Interaction between poly（amidoamine） dendrimers and DNA studied by spectroscopic methods

The interaction between amino-terminated, and ethylenedtamine core poly（amtdoamine） （PAMAM） dendrimers and herring sperm DNA was investigated by various spectroscopic methods including UV spectroscopy, fluorescence spectroscopy, microscopic FTIR- and circular dichroism （CD-） spectroscopy. Ethidium bromide （EB） is used as a nucleic acid probe for this study. Experimental results show that PAMAM dendrimers can form stable complexes with DNA and the dendrimers bind to DNA sufficiently strong which cannot be displaced by EB, and we also found that the formation of the complexes can cause the conformation change of the DNA secondary structure. According to the Scatchard analysis, the association constant of PAMAM to DNA is calculated to be 2.53×10^4 mol/L^-1.     

Fluorescence study on the interactions of PAMAM dendrimers and their derivatives with bovine serum albumin

The interactions of amino-terminated, and ethylenediamine core poly（amidoamine） （PAMAM） dendrimers and their derivatives with bovine serum albumin （BSA） were investigated by fluorescence spectroscopy. Experimental results showed that the fluorescence intensity of BSA decreased after the addition of different modified dendrimers, and the extent of the fluorescence quenching caused by various modified dendrimers strongly depends upon the different functional groups on their surfaces. We also investigated the influence of pH and ionic strength on the interaction between various modified dendrimers and BSA. Circular dichroism （CD） spectroscopic measurements showed that the content of α-helix structure of BSA decreased after the addition of different modified dendrimers, which indicated that dendrimers induced changes in the secondary structure of BSA.     

Synthesis,characterization, and tunable wettability of poly(ionic liquid) brushes via nitroxide-mediated radical polymerization (NMP)

Well-defined poly (ionic liquid) brushes with tunable wettability are successfully synthesized via nitroxide-mediated radical polymerization. X-ray photoelectron spectroscopy, attenuated total reflection infrared spectroscopy and static water contact angle measurements are used to monitor each step. Ellipsometry, nuclear magnetic resonance (1H and 13C) spectra and gel permeation chromatographic measurements reveal that there is a linear increase in polymer film thickness with polymerization time, indicating that chain growth from the surface is a controlled/“living” polymerization. The surface morphology was measured by atomic force microscopy. Moreover, the surfaces of the poly (ionic liquid) brushes with tunable wettability and reversible switching between hydrophilicity and hydrophobicity can be easily achieved by counteranion exchange.     

含一种蒽醌结构红色水性聚氨酯的制备及表征

以聚（2-甲基-1,3-丙二醇-己二酸）酯二醇（PMA-1000）,2,2-二羟甲基丙酸（DMPA）,甲苯二异氰酸酯（TDI）,1,4-丁二醇（BDO）,1-（（2-羟基乙基）氨基）蒽醌（SR222）为原料,三乙胺（TEA）为中和剂,乳化后得到含SR222的红色水性聚氨酯染料（SR222-WPU）.利用红外光谱仪、荧光分光光度计、激光粒度仪、分光测色仪、色牢度测试仪对产物的结构和性能进行表征.结果表明,SR222蒽醌结构接到水性聚氨酯链上,合成了SR222-WPU,其乳液在300~475 nm波段具有紫色荧光;随着SR222添加量的增加,SR222-WPU乳液粒径从58.71 nm增大到86.6 nm,胶膜的a*值从21.26增大到79.64,红色逐渐加深;SR222-WPU在棉布上色牢度较好,耐摩色牢度为4~5级,耐水渍褪色度为5级.      

Green Light-Emitting Region-Regular Poly（9,9-Dihexylfluorene-co-Fluorenone） Prepared from Solvent-Free Oxidative Coupling Polymerization

Soluble green light-emitting poly（9,9-dihexylfluorene- co-fluorenone） was synthesized by solvent-free oxidative coupling polymerization of 9,9-dihexylfluorene in a facile one-step reaction. The polymers were characterized by FT-IR, ^1H NMR, ^13C NMR, UV-Vis and fluorescence spectroscopy. The region-regular structure of the polymer linking at 2, 7＇-position on the fluorene moieties was obtained. The FT-IR spectra of the polymers showed fluorenone vibration. The fluorescence spectra of the solid thin film of the polymers displayed green light-emitting, which was emitted from fluorenone moieties produced in the polymerization process.     

基于亚甲基蓝与DNA相互作用自铸成膜研究

基于亚甲基蓝（MB）与DNA间的静电作用与嵌入作用，运用自铸膜法在载玻片上制备了蓝色的MB-DNA复合膜，并应用紫外可见光谱法、荧光光谱法和扫描电镜等方法对复合膜进行了表征，同时研究了DNA-MB复合膜的成膜机制.结果表明，MB能嵌入诱导DNA的凝聚，形成均匀的MB-DNA复合膜，而膜中的DNA对MB起着分散剂的作用，使膜中多聚MB分散成单体和二聚的形式，显示出单体和二聚体的光吸收特性.该研究结果为DNA介导的功能光电器件的构筑提供了有力的支撑.     

用于甲醛检测的比率型荧光探针合成及性能研究

本文设计合成了一种以萘酰亚胺为荧光团的比率型荧光探针,探针的设计基于萘酰亚胺苯环侧链上的醛基被取代后,荧光发射波长红移且荧光强度减弱,与甲醛反应后,发生2-aza-Cope重排反应,醛基恢复,荧光发射波长蓝移且荧光强度增强,可以此作为甲醛定性定量检测依据。通过核磁共振波谱法、高分辨质谱法和荧光光谱法对比率型荧光探针的结构、性质和检测性能进行了表征和研究,测试结果表明该探针对甲醛具有很好的检测性能,相较于传统荧光探针具有选择性好、灵敏度高、检测下限低等特点。     

双核磺化酞菁钴掺杂聚苯胺膜的制备和表征

采用电聚合方法制成不同浓度双核磺化酞菁钴(bi-CoPc)掺杂的聚苯胺(PAn-bi-CoPc)膜,并用电化学、紫外-可见-近红外光谱、红外光谱、扫描电子显微镜及电导率进行了表征.结果表明:酞菁浓度对膜的电化学行为有影响,PAn膜和PAn-bi-CoPc膜在近红外区都有较宽的吸收带,当bi-CoPc为1 mmol/L时,PAn-bi-CoPc膜在近红外区出现明显的吸收峰,膜在近红外区的吸收强度随酞菁浓度增加而下降;红外光谱发现掺杂后酞菁的共轭体系得到加强.     

聚氧乙烯单甲醚改性聚酰胺-胺的造纸助留增强性能

采用Michael加成反应制备了聚氧乙烯单甲醚(MPEO-A-1000)改性的聚酰胺一胺树形聚合物(MnG,n=4.0,5.0),研究了该MnG及其与阴离子聚丙烯酸钠、丙烯酸钠改性的聚酰胺-胺树形聚合物复配的助留增强体系在阔叶木浆料中所起到的助留和增强效果.结果表明:M4.0G及其与丙烯酸钠改性的聚酰胺-胺树形聚合物复配的双元助留体系的纸样助留率和物理强度均比空白纸样明显提高.     

支化共轭齐聚物/介孔二氧化硅复合物的合成及荧光猝灭性能

通过Heck缩聚反应合成支化型聚芴/聚对苯乙烯撑(PFO/PPV)共轭齐聚物并且与介孔二氧化硅MCM-41复合成主-客体材料.使用紫外吸收光谱、荧光光谱手段表征了介孔复合薄膜的光化学性能.研究了该复合膜对硝基芳香烃物质的荧光猝灭性能.实验结果表明该介孔复合物比一般的共轭高分子检测灵敏度更高,使用期限更长,在硝基芳香烃爆炸性物质的检测上有着潜在的应用价值.     

CdSe量子点/聚酰胺-胺树形分子纳米复合材料的制备与表征

以NaHSe为硒源,以聚酰胺-胺树形分子(PAMAM)为内模板,在水溶液中制备了尺寸均一、分散良好、荧光性强的CdSe量子点.分别用紫外-可见吸收光谱、荧光发射光谱和高分辨透射电镜对树形分子包裹的CdSe量子点进行表征.结果表明:在紫外光的激发下,树形分子与CdSe量子点间发生了强烈的界面电荷转移作用.质子化后整代数树形分子模板作用优于半代数树形分子.高代数树形分子的模板作用优于低代数树形分子.pH在7.5时,纳米簇粒径小而均匀,且溶液稳定性高.改变Cd2+与PAMAM物质的量比,可得到一系列尺寸不同、发光颜色不同的CdSe量子点.0℃低温时制备的量子点光致发光效率最高.     

医用聚氯乙烯的表面磺酸化及抗凝血性能研究

利用SO2/O2混合气体等离子体处理医用聚氯乙烯(PVC)膜，在材料表面引入磺酸基，借助X射线光电子能谱和ATR-FTIR光谱对膜表面的组成及结构进行表征，通过动态凝血实验以及凝血酶原时间、部分凝血活酶时间、凝血酶时间的测定，对聚氯乙烯膜的抗凝血性能进行评价．实验结果表明，等离子体处理聚氯乙烯膜可以在材料表面有效地引入磺酸基，显著提高材料的抗凝血性能．     

乙醇脱氢酶在聚苯胺-聚丙烯酸修饰电极上的固定及表征

采用循环伏安法在铂电极上于0．5mol／L苯胺-2．5mol／LHCI-15％（质量分数）聚丙烯酸的水溶液中制备聚丙烯酸掺杂的聚苯胺膜；并在0．25mol／L磷酸氢二钠-柠檬酸缓冲溶液（pH=7）中测试掺杂后的聚苯胺膜的电化学性能，聚苯胺-聚丙烯酸（PAn-PAA）复合膜修饰电极在电位为-0．2～0．4V时出现1对稳定的氧化还原峰，与PAn修饰电极相比，它在此中性缓冲溶液中具有更好的导电性和电化学活性，可用作固定酶的载体和酶催化反应的电子传递媒介。实验中采用两步法将乙醇脱氢酶（ADH）固定至PAn-PAA复合膜中，用循环伏安（CV）、交流阻抗（EIS）和扫描电镜（SEM）等方法对固定乙醇脱氢酶前后膜的性能进行表征。结果表明ADH已固定至复合膜中。     

Probing the microenvironment of an oligo-（p-phenylene vinylene） derivative encapsulated in polymer-impregnated sol-gel silica matrix

Polymer-impregnated silica sol-gel composite materials are hosts for organics in advanced optics application. An oligo-phenylene vinylene derivative 4,4‘-(1,4-phenylene dithenylene)-bis-(N-methyl pyridinium iodide) (OPVD) was introduced to poly(hydroxyethyl methacrylate) (PHEMA)-impregnated silica composite film by the sol-gel process. By comparing the X-ray diffraction, UV-visible spectra, steady-state and time-resolved fluorescence spectra of OPVD in three solid matrices (PHEMA/silica composite film, pure PHEMA film, and pure silica film), the similar results of PHEMA/silica composite film and pure PHEMA film demonstrate that the OPVD is primarily surrounded by a PHEMA-like environment in the composite matrix. The model of such structure is presented, which is useful for further understanding and optimizing of properties of doped sol-gel materials.     

低代数聚酰胺-胺树状高分子的合成

用发散法合成了0.5～4.0代聚酰胺-胺（PAMAM）树状高分子,以PAMAM G3.5,PAMAM G4.0树状高分子为例,采用傅里叶变换红外光谱仪、1H和13C超导核磁共振谱仪对其分子结构进行表征,并对聚酰胺-胺树状高分子合成的影响因素作了讨论.     

新型1，8-萘酰亚胺衍生物的合成及其分子内光致电子转移

合成了4－哌吡嗪基－N－甲基－1,8－萘酰甲亚胺（NA1）及其衍生物。化合物NA1和4－（4－甲基－1－哌吡嗪基）－N－甲基－1,8－萘酰亚胺（NA2）分子内的脂肪胺作为电子给体,通过双碳链向萘酰亚胺进行光致电子转移,使得N－甲基－1,8－萘酰亚胺荧光团的荧光猝灭;脂肪胺质子化或季铵化后,光致电子转移过程中断、荧光恢复。这类化合物的荧光随pH值的变化而变化,表现出的荧光分子开关功能。     

A novel water-soluble anionic conjugated copolymer containing poly（p-phenylene vinylene） segments： Copolymer synthesis and multilayer construction by assembling poly（diallyl dimethyl ammonium chloride）

This paper reports the synthesis of a water soluble conjugated polymer poly（p-phenylene vinyleneco-sodium methacrylate） （ws-P（PV-co-SMA）） and the multilayer of the derived copolymer assembling poly（diallyl dimethyl ammanium chloride） （PDDA）. The self-assembling process of the multilayer was monitored by UV-vis absorption spectroscopy, and the data indicated a linear increase in film thickness with a number of ws-P（PV-co-SMA）/PDDA bilayers. The alternative deposition of ws-P （PV-co-SMA） and PDDA allowed the insertion of a non-conjugated layer between the conjugated layers, thus the migration of the photogenerated polarons was effectively confined in the isolated ws-P （PV-co-SMA） chains. Consequently, the photoluminescence quantum yield reached 0.68, 30 times higher than that of pure poly（p-phenylen vinylene）. The distinct electronic interactions between conjugated segments were confirmed by comparative analyses of the excitation spectra and time-resolved photoluminescence spectra of ws-P（PV-co-SMA） solid film and the assembled multilayers. The confinement effect of the PDDA layer on the photogenerated carriers was verified by the surface photovoltage spectroscopic measurement on both ws-P（PV-co-SMA） solid film and self-assembled multilayers.     

Effect of bilayer number on the photoluminescent property of TPE-based self-assembled film

Tetraphenylethylene (TPE) derivatives have been proved to be typical aggregation-induced emission (AIE) luminogens when they were aggregated in the free three-dimensional space. In order to reveal the effect of the dimensional degree on AIE property of TPEs, we utilized tetra(4-hydroxyphenyl)ethylene (TPE-4OH) and 1,4-benzenediamine diazonium salt (BD) to fabricate the ultrathin films (TPE-4OH/BD LBL SA film) through layer-by-layer self-assembled technique. The interaction between TPE-4OH and BD in the films was converted from electrostatic force and hydrogen-bond to covalent bonds through photodecomposition of diazonium groups under UV irradiation. Fluorescence emission spectroscopy, UV-Vis absorption spectroscopy and atomic force microscope were carried out to evaluate the relationship between bilayer number and photoluminescence of the TPE-based self-assembled films. The experimental results showed that the TPE-based film with three bilayers only displayed AIE character, whereas the fluorescence of the film became randomly changed if the bilayer number was above three. It is supposed that the fluorescence property of the TPE-4OH/BD LBL SA film with limited molecular length in z-axis and infinite aggregation space in x-and y-axis is dominated by two competitive effects, one is the partial restriction of intramolecular rotation through short inter-molecular interactions in cross-linked structure of TPE-4OH/BD, and the other is deactivation of its excited state through unrestricted intramolecular rotations or π-π interactions.     

聚酰胺-胺树状大分子的合成与荧光性质的研究

以乙二胺为核，合成了不同代数的树状大分子，用元素分析、红外光谱、核磁共振进行了结构表征．荧光分析表明，整代的树状大分子具有荧光发光性能，通过测定与不同金属离子(M=Cu^2 ，Ni^2 ，Zn^2 ，Fe^3 ，Cr^3 ，Eu^3 )配位后的荧光性质，发现少量金属离子的加入，荧光强度变化不大．但无论是一代(1．0G)还是二代(2．0G)树状大分子，Fe^3 和Cr^3 的加入均使荧光强度明显增加．     

Carbazole tricationic salt: A novel potential two-photon fluorescent DNA probe for nucleic imaging of cells

A new carbazole tricationic salt, 4,4′-(1E,1′E)-2,2′-(9-(2-(1-(2-hydroxyethyl)pyridinium-4-yl)ethyl)-9H-carbazole-3,6-diyl) bis(ethane- 2,1-diyl) bis(1-(2-hydroxyethyl)pyridinium) iodide (THEPC) was synthesized. Photophysical experiments have shown that THEPC has large two-photon excited fluorescence action cross-sections (33 GM in the presence of DNA), which ranks THEPC as a good biological fluorophore. The results from electronic absorption, circle dichroism and single-/two-photon fluorescence emis-sion spectra suggest that THEPC can strongly bind to DNA, with an intrinsic binding constant of 5.79 × 106 L mol–1. THEPC has better photostability under one- or two-photon excitation conditions. Finally, the staining photos from two-photon fluorescence microscopy (TPM) show that THEPC can exclusively label the nucleus with high contrast and without image distortion. These re-markable properties and optimized imaging ability make THEPC an attractive DNA probe in TPM.