基于共轭高分子复合物能量转移的非标记DNA检测

非标记DNA检测是一种高灵敏度、高选择性的DNA检测方法, 具有重要的科学和社会意义. 本文采用交叉偶联法制备了水溶性阳离子共轭聚合物: 聚(9,9-双(6'-N,N,N-三甲胺盐-己烷基)-芴亚苯基)(PFP); 利用氧化加成聚合反应制备了水溶性阴离子共轭聚合物: 聚(3-噻吩乙酸钠)(P3TSA). 通过核磁共振氢谱(¹H NMR)、傅立叶变换红外光谱(FTIR)等对其结构进行了表征. PFP与P3TSA通过静电相互作用形成稳定的高分子复合物. 利用紫外-可见光谱(UV-vis)和荧光发射光谱证明共轭高分子复合物能够发生能量转移. 保持PFP的浓度不变, 高分子复合物能量转移效率(ETEF)随着P3TSA浓度的增加而逐渐增大. 选取ETEF较高的样品, 考察了DNA探针用量对高分子复合物ETEF的影响. 随着DNA探针浓度的增加, ETEF逐渐减弱. 最后, 利用0.2 nmol DNA探针进行了DNA杂交配对检测. 实验结果表明, 这种检测方法可以明显区分完全互补配对、双碱基错配和非完全互补配对的目标DNA. 简而言之, 我们成功发展了一种基于共轭高分子复合物能量转移、具有高选择性的非标记DNA检测方法.     

Surfactant Effect on Energy Transfer between Cationic Conjugated Polymer and Dye-Labeled Oligonucleotide

We report a convenient and effective method to enhance the signal output of dye-labeled oligonucleotide sensitized by cationic conjugated polymers (CCP). Sodium dodecyl sulphate (SDS) is utilized to regulate the interaction between CCP and dye-labeled single-stranded DNA in order to reduce the dye self-quenching within the CCP/DNA complexes. Improvement of CCP-sensitized dye emissison in the presence of SDS relative to that in the absence of SDS is observed, which reveals the importance of reducing CCP charge density in improving the energy transfer from CCP to dye-labeled probes.     

表面活性剂对共轭聚合物荧光性质及电荷转移的影响

探讨了表面活性剂存在下, 水溶性阴离子共轭聚合物聚[5-甲氧基-2-(3-磺酰化丙氧基)-1,4-苯撑乙烯](简写为MPS-PPV)的微环境变化对荧光性质及电荷转移的影响. 结果表明, 阳离子表面活性剂及非离子表面活性剂使MPS-PPV荧光增强, 阴离子表面活性剂使其荧光先增强后减弱; 在MPS-PPV/表面活性剂体系中加入电子接受体Pd^2＋, 发现非离子表面活性剂体系的荧光猝灭效率提高, 阴离子及阳离子表面活性剂体系荧光猝灭效率下降. 此研究对研制基于阴离子共聚物的新型生物化学传感器具有一定的指导意义.     

Optically Active Nanostructured ZnO Films

Inorganic nanomaterials endowed with hierarchical chirality could open new horizons in physical theory and applications because of their fascinating properties. Here, we report chiral ZnO films coated on quartz substrates with a hierarchical nanostructure ranging from atomic to micrometer scale. Three levels of hierarchical chirality exist in the ZnO films: helical ZnO crystalline structures that form primary helically coiled nanoplates, secondary helical stacking of these nanoplates, and tertiary nanoscale circinate aggregates formed by several stacked nanoplates. These films exhibited optical activity (OA) at 380 nm and in the range of 200–800 nm and created circularly polarized luminescence centered at 510 nm and Raman OA at 50–1400 cm^?1, which was attributed to electronic transitions, scattering, photoluminescent emission, and Raman scattering in a dissymmetric electric field. The unprecedented strong OA could be attributed to multiple light scattering and absorption‐enhanced light harvesting in the hierarchical structures.     

手性溶剂诱导非手性物质手性的研究进展

手性溶剂诱导非手性物质产生手性是目前合成手性物质的主流方法之一。与传统的手性物质合成方法相比,手性溶剂诱导法不仅避免了使用昂贵的手性试剂,还能扩大合成手性物质的结构范围,具有潜在的应用前景。目前,手性溶剂诱导方法适用范围已经涵盖了有机小分子、低聚物和聚合物体系。本文主要对手性溶剂诱导方法发展的历史背景,手性溶剂诱导小分子及低聚物的手性,手性溶剂诱导非手性聚合物产生超分子手性,主要包括π-共轭聚合物和σ-共轭聚合物这几个方面展开了综述。     

苯并三噻吩共轭聚合物的合成及其在有机光伏中的应用

以三(二亚苄基丙酮)二钯(Pd_2(dba)_3)为催化剂,三甲苯基磷(P(o-tol)_3)为配体,4,3'-十二烷基-2,2'-联二噻吩(M1)和2,8-二溴-5-(2-己基癸基)苯并三噻吩(M2)为单体,采用Stille交叉偶联反应,合成了基于苯并三噻吩和联二噻吩单元的共轭聚合物(PBTT)。采用热重分析、紫外-可见分光光度计及电化学分析分别研究了聚合物PBTT的热性能、光学性能和电化学性能。结果表明:聚合物PBTT具有优异的热稳定性和低的最高占有轨道能级(HOMO);聚合物薄膜最大吸收峰位于469 nm,光学能带隙为2.10 eV;将聚合物与[6,6]-苯基-C_(61)-丁酸甲酯(PC_(61)1BM)共混材料作为活性层制作了本体异质结构太阳能电池器件,在模拟太阳光源AM 1.5 G 100 mW/cm~2照射条件下,该器件获得了高达1.00 V的开路电压,初步的能量转化效率为0.43%。     

荧光共轭聚合物传感器用于病原体检测的研究进展

以共轭聚合物为基础的传感器用于检测病原体是现代临床医学发展的一个新方向. 综述了近十年来聚二乙炔(PDA)以及聚苯撑乙炔撑(PPE)等共轭聚合物传感器用于病原体检测的研究进展.     

Chirality Transfer and Memory of Chirality in Gold‐Catalyzed Reactions

Over the last few years, gold‐catalyzed reactions that involved chirality transfer and memory of chirality (MOC) have emerged as a powerful tool in enantioselective synthesis. This technique has allowed for the single‐step synthesis of enantioenriched compounds from readily available starting materials. This Focus Review discusses this emerging field with an emphasis on mechanistic aspects and their applications in synthetic organic chemistry.     

Rhodium-Catalyzed Pauson–Khand-Type Cyclization of 1,5-Allene-Alkynes: A Chirality Transfer Strategy for Optically Active Bicyclic Ketones

An efficient chirality transfer in the [RhCl(CO)₂]₂-catalyzed [2+2+1] cyclization of optically active axially chiral 1,3-disubstituted allenynes with CO to access optically active bicyclopentenone compounds has been developed. The distal C=C bond of allenes reacted with the alknye unit and CO to afford [4.3.0]-bicyclic products with high ee values under mild reaction conditions with an excellent selectivity.     

基于水溶性共轭聚合物分子刷的高灵敏凝血酶生物传感器

以刷子状水溶性共轭聚芴（PFNI）为传感材料,以荧光素标记的核酸适体（FAM-apt15）为探针,设计了一种检测凝血酶的高灵敏度蛋白质传感器. PFNI的刷状结构带有大量正电荷,与负电荷的柔性单链核酸探针形成静电复合物,使能量供体（PFNI）与受体（FAM）之间的距离较近,发生高效荧光共振能量转移（Föster resonance energy transfer,FRET）. 当探针与靶凝血酶结合时,形成刚性且体积较大的G-四链体/凝血酶复合物,由于体积位阻和密集的刷子的阻碍作用,PFNI与FAM之间的距离被拉大,FRET效率显著降低. 对缓冲溶液中凝血酶检测的最低检测限可达0.05 nmol/L. 与基于线型共轭聚合物的蛋白质检测方法相比,灵敏度提高了至少一个数量级.     

基于阳离子型共轭聚合物和核酸适体的腺苷检测新方法

建立了一种基于阳离子型共轭聚合物和核酸适体的腺苷检测新方法. 荧光素修饰的短链DNA与腺苷的核酸适体部分互补, 形成双链DNA; 阳离子型共轭聚合物通过静电作用与双链DNA结合, 发生高效率的荧光共振能量转移(FRET). 加入腺苷后, 腺苷与核酸适体发生特异性结合, 导致双链DNA分解成单链, 使静电吸引力下降, 能量转移效率降低. 通过阳离子型共轭聚合物对单双链DNA的高效识别, 可快速简易地检测出腺苷.     

基团转移活性聚合物的接枝共聚

以阴离子聚合法合成的窄分布聚苯乙烯（ＮＤＰＳ）进行氯甲基化后,再与由基团转移聚合法合成的活性聚甲基丙烯酸甲酯（ＰＭＭＡ）进行大分子反应,得到了主链为聚苯乙烯,支链为聚甲基丙烯酸甲酯的接枝共聚物（ＰＳｔｇＰＭＭＡ）;探讨了聚合物的合成条件,ＧＰＣ测试结果表明,得到的接枝共聚物的分子量和设计分子量相近且主链和支链分子量均可较好的控制．利用扫描电镜、核磁和红外技术对ＰＳｔｇＰＭＭＡ的形态、结构进行了表征．     

Synthesis of Polymer Brushes Using Atom Transfer Radical Polymerization

Atom transfer radical polymerization (ATRP) is a robust method for the preparation of well‐defined (co)polymers. This process has also enabled the preparation of a wide range of polymer brushes where (co)polymers are covalently attached to either curved or flat surfaces. In this review, the general methodology for the synthesis of polymer brushes from flat surfaces, polymers and colloids is summarized focusing on reports using ATRP. Additionally, the morphology of ultrathin films from polymer brushes is discussed using atomic force microscopy (AFM) and other techniques to confirm the formation of nanoscale structure and organization.

Formation of polymer brushes by ATRP.     

圆偏振光在手性聚合物合成与结构调控中的应用

手性是自然界中普遍存在的有趣现象之一,在生命体中手性大分子特有的不对称结构在维持生命过程、新陈代谢和进化等面均起着决定性作用.受此启发,合成具有新型结构的光学活性聚合物,研究其独特的物理化学性质和功能已成为当今高分子领域研究的热点.左旋和右旋的圆偏振光已被广泛应用于氨基酸衍生物的不对称光合成、光分解和去消旋化反应,以及诱导含有偶氮苯或三苯胺等特定功能基团的超分子组装体或无机纳米粒子形成稳定螺旋结构.本文详细地介绍了圆偏振光辐照在手性聚合物合成与螺旋结构调控中的应用,初步揭示了圆偏振光的作用机制以及优势,归纳总结了已取得的研究进展,并对圆偏振光在手性聚合物合成与结构调控中的应用及发展进行了简单的评述和展望.     

Optically Active Helical Vinylterphenyl Polymers: Chiral Teleinduction in Radical Polymerization and Tunable Stereomutation

Helical vinyl aromatic polymers are emerging as interesting chiral materials due to their dynamic tailorability, synthetic simplicity, and outstanding chemical and physical stabilities. This Personal Account discusses long‐range chirality transfer in the radical polymerization of vinylterphenyl monomers and tunable stereomutation of the resultant polymers. It begins with a general introduction to the design, synthesis, and characterization of helical poly{(+)‐2,5‐bis[4′‐((S)‐2‐methylbutyloxy)phenyl]styrene}, the first one of this series of polymers. Then, long‐range chirality transfer during radical polymerization of terphenyl‐based vinyl monomers is explained. After that, the chiroptical property control of the resultant polymers by means of the transition from kinetically controlled conformation to thermodynamically controlled conformation and external stimulus is described. This Personal Account concludes by discussing the advantages and disadvantages of the strategy of using vinylterphenyls to obtain optically active helical polymers and providing a short outlook, especially emphasizing the importance of tacticity on the chiroptical properties of polymers.     

A Fluorescent Linear Conjugated Polymer Constructed from Pillararene and Anthracene

Over the past few years, conjugated polymers (CPs) have aroused much attention owing to their rigid conjugated structures, which can perform well in light harvesting and energy transfer and offer great potential in materials chemistry. In this article, we fabricate a new luminescent linear CP p(P[5](OTf)₂-co-9,10-dea) via the Sonogashira coupling of 9,10-diethynylanthracene and trifluoromethanesulfonic anhydride (OTf) modified pillar[5]arene, generating enhanced yellow-green fluorescence emission at around 552 nm. The reaction condition was screened to get a deeper understanding of this polymerization approach, resulting in an excellent yield as high as 92% ultimately. Besides the optical properties, self-assembly behaviors of the CP in low/high concentrations were studied, where interesting adjustable morphologies from tube to sheet were observed. In addition, the fluorescence performance and structural architecture can be disturbed by the host–guest reorganization between the host CP and the guest adiponitrile, suggesting great potential of this CP material in the field of sensing and detection.     

基于阳离子型共轭聚合物与酶底物探针的磷酸酯酶检测新方法

建立了一种基于阳离子型共轭聚合物与酶底物探针的磷酸酯酶检测新方法. 阳离子型共轭聚合物通过静电吸引与荧光素修饰的带负电荷的三磷酸腺苷结合, 并发生荧光能量共振转移; 当加入磷酸酯酶时, 它可以催化底物三磷酸腺苷上的磷酸酯基团逐渐水解, 得到不带电荷的腺苷, 从而使阳离子型共轭聚合物得以释放, 能量转移效率下降. 实验结果表明, 能量转移效率下降的程度与酶的浓度相关. 该方法操作简单, 响应速度快, 灵敏度高, 易于扩展至其它能催化底物电荷密度变化的酶的检测, 而且还有望应用于对酶具有抑制作用的药物分子的筛选.     

Luminescent,Oxygen‐Supplying,Hemoglobin‐Linked Conjugated Polymer Nanoparticles for Photodynamic Therapy

Photodynamic therapy (PDT) is a promising method for cancer treatment. Two parameters that influence the efficacy of PDT are the light source and oxygen supply. Herein, we prepared a system for PDT using hemoglobin (Hb)‐linked conjugated polymer nanoparticles (CPNs), which can luminesce and supply oxygen. Hb catalyzes the activation of luminol, the conjugated polymer poly[2‐methoxy‐5‐(2‐ethylhexyloxy)‐1,4‐phenylenevinylene] (MEH–PPV) nanoparticles can absorb the chemiluminescence of luminol through chemiluminescence resonance energy transfer (CRET) and then sensitize the oxygen supplied by Hb to produce reactive oxygen species that kill cancer cells. This system could be used for the controlled release of an anticancer prodrug. The system does not need an external light source and circumvents the insufficient level molecular oxygen under hypoxia. This work provides a proof‐of‐concept to explore smart and multifunctional nanoplatforms for phototherapy.     

In Situ Optical Imaging of the Growth of Conjugated Polymer Aggregates

Understanding the mechanisms that contribute to conjugated polymer aggregate formation and growth may yield enhanced control of aggregate morphology and functional properties on the mesoscopic scale. In situ optical imaging of the growth of MEH‐PPV aggregates in real time in controlled swollen films shows that growth occurs through multiple mechanisms and is more complex than previously described. Direct evidence is provided for both Ostwald ripening and aggregate coalescence as operative modes of aggregate growth in solvent swollen films. These growth mechanisms have a distinct and strong impact on the evolution of morphological order of growing aggregates: while Ostwald ripening allows preservation of highly ordered morphology, aggregate coalescence occurs with no preferential orientation, leading to attenuation in degree of ordering.