新基激复合物探针检测指定序列DNA

研究目的是拓展基激复合物荧光探针方法在检测指定序列DNA中的应用。实验选择细胞色素P450 CYP2C9基因中容易发生突变的包含24个碱基的基因片段作为靶点DNA,选择两个分开的与靶点碱基相对应的包含12碱基的寡核苷酸作为探针,将荧光集团连接到探针末端3′或5′磷酸基上形成荧光探针,两个荧光探针与靶点DNA杂交后自动装备基激复合物荧光系统,实验考察芘的新衍生物与不同荧光团配对、荧光团连接不同位置、不同激发波长对基激复合物形成及发射光谱的影响,芘的新衍生物探针形成的基激复合物在505 nm的特征发射光谱最强,伴随着单体荧光的猝灭和大约120～130 nm的Stokes位移,大大减少了DNA检测过程中的背景干扰,灵敏度高,而且这对荧光物质形成的基激复合物对所处的空间位置及微环境非常敏感,可尝试用于基因遗传多态性的识别。     

芘与1,4—二氰基苯形成的三分子激基复合物

本文用稳态和瞬态荧光光谱技术研究了芘与１，４－二氰基苯体系形成三分子激基复合物的条件。测定了该体系中激基缔合物，激基复合物，三分子激基复合物的稳态荧光光谱及荧光强度随时间变化的行为和特性，测定了芘在苯溶液中的荧光衰减寿命，讨论了三分子激基复合物形成的光物理机理。     

TADF激基复合物主体材料提升溶液法制备蓝色荧光有机发光二极管的效率

为了提升溶液法制备的蓝色荧光有机发光二极管(OLEDs)的效率,采用了基于热激活延迟发光(TADF)的激基复合物作为主体材料。TADF激基复合物主体可以利用反向系间窜跃上转换形成单线态激子并将能量传递到客体,从而可以同时利用发光层中的三线态激子和单线态激子,以提升蓝色荧光器件的效率。选择蓝色荧光材料1-4-Di-[4-(N,N-diphenyl)amino]styryl-benzene(DSA-ph)作为客体发光材料,4,4′,4″-T-ris(carbazol-9-yl)triphenylamine(TCTA)掺杂1,3,5-Tri(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl)(TPBi)作为热激活延迟荧光激基复合物主体,通过溶液法制备了蓝色荧光OLEDs。通过测试TCTA,TPBi以及TCTA掺杂TPBi的光致发光光谱发现,与TCTA和TPBi相比,TCTA掺杂TPBi的光致发光谱(PL)发生了明显的红移(峰值波长变为437 nm),而且光谱变宽,证明了TCTA∶TPBi激基复合物的形成。通过对于DSA-ph掺杂激基复合物主体的薄膜与DSA-ph掺杂poly(methyl methacrylate)(PMMA)的薄膜进行PL测试发现,两者发光峰相同,都是来自DSA-ph的发光,说明激基复合物主体将能量传递到了DSA-ph;DSA-ph的吸收光谱与激基复合物主体的PL光谱存在很大重叠,说明激基复合物主体与DSA-ph的能量传递非常有效;通过对激基复合物主体掺杂不同浓度客体的薄膜进行瞬态PL衰减测试发现,与纯DSA-ph的寿命相比,DSA-ph掺杂激基复合物主体之后其寿命会延长,纯DSA-ph的寿命只有1.19 ns,DSA-ph掺杂激基复合物主体的荧光衰减曲线与激基复合物主体的荧光衰减曲线相似,这进一步证明了激基复合物主体将能量传递到了DSA-ph。研究了主体引入以及DSA-ph掺杂浓度对器件性能的影响。对于器件的亮度、电流密度、电压、电流效率、电致发光光谱等参数进行了测试,与不采用激基复合物主体的器件相比,采用激基复合物主体的器件性能明显改善,在DSA-ph掺杂浓度为10%时,器件亮度从2133.6 cd·m^-2提升到了3597.6 cd·m^-2,器件效率从1.44 cd·A-1提升到了3.15 cd·A-1,发光峰只有来自DSA-ph的发光。采用TADF激基复合物主体的方法有潜力实现溶液法制备的高效蓝色荧光OLEDs。     

混合发光层有机电致发光器件中的多重成分发射

以等摩尔空穴传输材料TPD和电子传输材料PBD组成结构为ITO/TPD/TPD∶PBD/PBD/Al的混合物发光层有机电致发光(EL)器件,观察到了相对于组成材料的荧光光谱红移的宽发射带。通过比较EL光谱,光致发光光谱及EL光谱分解,表明电致发光中同时包含单体发射、激基复合物和电荷对复合物的发射。激基复合物为TPD的激发态TPD*与PBD的基态相互作用形成TPD*PBD类型的复合物,电荷对复合物是带电荷的空穴传输分子(D+)的空穴和电子传输分子(A-)的电子交叉复合而形成的(D+-A-)*复合物。各激发态在电场作用下呈现不同的形成机理和复合过程,并且单体发射和激发态复合物的比例随电场而变化,导致发射光谱随电场增强而蓝移。该器件的最高亮度和最大外部量子效率分别为240 cd·(cm2)-1和0.49%。有机固态界面激基复合物或电荷对复合物的发射常出现宽的红移发射带,是调节发光颜色的有效手段。     

聚β-乙烯基萘与1,4-二氰基苯形成的三分子激基复合物

本文旨在研究聚β-乙烯基萘链内激发态缔合物与基态受体分子1,4-二氰基苯相互作用后,形成三分子激基复合物的机理,用稳态和时间分辨荧光光谱技术证明了分子间的三分子激基复合物形成机理:测定了分子内激基缔合物的形成速度; 三分子激基复合物的形成速度常数,详细讨论了由激发态激基缔合物形成分子间三分子激基复合物的处理模型。     

一种对Fe(Ⅲ)进行裸眼识别和检测探针的荧光性质

设计合成了甲苯2,4-二异氰酸酯桥联纳米Fe3O4和罗丹明6G的PEG基荧光探针试剂。并用红外光谱、热重分析、透射电镜方法进行了表征。该探针与Fe3+结合显示红色,可以作为一种裸眼检测的试剂用于溶液中Fe3+的检测。该探针对Fe3+具有很强的选择性和高的灵敏性,荧光滴定法研究表明,对Fe3+的检测的灵敏度达到l.5×10-9 mol.L-1,即使溶液中在Fe2+,Mn2+,Ni 2+,Y3+,Eu3+,Ce3+,La3+,Pr3+,Cd2+,Cr3+,Sm3+,Cu2+和Zn2+等共存的条件下,该荧光探针能够高选择的识别出Fe3+,检测不受干扰。而且该探针分子能够穿透HeLa细胞检测细胞内的Fe3+,对细胞有较好的标记功能。该荧光探针试剂有很高的水溶性,且合成过程简单,易于操作。     

光谱法研究3H-吲哚季铵盐探针分子与牛血清底的相互作用

合成了一种新型的荧光探针分子2-(对-十二烷基氨基)苯基-3, 3-二甲基-5-乙酯基-3H-吲哚基-甲基-二-十六烷基碘化铵, 并运用荧光光谱探讨它与牛血清蛋白的作用. 结果表明, 探针分子与牛血清蛋白(BSA)的结合作用可使3H-吲哚的荧光强度增强, 而对蛋白质却具有猝灭性质, 其结合常数和结合位点数分别为Ka=1.995×105 dm3*mol-1和n=1.12.     

甲苯、萘、蒽与1.4-二氰基苯形成的激基复合物荧光光谱的研究

比较了甲苯、萘、蒽在与1.4-二氰基苯(DCB)形成激基复合物能力上的差别,估算了它们与DCB形成激基复合物的活化能分别为0.48、1.07、1.22kcak/mol。根据其荧光光谱、活化能和激发态分子电子云密度的分布,指出影响激基复合物形成的因素,除了电子电离能和电子亲和力外,还有激发态分子的电子云密度分布和分子的体积效应。在与DCB形成激基复合物的能力上应该是甲苯>萘>蒽。苯环与苯环相重叠可能是比较有利的互叠方式。     

白色有机电致发光器件中多组份电致激基复合物形成及抑制

从荧光-磷光复合结构的有机电致发光器件的研究入手,采用OXD-7作为蓝色荧光发光层,Ir(MDQ)2acac掺杂在母体材料作为红橙磷光发光层,设计制备了双波段白光有机电致发光器件。研究中发现,OXD-7,Alq3和NPB的三组分协同作用可以导致电致激基复合物的产生,以及由此导致的光谱红移,并使得器件发光效率降低。通过插入TDAF中间层可以有效地抑制激基复合物的产生,同时,通过控制载流子传输的平衡,以及磷光材料的掺杂浓度,可以获得器件发光亮度、效率的提升。     

基于激基复合物激发态的电致发光材料与器件研究进展

具有分子间电荷转移激发态特性的激基复合物(Exciplex)体系,由于前线分子轨道的分离特性——最高占有轨道(Highest occupied molecular orbital,HOMO)集中分布于给体分子上,最低空轨道(Lowest unoccupied molecular orbital,LUMO)集中分布于受体分子上,因此具有极小的单线态-三线态能级差(ΔE_st)以及热活化延迟荧光(Thermally activated delayed fluorescence,TADF)特性。因此,激基复合物体系的理论内量子效率可以达到100%。由于构建激基复合物体系的给体分子具有空穴传输特性,受体分子具有电子传输特性,因此,激基复合物体系具有平衡的载流子迁移特性,这使得激基复合物体系在作为发光层材料以及混合主体材料制备电致发光器件时具有平衡载流子迁移、扩大激子复合区域、提高器件效率以及降低效率滚降的优势。本文将讨论和总结基于激基复合物激发态体系的电致发光材料与器件基本原理、设计思路以及近期的研究进展。     

Fluorescence study of inter- and intramolecular interactions in poly(p-N,N-dimenthylaminostyrene-co-9-vinylantracene)

A new exciplex-forming polymer, poly(p-N, N-dimethylaminostyrene-co-9-vinylanthracene) (PDMA-AN, DP ≈ 25) was prepared by copolymerization of p-N, N-dimethylaminostyrene and 9-vinylanthracene. Exciplex formation was observed both in the fluid media and a polymer film. The fluorescence spectrum of PDMA-AN is characterized by the appearance of a high-energy exciplex formed by the neighboring pendant 9-anthryl (AN) and p-N, N-dimethylanilino (DMA) groups, which is shifted by approximately 85 nm to shorter wavelengths in comparison with the emission band of the intermolecular exciplex formed by the monomer model anthracene-p-N, N-dimethylaminotoluene (DMAT). The polymer conformation appropriate for the formation of this state exists prior to the initial excitation and is partially eclipsed. The effects of concentration and polarity of the solvent on the flourescence emission are discussed. A red shift of the maximum wavelength of the flourescence band as a function of concentration was found in a nonpolar solvent (toluene). However, in a relatively polar solvent (1,2-dichloroethane), a shoulder peak at a longer wavelength gains in intensity with increasing concentration. These phenomena are attributed to the increase of the contribution of the normal intermolecular exciplex state in which the interacting AN-DMA groups achieve an eclipsed and sandwiched conformation.     

基于激基复合物纯正发射的有机电致发光器件性能

利用聚合物三苯基二胺衍生物(Poly-TPD)掺杂2,5-双(5-叔丁基-2-苯并恶唑基)噻吩(BBOT)作为器件发光材料,研制了基于激基复合物纯正发射的有机电致发光器件.器件的具体结构为:ITO/PEDOT:PSS(25 nm)/Poly-TPD:BBOT( 1:1,80 nm)/Al(70 nm).研究结果表明,该...     

Movement of Polymer Segments by Exciplex Emission of Pyrene and N,N-Dimethylaniline at the Polymer–Silica Interface

Intermolecular interaction between pyrenyl units linked on the silica surface and N,N-dimethylaniline (DMA) units of polymer segments coated on the silica was investigated. Exciplex emission between these units was observed. The spectral shape and the intensity of the exciplex emission depended on the sample preparative conditions. Emission decay curves had no rise components, which showed that preformed ground-state complexes between pyrene and DMA existed and there were various microenvironmental sites around the preformed complexes just after sample preparation. Annealing of the samples made the exciplex emission wavelength shift and its intensity increase, which meant that polymer segments that contacted with the silica surface moved to make the stable conformations during annealing. It was revealed that DMA units of polymer segments are more stable when they face to the polymer–silica interface than when they become part of the polymer bulk. After the samples were kept at room temperature for 1 month, the spectra of all the samples became the same, which showed that the most stable conformations of the polymer segments were at the polymer–silica interface.     

Analysis of the Effects of Protic,Aprotic, and Multi-Component Solvents on the Fluorescence Emission of Naphthalene and its Exciplex with Triethylamine

The emission spectra of naphthalene (NP)–triethylamine (TEA) systems were measured under steady-state illumination conditions in some protic and aprotic solvent-tetrahydrofuran (THF) mixtures. The fluorescence spectrum of the NP–TEA system in THF could be separated into two component bands (band A at 329 nm (fluorescence of NP) and band B at 468 nm (emission from an intermolecular exciplex)). The intensities of bands A and B decreased with increasing solvent polarity. The intensity of band B also decreased owing to the hydrogen-bonding interaction between TEA and protic solvents, but in this case the intensity of band A increased. The decrease in the intensity of band A with increasing solvent polarity is considered to be caused by the enhanced formation of an ion-pair parallel to the formation of an exciplex with increasing solvent polarity. The decrease in the intensity of band B is considered to be caused by the enhanced formation of ion-pair both parallel to and through the formation of the exciplex. The increase in the intensity of band A and the decrease in that of band B upon the addition of protic solvents is caused by the decrease in the concentration of free TEA. Acetonitrile only has a polar effect and trichloroacetic acid only has a hydrogen-bonding (protonation) effect, while alcohols have both the effects.     

Intramolecular exciplexes in the electrogenerated chemiluminescence of 1-amino-3-anthryl-(9)-propanes

The electrogenerated chemiluminescence (ECL) of five 1-amino-3-anthryl-(9)-propane derivatives was studied in tetrahydrofuran at a rotating platinum ring-disc electrode and in square-wave voltage experiments. In addition to the broad emission band of the intramolecular exciplexes in the ECL-spectra the luminescence of the local excited anthracene moiety was found, the intensity of which was considerably smaller than in the fluorescence spectra. An increase of the ECL intensity by 16% to 24% in a magnetic field and the results of energy transfer experiments in mixed ECL systems suggest the participation of triplet states in the ECL process. A mechanistic interpretation is given involving the intramolecular triplet exciplex and the triplet state of the anthracene moiety beside the emitting singlet exciplex as primary products in the electron transfer between the electrogenerated ion radicals.     

Spectroscopic diagnostics of barrier discharge plasmas in mixtures of zinc diiodide with inert gases

The spectral characteristics of the emission of gas discharge atmospheric pressure plasmas in mixtures of zinc diiodide vapor with inert gases (He, Ne, Ar, Kr, and Xe) are investigated. The formation of a gas discharge plasma and the excitation of the components of a working mixture were performed in a high-frequency (with a repetition frequency of sinusoidal voltage pulses of 100 kHz) barrier discharge. The gas discharge emission was analyzed in the spectral range 200–900 nm with a resolution of 0.05 nm. Emission bands of ZnI(B-X) exciplex molecules and I₂* excimer molecules, lines of inert gases, and emission bands of XeI* exciplex molecules (in Xe-containing mixtures) were revealed. It is ascertained that the strongest emission of ZnI* molecules is observed in ZnI₂/He(Ne) mixtures. The regularities in the spectral characteristics of the gas discharge plasma emission are considered.     

Emission characteristics of plasma based on xenon–rubidium bromide mixture

Luminescence spectra of a longitudinal pulse-periodic discharge in xenon mixture with rubidium bromide vapors (Xe–RbBr) are studied experimentally at low pressures. The conditions leading to the appearance of intense bands of ultraviolet radiation of exciplex XeBr* molecules in the spectral interval between 200 and 400 nm are found. The highest yield of UV radiation of XeBr* molecules is achieved when the temperature of discharge-tube walls is equal to 750°C. A maximum power of UV radiation from the entire plasma volume as high as 4.8 W is obtained.     

A compact LED-based module for DNA capillary electrophoresis

A setup consisting of a bifurcated optical fiber made from high-transmission fused-silica cores with relatively high numerical apertures (NA=0.22), high-power cyan light-emitting diodes (LEDs) and Peltier cooling elements controlled by a proportional–integrative–derivative (PID) module is introduced to replace bulky, power- consuming lasers conventionally used in laser induced fluorescence (LIF) microchip capillary electrophoresis (μCE). The output fiber beam size, divergence, power distribution and power stability over time are documented. A modified epifluorescence microscope arrangement is used in conjunction with a compact fixed spectrometer aligned with a cooled charge-coupled device (CCD) camera for added sensitivity. Fluorescent dyes such as fluorescein, 6-carboxyfluorescein (6-FAM) and rhodamine B can be detected in cyclic olefin copolymer (COC) and glass microchannels at submicromolar levels. A single-stranded DNA oligonucleotide (10-mer) labeled with 6-FAM is also detected with reasonable signal-to-noise ratio when electrophoretically migrated at 100 V/cm. The compact LED excitation system presented herein will allow using capillary electrophoresis for DNA detection in compact mobile devices.     

A powerful broad band tunable dye laser

Perchloric acid solutions of 4 methylumbelliferone pumped by a second harmonic of ruby provide a high efficiency (20% conversion yield of pumping source) broad band (5600-4600 Å) tunable dye laser. Some effects of chemical quenching on the efficiency of this protonic exciplex laser were investigated.     

二甲氧基蒽－蒽醌体系分子内激发态复合物形成的结构条件与溶剂效应

本文报道了电子给体二甲氧基蒽(DMA)和电子受体蒽醌(AQ)以双酚A(BA)和对苯二酚(OP)连接起来的双发色团分子的合成和光谱性质研究,并根据光谱数据和荧光光谱,讨论了激发态复合物形成的结构因素和溶剂效应。