A novel flow through optical fiber biosensor for glucose based on luminol electrochemiluminescence

A novel flow injection optical fiber biosensor for glucose based on luminol electrochemiluminescence (ECL) is presented. The sol-gel method is introduced to immobilize glucose oxidase (GOD) on the surface of a glassy carbon electrode. After optimization of the working conditions, glucose could be quantitated in the concentration ranges between 50 muM and 10 mM with a detection limit of around 26 muM. Signal reproducibility was about 3.62% relative standard deviation for 11 replicated measurements of 0.1 mM glucose. The ECL biosensor also showed good selectivity and operational stability. The proposed method can be applied to determination of glucose in soft drink samples.

Covalently attached multilayer assemblies containing photoreactive diazo-resins and conducting polyaniline

We reported on the multilayer architecture containing diazo-resins (DAR) as polycations and polyaniline poly(aniline-co-N-propanesulfonic acid aniline) (PAPSAH) as polyanions held together by electrostatic interaction. Upon UV irradiation, the adjacent interfaces of the multilayer reacted to form a covalently crosslinking structure which greatly improved the stability of the films as confirmed by solvent etching experiments. These changes were confirmed by UV-Vis and FTIR spectroscopy. The thickness of the covalently attached films were characterized with small angle X-ray diffraction (SAXD) and a value of 30.0 Angstrom per bilayer was obtained. This type of film was further characterized by cyclic voltammetry which showed that the electroactive property of PAPSAH was still kept in the films after photoreaction. (C) 2000 Elsevier Science B.V. All rights reserved.

Protein structural characterization by scanning tunneling microscopy with electrochemistry

The structure characterization of proteins or enzymes by STM on electrochemically prepared HOPG surface studied in this laboratory is reviewed. The serial structures of Hb were observed. The differences between the denaturation and inactivation of HRP were investigated by in situ and ex situ STM. The structural variation of Hb in an organic solvent was imaged while protein denaturation was easily observed in a polar solvent.

Synthesis and characterization of novel sodium sulfonate-functionalized poly(ether ether ketone)s containing cyclohexyl side groups

Novel water insoluble sodium sulfonate-functionalized poly(ether ether ketone)s containing cyclohexylidene in the main chain with degree of sulfonation up to 2.0 were synthesized from nucleophilic polycondensation of 5, 5'-carbonylbis (2-fluorobenzenesulfonate), 4, 4'-difluorobenzophenone and 4, 4'-cyclohexylidenebisphenol. The polymers showed excellent thermal stability and good water resistance as well. The DSC diagrams and WAXD patterns indicated an amorphous morphological structure of these polymers. A comprison of some properties between these copolymers and polymers derived from bisphenol A was given.

含亚环己基荷电聚醚醚酮的合成表征与性能

以 3,3′ 二磺酸钠基 4,4′ 二氟二苯酮和 4,4′ 二氟二苯酮与 4,4′ 亚环己基双酚进行亲核共缩聚 ,合成了磺化度从 0 4～ 2 0的一系列含亚环己基的荷电聚醚醚酮 .聚合物除保持了荷电聚醚醚酮良好的热稳定性和机械性能外 ,还具有良好的耐水性 .聚合物的DSC和广角X射线衍射数据表明 :上述磺化度聚合物均呈无定型聚集态结构 .比较了聚合物与双酚A系列荷电聚醚醚酮的性能差异 ,讨论了聚合物的溶解特点

YBa_2Cu_3O_7的化学键性质和穆斯堡尔谱的研究

利用电介质的平均能带模型计算了YBa2 Cu3O7的化学键参数 ,得到Cu(1)—O键的平均共价性为 0 40 6,Cu(2 )—O键的平均共价性为0 2 76。应用化学环境因子计算了Fe :Y 12 3的穆斯堡尔同质异能位移 ,确定了5 7Fe在Y 12 3中的价态和占位情况。由电声子强度参数与共价性的关系说明了超导相中Cu(2 )离子的重要性

Using triazine as coupling unit for intramolecular ferromagnetic coupling of multiradicals

Novel high spin tri-, tetra-, pentaradicals, composed of triazine coupling units and cationic amino radical spin centers (+ . NH) under various configurations and linkages, are predicted from AM1-CI calculations. It is found that for charged planar multiradicals the stability of high spin ground states depends on both the molecular configuration and the number of end groups. Generally, cyclic 1,3-bridged charged multiradicals (S less than or equal to 5/2) possess more stable high spin ground states than their isomers under the branched 1,3,5,-bridged configuration. Therefore, it is suggested that in the design of planar high spin molecules with stable high spin ground states, less end groups and all the supposed spin centers and/or the coupling units should be under the same structural situation. (C) 1999 Elsevier Science B.V. All rights reserved.

一维结构中的发光特性

具有低维结构尤其是一维结构的物质往往具有较特殊或更优异的性质。本文研究了具有一维结构的发光物质的发光特性与微观结构之间的关系，得到了某些规律，即在一维结构中，只有存在相对较短的M-O键才可能引起电荷迁移产生发光；在该化合物中M应为变价元素且低价态具有发光性质；一维键上的能量传输往往具有很高的发光猝灭浓度和可能存在发光中间体

Intramolecular energy transfer mechanism between ligands in ternary rare earth complexes with aromatic carboxylic acids and 1,10-phenanthroline

A series of binary and ternary rare earth (Gd, Eu, Tb) complexes with aromatic acids and 1,10-phenanthroline have been synthesized. The lowest triplet state energies of ligands have been obtained by measuring the phosphorescence spectra of binary gadolinium complexes. By comparing the phosphorescence spectra of binary complexes with those of ternary ones, it is found that there exists another intramolecular energy transfer process from the aromatic acids to 1,10-phenanthroline besides the intramolecular energy transfer process between the aromatic acids and the central rare earth ions. The intramolecular energy transfer efficiencies have been calculated by determining phosphorescence lifetimes of binary and ternary gadolinium complexes. The luminescence properties of corresponding europium and terbium complexes are in agreement with the prediction based on energy transfer mechanism. (C) 1998 Elsevier Science S.A. All rights reserved.

Novel morphology in ring-banded spherulites from single-phase mixtures of poly(epsilon-caprolactone) with poly(styrene-co-acrylonitrile)

Novel morphology of ring-banded spherulites in the surface of poly(epsilon-caprolactone)/poly(styrene-co-acrylonitrile) (PCL/SAN) blends was discovered and studied by SEM and TEM. The ring-banded spherulites separate into those exhibiting a very dark contrast, of relatively regular bundles of lamellae and others appearing with a much brighter intensity, of a coarse and irregular aggregates of lamellae. The origin of the novel morphology is not due to different crystalline structures as in the case of isotactic polypropylene because only one crystal structure exists in PCL/SAN blends. The formation may reflect whether spherulites in PCL/SAN blends are nucleated at the bottom surface or at the top (free) surface.

Enzymatic degradation of poly(epsilon-caprolactone) film in phosphate buffer solution containing lipases

The enzymatic degradation of poly(epsilon-caprolactone) (PCL) films in phosphate buffer solution containing lipases has been studied by DSC, WAXD and SEM. Three lipases, pseudomonas lipase (PS), porcine pancreatic lipase (PP), and candida cylindracea lipase (AY), were used. The results showed that the degradation of PCL films in phosphate buffer solution containing PP or AY was very slow: no weight loss could be found within 1 week. However, PCL film could degrade rapidly and completely within 4 days in phosphate buffer solution containing PS lipase. (C) 1997 Elsevier Science Limited.

Radiation-induced crystallization of polyamide-1010 containing heterogeneous nuclei

Radiation-induced crystallization of polyamide-1010 (PA1010) or nylon-1010 containing heterogeneous nuclei (neodymium oxide, Nd2O3) is discussed in this paper by Wide Angle X-ray Diffraction (WAXD) and Differential Scanning Calorimetry (DSC). The results show that at low dosage the crystallinities of the irradiated specimens increase, while crystallite size (L(hkl)) decreases, indicating that some new crystallites are produced in the course of irradiation. The new centers were brought about in the fold surface of the lamellae. Copyright (C) 1997 Elsevier Science Ltd

辐射增强 PP/LDPE 共混体系力学性能的研究

研究了在多官能团单体—三烯丙基异腈脲酸酯存在下，ＰＰ／ＬＤＰＥ共混物的辐射效应，并用ＳＥＭ、ＤＳＣ和动态力学性能对其形态结构和相容性进行了表征。结果表明：通过添加三烯丙基异腈脲酸酯，用辐射可以强化ＰＰ／ＬＤＰＥ共混物的相间结合力，改善共混物的相容性，从而提高共混物的力学性能。

Al_2O_3-B_2O_3-Ce_2O_3体系相关系的研究

Ａｌ２Ｏ３Ｂ２Ｏ３Ｃｅ２Ｏ３体系相关系的研究尤洪鹏洪广言（中国科学院长春应用化学研究所，长春１３００２２）ＩｎｖｅｓｔｉｇａｔｉｏｎｏｎＰｈａｓｅＲｅｌａｔｉｏｎｓｉｎｔｈｅＳｙｓｔｅｍＡｌ２Ｏ３Ｂ２Ｏ３Ｃｅ２Ｏ３ＹｏｕＨｏｎｇｐｅｎｇＨｏｎ...