and DPV is potentially generalizable and should be applicable to most sensors in this class of dynamics-based electrochemical biosensors. 相似文献
108.
109.
Marie Kueny-StotzHind Mamlouk-Chaouachi Delphine Felder-Flesch 《Tetrahedron letters》2011,52(22):2906-2909
In the last decade, methods for the precise localization of sentinel lymph node (SLN) have drawn tremendous attention by oncology surgeons and researchers in the field of medical diagnosis. The accurate identification and characterization of lymph nodes by imaging has important therapeutic and prognostic significance in patients with newly diagnosed cancers. The SLN is the first lymph node that receives lymphatic drainage from the site of a primary tumor. Two biocompatible dendronized phosphonates, one bearing a Patent Blue (PB VF) dye at its periphery, where synthesized. Indeed, such a blue dye is currently injected to label the lymph node system for its per-operative detection. Therefore, developing chemistry of Patent Blue VF to optimize early diagnosis is of great current interest. 相似文献
110.
Sourav Adak Luke L. Daemen Monika Hartl Darrick Williams Jennifer Summerhill Heinz Nakotte 《Journal of solid state chemistry》2011,184(11):2854-2861
We present a comprehensive study of the structural properties and the thermal expansion behavior of 17 different Prussian Blue Analogs (PBAs) with compositions MII3[(M′)III(CN)6]2·nH2O and MII2[FeII(CN)6]·nH2O, where MII=Mn, Fe, Co, Ni, Cu and Zn, (M′)III=Co, Fe and n is the number of water molecules, which range from 5 to 18 for these compounds. The PBAs were synthesized via standard chemical precipitation methods, and temperature-dependent X-ray diffraction studies were performed in the temperature range between −150 °C (123 K) and room-temperature. The vast majority of the studied PBAs were found to crystallize in cubic structures of space groups Fm3?m, F4?3m and Pm3?m. The temperature dependence of the lattice parameters was taken to compute an average coefficient of linear thermal expansion in the studied temperature range. Of the 17 compounds, 9 display negative values for the average coefficient of linear thermal expansion, which can be as large as 39.7×10−6 K−1 for Co3[Co(CN)6]2·12H2O. All of the MII3[CoIII(CN)6]2·nH2O compounds show negative thermal expansion behavior, which correlates with the Irving–Williams series for metal complex stability. The thermal expansion behavior for the PBAs of the MII3[FeIII(CN)6]2·nH2O family are found to switch between positive (for M=Mn, Co, Ni) and negative (M=Cu, Zn) behavior, depending on the choice of the metal cation (M). On the other hand, all of the MII2[FeII(CN)6]·nH2O compounds show positive thermal expansion behavior. 相似文献