生物传感器的研究－电位式酶电极的研制及导电高分子固定化酶的探讨

生物传感器是生物技术与分析技术结合的产物。近年来科学技术的发展，推动了生物传感器的开发。本文叙述了生物传感器的发展和国内、国外的现状，着重地介绍了酶传感器和微生物传感的概况，并介绍了解决现存问题的一些新途径和新的固定化方法：LB膜法，电聚合法，开展了以下生物传感器的研究工作。过氧化氢与钼酸根可以形成几种过氧化物。在一定PH范围内，该过氧化物在PVC膜碘电极上有良好的响应。在过氧化氢存在下，可用PVC膜碘电极测定钼酸根，反过来，在钼酸根存在下，也可用PVC膜碘电极测定过氧化氢，这一特点可用于生物传感器的研究。并对电极响应过程进行了探讨。利用上述PVC膜碘电极可测钼酸根的特点，测定了杨家权子矿样中钼的含量，取得的结果与ZCP发射光谱法测定值基本一致，在测定过程中无需化学分离和加沉淀剂，掩蔽剂，是一种可行的测钼方法。PVC膜碘电极做基础电极，用牛血清白蛋白和茂二醛交联将葡萄糖氯化酶固定到PCV膜碘电极上，制成了一种新型的葡萄糖电极。研究了PH，M_oO_4~(2-)浓度，酯膜厚度和温度对测定的影响。电极响应速度受浓度的影响很大，在一定浓度范围内，可用电位变化速度测定葡萄糖的浓度。在测定过程中，葡萄糖电极的疾性变化较小。对导电高分子固定化酶进行了初步尝试，比较了恒电位与循环伏安两种电聚合吡咯方法。循环伏安法较适于电聚合固定乙醇胶氢酶，辅酶I在酶电极上有响应，可利用此响应测定乙醇。

聚甲基丙烯酸甲酯－－聚四氢呋喃两嵌段共聚物及其共混物的形态和结构

本工作选择文献上少见报道的嵌段共聚物／均聚物结晶型共混体系的相容性和结晶行为作为主要研究方向，合成了系列聚甲基丙烯酸甲酯－－聚四氢呋喃结晶型两嵌段共聚物（PMMA－b－PTHF）为模型化合物，辅之以其它结晶嵌段共聚物，在充分借鉴文献上对非晶嵌段共聚物体系理论和实验研究成果的基础上，系统深入地研究了嵌段共聚物／均聚物结晶型共混体系的相容性和结晶行为。对PMMA－b－PTHF的结晶行为和微相分离结构以及其对不相容体系的增容效应也进行了比较深入的研究。得到了许多重要结果。本工作通过对PTHF－b－PMMA微相分离转变行为的研究，近似确定了PMMA和PTHF间的正的相互作用参数值；对分子量为多分散的PTHF－b－PMMA嵌段共聚物微相分离形态的研究，我们发现分子量为发散的嵌段共聚物的多种微相分离形态并不都存在于多分散体系中。对PTHF-b-PMMA嵌段共聚物结晶行为的研究，发现它与文献上唯一进行过系统研究的PEO－b－PS两嵌段共聚物具有完全不同的微相分离和结晶规律。本工作结果证实了结晶段的结晶能力是决定其相应的结晶－非晶（硬段型）嵌段共聚物相分离和结晶规律的主要因素。本工作首次将近期文献上关于含嵌段共聚物的非晶型稀固体溶液理论及实验研究成果应用于此类结晶型体系。发现在这类体系中共聚物胶束即可起成核剂作用也可起抑制成核的作用，或是对体系的成核行为无影响。微量的共聚物胶束在体系结晶过程中所起作用不同，它们对体系的结晶形态产生的影响也显著不同。决定共聚物胶束作用的主要因素是共聚物结晶段和均聚物的相对结晶能力。本工作的研究结果还表明，共聚物胶束由球形变为非球形时，共聚物胶束的作用也随之发生变化；共聚物胶束的存在还可使体系的微晶结构发生较大的变化，其影响程度主要取决于均聚物的溶体粘度；共聚物结晶段形成胶束核和胶束壳其结晶行为相差很大，在形成胶束核的情况下，不同均聚物分子的溶入对其结晶行为也可产生不同的影响。本工作对PTHF－b－PMMA／PTHF共混体系的研究表明，共混物的相容性及均聚物在其相应的共聚物段微区中的溶解度都可以通过体系的结晶行为来判断。在这一体系中共聚物结晶段的结晶能力随均聚物分数的增加而显著提高。对于宏观相容的PTHF-b-PMMA／PTHF共混体系，其结晶形态随共混组成比的变化而呈现出多种新的特殊结晶形态。研究具有特殊相互作用的嵌段共聚物／均聚物AB／C型共混体系的相容性和结晶行为也是本工作的一个重要研究方向。我们的实验结果表明，这类体系的相容性对组分间的相互作用参数的变化非常敏感，在PTHF－b－PMMA／PEO共混体系中PEO表现出比纯PEO均聚物和PEO／PMMA共混体系复杂得多的结晶行为。它即可异相成核结晶也可均相成核结晶，而且在共混体系中可形成熔点相差十几度的两种结晶结构。对这一体系及PTHF-b-PMMA／PVC共混体系的研究结果还表明，与PTHF部分相容的PEO和PVC溶入PTHF微区后对其结晶行为影响相差很大。通过对PTHF-b-PMMA／PEO体系中PEO均相和异相成核结晶放热量的定量计算。可近似算出在这一体系中，PEO溶入与其部分相容的PTHF微区中的量及这一微区内的组分比。本工作还研究了多个存在特殊互作用的A／C／AB和C／D／AB型增容体系。结果表明，体系中的嵌段共聚物能否起到明显的增容效果，与体系中所有不同组分聚合物间的相容性都有关。由于本工作选择的文献上很少进行过研究的嵌段共聚物／均聚物结晶型共混体系的相容性和结晶行为作为主要研究方向，并进行了深入系统地研究，得到了一些较为重要的结论，这些结论对今后关于这类含结晶嵌段共聚物体系的研究都是很有意义的。

酚及金的柱色谱行为及在线分析方法的研究

研究了以TBP萃树脂为短柱富集填料富集环境样品中和酚类化合物，以及用其在线分析环境样品中的酚类化合物。为了在线分析中洗脱柱色谱行为作者做了探讨，得到了洗脱峰高与样品浓度之间存在的定量关系。并进一步地以PVC－尼龙6复合树脂为柱填料研究了固相萃取金在线分析方法，考察相萃取行为存在的密切联系。

半干旱地区固沙林土壤氮素转化及其有效性研究

土壤氮素（N）转化是生态系统关键的生态学过程之一；而土壤N有效性是沙地生态系统生产力和稳定性的关键限制性因子。以科尔沁沙地东南缘樟子松（pinus sylvestris var．mongolica）、赤松（P.densiflora）和小叶杨（populus simonii）固沙林以及草地为研究对象，采用野外试验和室内实验相结合的方法，全面系统地开展了凋落物分解、土壤N矿化、淋溶等过程及土壤N有效性的研究，旨在揭示半干旱区固沙林土壤N转化及其有效性的特征和机制，为沙地植被恢复、重建、管理和评价提供科学依据。主要结论如下：（1）采用网袋法进行凋落物的分解试验，结果表明不同类型凋落物乘量衰减、元索释放、质员变化均存在明显差异，分解第1年供N能力表现为小叶杨＞草＞樟子松＞赤松；（2）采用PVC顶盖理管法和离子交换树脂袋法分别研究了林地和草地土壤N矿化过程，结果表明土壤N矿化速率表现为小叶杨川章子松七赤松＞草地，N相对有效性表现为赤松＞樟子松＞草地全小叶杨；（3）草地和小叶杨林地土壤N潜在性淋济较高，而樟子松林地较轻；（4）土壤容重、pH值、养分、温度、水分、土壤微生物、土壤动物、林下植被等环境和生物因子反映区域土壤N转化及共有效性的一般特征，而强烈的人类干扰是引起生态系统问差异的关键因索：造林有利于提高沙地土壤N积累和有效性，但樟子松造林30年后才有明显效果：放牧地土壤N硝化速率及其有效性明显高于禁牧地，但质量下降，即NH4+-N/NO3--N失衡，不利于植物吸收、微生物调控和环境保护；（5）赤松、樟子松和小叶杨均为研究区固沙造林的可选树种，合理和科学管理有利于维护生态系统N平衡，实现．可持续经营。

高浓度CO_2下红松幼苗根系呼吸对土壤呼吸的贡献(英文)

本文于2003年5月至10月在长白山森林生态系统定位站内研究了高浓度CO2(500和700靘olmol-1)对红松幼苗土壤呼吸以及根系呼吸对土壤呼吸的贡献。经过4个生长季高浓度CO2的处理,利用LI-6400-09土壤呼吸室对红松幼苗土壤总呼吸和根系呼吸进行了测定。为了区分根系呼吸对土壤总呼吸的贡献,本文采用了PVC管断根法,即每种处理下将三根PVC管插入土壤中30cm以切断根系,从而终止了植物冠层对根系碳水化合物的供应。分别于6月16日、8月20日和10月8日对管内外土壤呼吸进行了测定。结果表明大气和土壤5cm温度都存在明显的日变化,但不同处理之间没有显著差别(P>0.05)。土壤总呼吸和断根土壤呼吸也有明显的日变化和季节变化。不同处理之间土壤总呼吸和断根土壤呼吸差异显著(P<0.01)。6月16日、8月20日和10月8日不同处理下土壤总呼吸和根系呼吸的贡献的平均值分别为3.26、4.78和1.47靘olm-2s-1以及11.5%、43.1%和27.9%。图5表1参38。

Determination of lead using a poly(vinyl chloride)-based crown ether membrane

A poly(vinyl chloride)(PVC)-based membrane of 15-crown-5 exhibits a good response for lead(II) ions over a wide concentration range. The response time of the sensor is 30 s and the membrane can be used for more than four months without observing any divergence. The selectivity of the sensor is comparable with those reported for other such electrodes. It was possible to determine lead in polluted waters using this electrode assembly.

Ion recognition: application of symmetric and asymmetric schiff bases and their complexes for the fabrication of cationic and anionic membrane sensors to determine ions in real samples

Schiff base compounds refer to the branch of supra-molecules and can be used as sensing material in the construction of potentiometric ion selective electrodes (ISEs). This relatively modern field has been subject to extensive research in the period of 1999-2007 when more than 100 ISEs employing Schiff bases were constructed. The quantitative high-throughput detection of 29 cations and 7 anions has been demonstrated in various scientific branches, such as biomedicine, pharmacy, biochemistry, pharmacology, environmental chemistry, food technology, and agriculture. This review discusses Schiff base compounds and their applications in the design and development of ion selective sensors and microsensors.

Mercury selective electrochemical sensor based on a double armed crown ether as ionophore

PVC based membranes of a double armed crown ether, N, N'-dibenzyl, 1,4,10,13-tetraoxa-7, 16-diaza cyclooctadecane (I) as ionophore with sodium tetra phenyl borate (NaTPB) as anion excluder and with many plasticizing solvent mediators have been prepared and used for Hg(II) ion determination. The membrane with DBBP (dibutyl butyl phosphonate ) as plasticizer with various ingredients in the ratio PVC: I: NaTPB: DBBP (150: 12: 2: 100) shows the best results in terms of working concentration range (3.1x10-5-1.0x10-tM) with a Nernstian slope (29.0′0.5 mV/decade of activity). The electrode works in the pH range 2.1-4.5. The response time of the sensor is 15s and it can be used for about 4 months in aqueous as well as in non-aqueous medium. It has good stability and reproducibility. The potentiometric selectivity coefficient values for mono-, di-, and trivalent cations are tabulated. The sensor is highly selective for Hg2+ in the presence of normal interferents like cadmium, silver, sodium and iron.

日本菟丝子对寄主的选择行为

在野外对日本菟丝子(Cuscutajaponica)选择寄主的行为进行观察,结果表明,在所研究的植物群落中,日本菟丝子在不同寄主上发生缠绕的数量多少、发生吸器时间的先后和缠绕比率的大小顺序为枸树、蟛蜞菊、五爪金龙和马缨丹,而从缠绕发生至吸器发生期间日本菟丝子生长点伸长量的大小顺序则相反,且差异显著.日本菟丝子生长点在与聚氯乙烯塑料(PVC)棒接触后24h内发生明显的偏离,而在接触不同寄主后12h内则发生左旋3圈缠绕.多寄主共存的群落比单一寄主群落对日本菟丝子及其寄主的生存均有利.日本菟丝子选择寄主的行为与不同寄主N的含量关系不明显,推测这种选择行为与不同寄主次生物质的差异有关.

Simultaneous synthesis of polyaniline nanotubules and gold nanoplates

This paper describes a facile route for simultaneous synthesis of polyaniline (PANI) nanotubules and gold nanoplates. The inner diameter of PANI nanotubules was less than 10 nm and the length was several micrometers. At the same time, uniform single-crystal gold nanoplates with thicknesses of tens of nanometers were obtained.

Micelle-assisted synthesis of polyaniline/magnetite nanorods by in situ self-assembly process

Polyaniline/magnetite nanocomposites consisting of polyaniline (PANI) nanorods surrounded by magnetite nanoparticles were prepared via an in situ self-assembly process in the presence of PANI nanorods. The synthesis is based on the well-known chemical oxidative polymerization of aniline in an acidic environment, with ammonium persulfate (APS) as the oxidant. An organic acid (dodecylbenzenesulfonic acid, DBSA) was used to replace the conventional strong acidic (1 M HCl) environment. Here, dodecylbenzenesulfonic acid is used not only as dopant, but also as surfactant in our reaction system.

Full View of Single-Molecule Force Spectroscopy of Polyaniline in Oxidized, Reduced, and Doped States

The macroscopic mechanical properties of polyaniline (PANI) lie mainly on two factors, the structure of molecular aggregations of polymers and the mechanical properties of a single polymer chain. The former factor is swell revealed; however, the latter is rarely studied. In this article, we have employed atomic force microscopy-based single-molecule force spectroscopy to investigate the mechanical properties of a kind of water-soluble PANI at a single-molecular level. We have carried out the study comparatively on single-chain-stretching experiments of oxidized, reduced, and doped PANI and obtained a full view of the single-chain elasticity of PANI in all these states. It is found that oxidized and reduced PANI chains are rigid, and the oxidized PANI is more rigid than the reduced PANI. Such a difference in single-chain elasticity can be rationalized by the molecular structures that are composed of benzenoid diamine and quinoid diimine its different proportions. The doped PANI has been found to be more flexible than the oxidized and reduced PANI, and the modified freely jointed chain parameters of doped PANI are similar with those of a common flexible-chain polymer.

Polyaniline/Pt Hybrid Nanofibers: High-Efficiency Nanoelectrocatalysts for Electrochemical Devices

A simple and facile procedure to synthesize a novel hybrid nanoelectrocatalyst based on polyaniline (PANI) nanofiber-supported supra-high density Pt nanoparticles (NPs) or Pt/Pd hybrid NPs without prior PANI nanofiber functionalization at room temperature is demonstrated. This represents a new type of ID hybrid nanoelectrocatalyst with several important benefits. First, the procedure is very simple and can be performed at room temperature using commercially available reagents without the need for templates and surfactants. Second, ultra-high density small "bare" Pt NPs or Pt/Pd hybrid NPs are grown directly onto the surface of the PANI nanofiber, without using any additional linker. Most importantly, the present PANI nanofiber-supported supra-high density Pt NPs or Pt/Pd hybrid NPs can be used as a signal enhancement element for constructing electrochemical devices with high performance.

Controlled synthesis of nanoporous Au microsheet via surfactant emulsion template

A facile and wet-chemical approach was employed to control synthesis of self-organizing, hyperbranched nanoporous Au microsheet with high quality in bulk quantity. This method produced nanoporous Au microsheets with a thickness of 7-15 nm. The microsheets were composed of irregularly interconnected planar Au nanoplates with interstices, i.e. nanopores of 10-50 nm. And the nanoporous Au microsheets were enveloped in 10-30 nm thick polyaniline (PANI) sheaths. The morphology of the nanostructured Au composites could also be easily tuned by changing the concentration of aniline and chlorauric acid. The dendritic and epitaxial growth of nanoporous Au microsheet was believed as the diffusion-limited process confined in the lamellar emulsion phase through self-assembly of aniline and dodecylsulfate. The solution reaction proceeded at a mild condition (room temperature and aqueous solutions), and less toxic reagents were employed instead of extreme toxic and corrosive chemicals.

A novel approach to synthesis of functional CPVC and CPE or graft copolymers - in situ chlorinating graft

A new process of graft copolymerization of poly(vinyl chloride) (PVC) and polyethylene (PE) with other monomers was developed. The grafted chlorinated poly(vinyl chloride) (CPVC) and chlorinated polyethylene (CPE) were synthesized by in situ chlorinating graft copolymerization (ISCGC) and were characterized. Convincing evidence for grafting and the structure of graft copolymers was obtained using FT-IR, H-1-NMR, gel permeation chromatography (GPC), and the vulcanized curves. Their mechanical properties were also measured. The results show that the products have different molecular structure from those prepared by other conventional graft processes. Their graft chains are short, being highly branched and chlorinated. The graft copolymers have no crosslinking structure. The unique molecular structure will make the materials equipped with special properties.